Structure and Function of Vascular Plant Communities in Created and Restored Wetlands in Ohio Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Kay Christine Stefanik, B.S. Environmental Science Graduate Program The Ohio State University 2012 Dissertation Committee: William J. Mitsch, Advisor Gil Borher Charles Goebel Allison Snow Copyright by Kay Christine Stefanik 2012 Abstract Throughout Ohio there are a number of wetlands created or restored to fulfill requirements under Section 404 of the Clean Water Act. The purpose of these created/restored wetlands is to replace both habitat area and ecosystem processes of natural wetlands. The created/restored wetlands are usually monitored for vegetation structure, but rarely for ecosystem function. The purpose of this study was to examine vegetation development in created and restored wetlands from both a structural and functional standpoint. Structural and functional characteristics of the dominant vegetation of mitigation bank wetlands (<20 years of age) were examined from 2008-2010 for five wetland mitigation bank sites and compared to a natural and a created reference wetland sites. Wetlands were sampled for vegetation structure (species richness, Ohio floristic quality assessment index, Shannon-Wiener diversity index, and community diversity index) and function (aboveground net primary productivity and functional group composition of the dominant species). The mitigation wetlands were significantly different from the reference wetlands in terms of both structure and function (p<0.001), but the younger wetland mitigation sites were more similar structural (in terms of species richness and floristic quality) to the reference sites than the older mitigation sites. ii Development of vegetative structure and function was examined 15 to 17 years after wetland creation in a planted wetland and an unplanted wetland at the Olentangy River Wetland Research Park (ORWRP) on a monthly basis throughout the growing season from 2008 through 2010. Structural characteristics, as well as functional characteristics (aboveground net primary productivity, belowground net primary productivity, macrophyte nutrient concentration) were examined. The planted wetland had higher species richness (p=0.019), floristic quality assessment scores (p=0.002), and less area occupied by invasives (p<0.001) than the unplanted wetlands, while the unplanted wetland had higher aboveground net primary productivity than the planted wetland (p=0.006) over the course of three years. Planting may be beneficial even in a flow-through wetland that receives propagules from an adjacent river by reducing potential niches for invasive species, increasing species richness and increasing floristic quality. Open system flow-through chambers were used to measure gaseous carbon fluxes of gross primary productivity, respiration, and methane emissions associated with dominant macrophyte communities at the ORWRP over the growing season. Gas samples from the inflow and outflow pipes of the chambers were collected over 48-hr periods every month from April through September on odd hours between sunrise and sunset and twice nightly to estimate gross primary productivity (GPP) and respiration (R). Methane emissions were also examined from both the day and night samples. GPP averaged 13.94 ± 0.79 g CO2-C m-2 day-1, while respiration averaged 12.55 ± 0.54 g CO2C m-2 day-1. GPP differed by both month sampled and plant community sampled iii (p<0.001 and p=0.002, respectively). Median methane emissions from the sample plots was 12.81 mg CH4-C m-2 day-1 and differed by month (p<0.001) and soil temperature (p=0.049). Combining all three carbon fluxes, there is an overall uptake of carbon within the sample plots, suggesting that the wetlands are acting as overall carbon sinks. There was a net retention of carbon in the two experimental wetlands ranging from 160 to 195 g C/m2 year in 2010 and from 164 to 171 g C/m2 year in 2011. iv Dedication To my family and friends. v Acknowledgements I would like to thank all of the people who helped with field and lab work for the three projects, Blanca Bernal, Chris Cooley, Deblina Gosh, Rachelle Howe, Felice Forby, Kyle Kingma, Brent Macolley, Darryl Marois, Lynn McCready, Maggie Mohr, Christine Shannon, the Stefanik family, Maoqi Sun, Matthew Thibault, Jorge Villa-Betancur, Evan Waletzko, Li Zhang, and Yiding Zhang, as well as the Ohio Wetlands Foundation, Lorain County Metroparks, Hebron State Fish Hatchery, Slate Run Metropark and Davey Resource Group (Karen Wise and Ana Burns) for providing background information and site access. A special thanks to Brent Macolley and Matthew Thibault for their help with metabolism chamber construction and to Brent Macolley, Maggie Mohr, and Evan Waletzko for helping with metabolism chamber set up over the two years of the project. I would also like to thank the Ohio Wetlands foundation for providing support for the project (Ohio Wetlands Foundation Fellowship), as well as the U.S. Environmental Protection Agency (Agreements EM83329801-0 Cincinnati OH; MX95413108-0 Gulf of Mexico Program), National Science Foundation (grants CBET-1033451 and CBET0829026), the Environmental Science Graduate Program (ESGP Fay Fellowship), and the Olentangy River Wetland Research Park (Sipp Award) at The Ohio State University. Finally, thank you to my advisor and committee members for all of their comments, suggestions, and insights throughout the course of my research. vi Vita May 2003.........................................................Midview High School May 2007.........................................................B.S. Biology, Baldwin-Wallace College 2007 to present.................................................Graduate Teaching and Research Associate, The Olentangy River Wetland Research Park, Environmental Science Graduate Program, The Ohio State University Publications Stefanik, Kay C., and William J. Mitsch. 2012. Structural and functional vegetation development in created and restored wetland mitigation banks of different ages. Ecological Engineering, 39: 104-112. Mitsch, William J., Li Zhang, Kay C. Stefanik, Blanca Bernal, Amanda M. Nahlik, Christopher J. Anderson, and Maria E. Hernandez. 2012. Creating wetlands: A 15year experiment in self-design. BioScience. 62: 237-250. Fields of Study Major Field: Environment Science vii Table of Contents Abstract................................................................................................................................ii Dedication............................................................................................................................v Acknowledgments..............................................................................................................vi Vita.....................................................................................................................................vii List of Table.......................................................................................................................xii List of Figures...................................................................................................................xiii Chapters 1: Introduction......................................................................................................1 Chapter 2: Structural and functional vegetation development in created and restored wetland mitigation banks of different ages........................................................................11 2.1 Abstract............................................................................................................11 2.2 Introduction......................................................................................................12 2.3 Methods............................................................................................................16 2.3.1 Study Site................................................................................................16 2.3.2 Sampling Methods..................................................................................17 2.3.3 Structural Parameters..............................................................................18 2.3.4 Functional Parameters.............................................................................20 2.3.5 Statistical Methods..................................................................................21 2.4 Results..............................................................................................................23 viii 2.4.1 Structural and Functional Parameters.....................................................23 2.4.2 Hypothesis Testing..................................................................................24 2.4.3 Redundancy Analysis..............................................................................26 2.5 Discussion........................................................................................................27 2.5.1 Structure..................................................................................................27 2.5.2 Function..................................................................................................29 2.5.3 Mitigation Bank and Reference Wetland Comparison............................30 2.6 Conclusions......................................................................................................32 2.7 References........................................................................................................33 Chapter 3: Vegetation productivity of riverine planted and unplanted wetlands fifteen to seventeen years after creation............................................................................................48 3.1 Summary...........................................................................................................48 3.2 Introduction.......................................................................................................49 3.3 Materials and Methods......................................................................................52 3.3.1 Study Site................................................................................................52 3.3.2 Structural Characteristics........................................................................53 3.3.3 Functional Characteristics.......................................................................54 3.3.4 Statistical Analysis..................................................................................58 3.4 Results..............................................................................................................59 3.4.1 Experimental Wetlands..........................................................................59 3.4.2 Edge Vegetation.....................................................................................61 3.5 Discussion........................................................................................................62 ix 3.5.1 Structure.................................................................................................62 3.5.2 Function.................................................................................................64 3.5.3 Edge Vegetation.....................................................................................66 3.5.4 Conclusions............................................................................................66 3.6 References........................................................................................................67 Chapter 4: Metabolism and methane flux of dominant macrophyte communities in created riverine wetlands using open system flow through chambers...............................83 4.1 Abstract............................................................................................................83 4.2 Introduction......................................................................................................84 4.3 Methods............................................................................................................88 4.3.1 Study Site................................................................................................88 4.3.2 Chamber Design......................................................................................89 4.3.3 Sampling.................................................................................................90 4.3.4 Statistical Analysis..................................................................................91 4.4 Results..............................................................................................................92 4.5 Discussion........................................................................................................96 4.5.1 Gross Primary Productivity and Respiration..........................................96 4.5.2 Carbon Balance and Global Climate Change.........................................98 4.6 References......................................................................................................101 Chapter 5: Conclusions....................................................................................................114 References........................................................................................................................117 Appendix A: In-depth Site Descriptions..........................................................................133 x Appendix B: Regression Equations.................................................................................138 Appendix C: Mitigation Bank and Reference Wetland Vegetation.................................139 Appendix D: Olentangy River Wetland Research Park Experimental Wetlands Vegetation Community Maps from 2008-2011...............................................................173 Appendix E: Calculations for Metabolism Chambers.....................................................178 Appendix F: Statistical Tables.........................................................................................179 F.1 Chapter 2 Statistical Tables............................................................................180 F.1.1 Mitigation vs. Reference Sites..............................................................180 F.1.2 Age of Mitigation Bank Wetlands.........................................................182 F.1.3 Hydrology..............................................................................................183 F.1.4 Location in Ohio...................................................................................184 F.2 Chapter 3 Statistical Tables............................................................................185 F.2.1 Wetland Vegetation...............................................................................185 F.2.2 Nutrient Analysis...................................................................................187 F.2.3 Edge Vegetation.....................................................................................189 F.3 Chapter 4 Statistical Tables............................................................................190 F.3.1 Gross Primary Productivity...................................................................190 F.3.2 Respiration............................................................................................193 F.3.3 Methane.................................................................................................195 xi List of Tables Table 2.1: Year of creation, site and wetland areas, hydrology, hydrogeomorphic classification, soil type, and location of Ohio wetland mitigation banks and reference wetlands used in this study.................................................................................................41 Table 2.2: Average ± standard error of structural and functional parameters at each wetland site........................................................................................................................42 Table 2.3: Functional groups of dominant wetland plant species at the five mitigation sites and two reference sites...............................................................................................43 Table 3.1: Average ± standard error of structural and functional characteristics of the two experimental wetlands and edge area................................................................................75 Table 3.2: Functional classification and percent cover of the dominant plant communities in the planted and unplanted wetlands...............................................................................76 Table 3.3: Average nutrient content of aboveground biomass from August 2010............77 Table 4.1: Monthly average ± standard error of environment variables over the course of the growing season in 2010 and 2011..............................................................................107 Table 4.2: P-values from ANOVA and linear regression models for the dependent and environmental variables...................................................................................................108 Table B.1: Regression equations created for dominant species.......................................138 Table C.1: Plant species found at each site over the course of the study. Includes coefficient of conservatism and wetland indicator status for each species......................140 xii List of Figures Figure 2.1: Location of wetland sites within Ohio, USA..................................................44 Figure 2.2: Scatter plots of (A) aboveground net primary productivity of emergent plant zones (ANPP), (B) species richness, (C) ANPP over the entire wetland, and (D) floristic quality assessment index (FQAI) score with age for 5 mitigation bank wetlands.............45 Figure 2.3: Redundancy analysis (RDA) triplot of species, environmental variables, and mitigation bank sites..........................................................................................................46 Figure 2.4: Diversity-productivity scatter plot divided into four categories for mitigating wetland banks and reference wetlands...............................................................................47 Figure 3.1: This study was conducted in the two 1-ha experimental wetlands at the Olentangy River Wetland Research Park...........................................................................78 Figure 3.2: Monthly weighted aboveground biomass of the two wetlands.......................79 Figure 3.3: Accumulation of monthly weighted aboveground net primary productivity of the wetlands from 2008 to 2010........................................................................................80 Figure 3.4: Monthly belowground biomass of the two wetlands......................................81 Figure 3.5: Tree aboveground net primary productivity (ANPP) of the interior edge of each wetland.......................................................................................................................82 Figure 4.1: Diagram of large chamber setup...................................................................109 Figure 4.2: Average gross primary productivity of the five different samples groups....110 Figure 4.3: Monthly average and standard error of carbon flux of the sample plots.......111 xiii Figure 4.4: Monthly median methane emission for the sample plots..............................112 Figure 4.5: Carbon uptake and emission as CO2 in relation to solar radiation and temperature.......................................................................................................................113 Figure D.1 2008 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park................................................174 Figure D.2 2009 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park................................................175 Figure D.3 2010 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park................................................176 Figure D.4 2011 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park................................................177 xiv Chapter 1: Introduction Wetland creation and restoration as a means to mitigate the loss of natural wetlands due to human development has become common practice in the United States since the passage of the Clean Water Act in 1972. Under Section 404 of the Clean Water Act, a permit is required to dredge or fill any jurisdictional wetland (legally recognized wetland as determined by the Wetland Delineation Manual published by the Army Corps of Engineers; Mitsch and Gosselink 2007; Salzman and Thompson 2007). Under the permit program, the permit holder is required to mitigate wetland loss at a ratio of greater than 1:1, which helps ensure no-net loss of wetland area. The main reason behind the nonet loss policy is the large amount of wetland habitat that has been lost since preEuropean settlement. Through the 1970s, the United States had lost approximately 50% of wetland habitat since European settlement in the lower forty-eight states, while Ohio had lost around 90% (Dahl 1990). Unfortunately, there is a lack of human power, resources, and enforcement power by the Army Corp of Engineers, The U.S. Environmental Protection Agency, and various state agencies to ensure that permit requirements are met (Cole and Shafer 2002; Reiss el al. 2009). Because of this, not only are there problems with no-net loss goals not being achieved, but there is also an issue with created and restored wetlands not replacing the ecosystem function of natural wetlands that have been lost (NRC 2001). 1 Under a Section 404 permit, there are a few different options for mitigation. Two of the more common options for mitigation include creation or restoration on a local permit basis or creation or restoration on a larger scale through mitigation banks. Mitigation banks are large wetland complexes that are created without regard to one specific permit. Mitigation banks are monitored for approximately five years after creation or restoration. Wetland credits, based on the overall area of successful wetland habitat within the bank, are then sold to permit holders to fulfill their permit requirements (Reiss et al. 2009). Since mitigation banks are created without regard to one specific permit, there is no guarantee that in-kind replacement, or the replacement of the same type of wetland habitat will occur. While the same type of wetland function may not be replaced, mitigation banks are still beneficial, especially in a system where there is little permit enforcement and there is a failure rate of 40-60% in some states (NRC 2001; Cole and Shafer 2002; Reiss et al. 2009). There has also been concern over the ability of mitigation wetlands to meet the criteria for success within a 5-year time frame (Mitsch and Wilson 1996). Studies have found that it may take up to 20 years for vegetation characteristics to resemble that of natural wetlands (Balcombe et al. 2005; Spieles 2005; Gutrich et al. 2009). Construction techniques have also been linked to problems with wetland development. The removal or compaction of soil from a site has been shown to alter organic matter content and bulk density, which can inhibit the penetration of roots within the soil and reduce nutrient availability to the vegetation, thus hindering the establishment of plant species and primary productivity (Campbell et al. 2002; Bruland and Richardson 2005; Batilan-Smith 2 et al. 2009; Ahn and Dee 2011). It may take a number of years for a created wetland to develop soils similar to natural wetlands in terms of soil organic matter, nutrient content and seed bank (Choi 2004). Even if a wetland meets the criteria for success after 5 years, a wetland could be deemed unsuccessful in the future depending on the trajectory of succession in the wetland. At the five year point, it is quite possible that the trajectory of vegetation succession may not be fully visible (Matthews et al. 2009). Studies have shown that there tends to be an initial peak in structural parameters of a system, which then begin to decline over time (Fennessey and Roehrs 1997; Campbell et al. 2002; Balcombe et al. 2005; Spieles 2006; Gutrich et al. 2009). Future disturbances to a system will also likely alter the successional trajectories of a wetland. One way to accelerate the succession of a created or restored wetland may be through vegetation planting. Gutrich et al. (2009) found that wetlands in which there was a strong initial restoration effort (planting of wetland vegetation and contouring within basins) had higher floristic composition for plant species richness, number of native species, and number of hydrophytes. Not only can planting positively influence vegetation structural characteristics, but it may also be able to help increase the resiliency of a system to future disturbances. Newly created wetlands can be thought of as highly disturbed systems that will progress along a successional trajectory that will lead to a system that falls along the continuum from low quality to high quality ecosystems and from early to late successional types of vegetation (Suding and Cross 2006). The frequency and severity of disturbances to an ecosystem will also affect the length of time 3 spent in a particular successional stage, how often the ecosystem reverts to early successional stages, and the ability of an ecosystem to progress into later successional stages (Walker and del Moral 2008). Disturbances that affect the dominant species of a system more so than the minor species will likely have a greater impact on ecosystem processes than disturbances that primarily affect minor species. If there is a functional overlap between the minor and dominant species within an ecosystem, i.e. there are minor species that can maintain the functional roles if dominant species are damaged or destroyed, an ecosystem is much more likely to be resilient to disturbances (White and Jentsch 2001). Mitsch and Wilson (1996) suggested that the best approach to vegetation planting in created and restored wetlands may be to introduce as many native vegetation species as possible and allow the system to self-design and chose the species that are most appropriate for the system. While mitigation banks may help to ensure “no net loss” of wetland habitat is occurring, this does not guarantee that there is not a loss of wetland functional processes. Current monitoring practices of mitigation wetlands tends to focus on the soil, water, and vegetation of the system. Of these three parameters, vegetation is a widely used measure for the success of a wetland. Vegetation monitoring practices focus on the structural characteristics of the plants, such as percent vegetation cover, species richness, percent invasive species, and indicator status of the species present (Mitsch and Wilson 1996). Structural characteristics have been favored due to the speed and cost efficiency of the practices, but may not reflect ecosystem processes (Mitsch and Wilson 1996; Spieles 2005; Ahn and Dee 2011). It has been suggested that functional vegetation 4 characteristics (e.g. productivity and functional group composition) are better determinates of ecosystem processes than structural characteristics (Tilman et al. 1997). Functional characteristics are the physical, chemical and, biological processes that occur within a wetland (Marble 1992). Vegetation functional characteristics include net primary productivity, gross primary productivity, respiration, and functional group composition. Not only can functional characteristics aid in determining the success of created and restored wetlands, they can also aid in understanding the role that wetlands play in regional, landscape, and global patterns. Gross primary productivity is the main driver of the carbon cycle in wetlands. The gaseous carbon budget of a wetland is dependent on the amount of carbon taken up through photosynthesis and the amount of carbon lost through respiration and methane emissions (Whiting and Chanton 2001; Cornell et al. 2007; Yvon-Durocher et al. 2007). The difference between uptake and emissions determines if the wetland is acting as a carbon sink or a carbon source. The fate of carbon in wetland ecosystems is of great concern in regards to global climate change. Carbon dioxide and methane are two of the main greenhouse gases identified by the IPCC (2007). Of these two gases, methane has a global warming potential (GWP) of 25 relative to carbon dioxide, so a small change in levels of atmospheric methane will have a greater impact on global climate change than small changes in the level of carbon dioxide (IPCC 2007). Through understanding the balance of carbon in wetlands it is possible to determine if a wetland is acting as a carbon sink or a carbon source, and may provide information on the types of conditions necessary in created and restored wetlands to 5 constructed wetlands that function as carbon sinks. The goal of this study was to examine vegetation development in created and restored wetlands in Ohio from both a structural and functional standpoint. The specific objectives of this study were to: 1) Examine the structural and functional characteristics of the dominant vegetation of several mitigation bank wetlands <20 years of age and compare these to a natural wetland and a successful created reference wetland of similar age; 2) Compare development of vegetative structure and function in planted and unplanted wetlands maintained with identical hydrology for 15 to 17 years after the wetlands were created: and 3) Estimate gross primary productivity, respiration, methane emissions, and net carbon retention of dominant macrophyte communities in the wetlands using open system flow through chambers. Each objective is explored in its own chapter in this dissertation. All research was conducted in Ohio, USA, with chapter two examining mitigation sites in northern and central Ohio, and chapters three and four examining structural and functional characteristics in greater detail in the two experimental wetlands at the Olentangy River Wetland Research Park, The Ohio State University, Columbus, Ohio. The majority of the field research occurred during the growing seasons of April through September 20082011. 6 References Ahn, C., & Dee, S., 2011. Early development of plant community in a created mitigation wetland as affected by introduced hydrologic design elements. Ecological Engineering. 37, 1324–1333. Balcombe, C.K., Anderson, J.T., Fortney, R.H., Rentch, J.S., Grafton, W.M., & Kordek, W.S., 2005. A comparison of plant communities in mitigation and reference wetlands in the Mid Appalachians. Wetlands 25, 130–142. Bantilan-Smith, M., Bruland, G.L., MacKenzie, R.A., Henry, A.R., & Ryder, C.R., 2009. A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai’i. Wetlands 29, 1023–1035. Bruland, G.L., & Richardson, C.J., 2005. Spatial variability of soil properties in created, restored, and paired natural wetlands. Soil Science Society of America Journal 69, 273–284. Campbell, D.A., Cole, C.A., &Brooks, R.P., 2002. A comparison of created and natural wetlands in Pennsylvania, USA. Wetland Ecology and Management 10, 41–49. Choi, Y.D., 2004. Theories for ecological restoration in changing environment: Toward a 'futuristic' restoration. Ecological Research 19, 75-81. Cole, C.A., & Shafer, D., 2002. Section 404 wetland mitigation and permit success criteria in Pennsylvania, USA, 1986–1999. Environmental Management 30, 508– 515. Cornell, J.A., Craft, C.B., & Megonigal J.P., 2007. Ecosystem gas exchange across a created salt marsh chronosequence. Wetlands 27, 240-250. 7 Dahl, T.E., 1990. Wetlands Losses in the United States 1780s to 1980s. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC, l3 pp. Fennessey, S., & Roehrs, J., 1997. A Functional Assessment of Mitigation Wetlands in Ohio: Comparisons With Natural Systems. Ohio Environmental Protection Agency Division of Surface Waters, Columbus, OH. Gutrich, J.J., Taylor, K.J., & Fennessy, M.S., 2009. Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): the importance of initial effort for mitigation success. Ecological Engineering 35, 351–368. Intergovernmental Panel on Climate Change (IPCC) 2007. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds.) Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Marble, A.D., 1992. A guide to wetland functional design. Pp 1-14, CRC Press, Boca Raton, FL. Matthews, J.W., Spyreas, G. & Endress, A.G., 2009. Trajectories of vegetation-based indicators used to assess wetland restoration progress. Ecological Applications 19, 2093-2107. Mitsch, W.J., & Wilson, R.F., 1996. Improving the success of wetland creation and restoration with know-how, time, and self-design. Ecological Applications 6, 77– 83. 8 Mitsch, W.J., & Gosselink, J.G., 2007. Wetlands, 4th ed. John Wiley & Sons, Inc., Hoboken, NJ. National Research Council, 2001. Compensating for Wetland Losses under the Clean Water Act, Committee on Mitigating Wetland Losses. National Academies Press, Washington, DC. Reiss, K.C., Hernandez, E., & Brown, M.T., 2009. Evaluation of permit success in wetland mitigation banking: a Florida case study. Wetlands 29, 917–918. Salzman, J., & Thompson Jr., B.H., 2007. Environmental Law and Policy. Foundation Press, New York, NY. Spieles, D.J., 2005. Vegetation development in created, restored, and enhanced mitigation wetland banks of the United States. Wetlands 25, 51–63. Suding, K.N., & Cross, K.L., 2006. The dynamic nature of ecological systems: Multiple states and restoration trajectories. Foundations of Restoration Ecology (eds D.A. Falk, M.A. Palmer, & J.B. Zedler) pp. 190-209 Island Press, Washington, D.C. Tilman, D., Knops, J., Wedin, D., Reich, P., Ritchie, & M., Siemann, E., 1997. The influence of functional diversity and composition on ecosystem processes. Science 277, 1300–1302. Walker, L.R. & del Moral, R. 2008. Transition dynamics in succession: Implications for rates, trajectories, and restoration. New Models for Ecosystem Dynamics and Restoration (eds K. Suding & R.J. Hobbs), pp. 33-49 , Island Press, Washington, D.C. White, P.S. & Jentsch, A. 2001. The search for generality in studies of disturbance and 9 ecosystem dynamics. Progress in Botany, 62, 399-450 Whiting, G.J., & Chanton, J.P., 2001. Greenhouse carbon balance of wetlands: methane emissions versus carbon sequestration. Tellus Series B-Chemical and Physical Meteorology 53, 521-528. Yvon-Durocher, G., Montoya, J.M., Woodward, G., Jones, J.I., & Trimmer, M., 2011. Warming increases the proportion of primary production emitted as methane from freshwater mesocosms. Global Change Biology 17, 1225-1234. 10 Chapter 2: Structural and functional vegetation development in created and restored wetland mitigation banks of different ages1 2.1 Abstract Vegetation surveys of seven Ohio wetland sites were conducted from 2008 to 2010 during peak biomass (August). These seven sites included five created/restored mitigation bank wetlands, a created riverine research wetland, and a natural reference wetland. All of the created/restored wetlands ranged in age from 3 to 18 years. The objective of this study was to examine the development of vegetation structure and function of mitigation bank wetlands less then 20 years of age and to compare these to reference wetlands. Vegetation structure examined included species richness, floristic quality assessment index (FQAI), Shannon–Wiener diversity index (H), and community diversity index (CDI). Functional attributes included aboveground net primary productivity (ANPP) and functional group composition of dominant species. For both structure and function, the reference wetlands were statistically different from the wetland mitigation bank sites (P < 0.001, MANOVA). Structurally, there were significant differences of FQAI score (P < 0.05) and species richness (P < 0.05) with age in the mitigation sites. Functionally, there was a significant difference between ANPP (P < 0.05) and age in the mitigation sites. Over the different types of wetlands, the reference 1 Stefanik, K.C., & Mitsch, W.J. 2012. Structural and functional vegetation development in created and restored wetland mitigation banks of different ages. Ecological Engineering 39, 104-112. 11 wetlands had significantly different ANPP, FQAI scores, and species richness than did the mitigation sites (P < 0.001, P < 0.05, and P < 0.001, respectively). CDI and H were not statistically different between mitigation sites and the reference wetlands. ANPP, FQAI, and species richness tended to be higher in the reference sites than in the mitigation sites. Overall, the mitigation bank wetlands were not statistically similar to the reference sites. Within the mitigation banks, the younger sites had higher values for structural attributes than the older mitigation sites. 2.2 Introduction Throughout much of the United States, there has been a significant loss of natural wetlands since European settlement. Most of the Upper Midwestern states have lost more than 80% of their wetlands, while Ohio has lost approximately 90% of its natural wetlands since the 18th century (Dahl 1990). One way to combat further loss has been through wetland mitigation. Under Section 404 of the U.S. Clean Water Act, a permit is required to drain, damage, or destroy a jurisdictional wetland (legally recognized wetland as determined by the Wetland Delineation Manual published by the Army Corps of Engineers) (Mitsch and Gosselink 2007; Salzman and Thompson 2007). The permit holder is then required to mitigate the loss of the wetlands that were damaged or destroyed, usually at a ratio greater than 1:1, i.e. where more wetland area is created or restored than was lost. The purpose of a greater than 1:1 ratio is to avoid a net loss of wetland area and ecosystem processes. Mitigation can be done on an individual basis or by an organization that specializes in wetland creation and 12 restoration. The second type of mitigation, often referred to as a wetland mitigation bank, is when wetlands are created or restored without regard to a specific permit prior to wetland destruction. Wetland area credits from mitigation banks are then sold to permit holders to fulfill their permit requirements (Mitsch and Gosselink 2007). Ideally, the design of a created or restored wetland should be modeled after the natural wetland that was damaged or destroyed in order to replicate the wetland type and ecosystem processes of the natural site. In many cases, particularly with mitigation bank wetlands, information regarding the natural wetland that was damaged or destroyed cannot be used in the planning of the mitigation wetland. Instead, reference wetlands located near the mitigation site are used as a guide for mitigation construction and monitoring (LePage 2011). The use of high quality reference wetlands can illustrate the overall gain or loss of wetland function due to mitigation and can aid in better initial construction of the mitigation wetlands (Brinson and Rheinhardt 1996). Monitoring of mitigation wetlands usually lasts for the first five years after creation/restoration, at which point the success of the wetland is determined (NRC 2001). The success and quality of these created and restored wetlands are determined using hydrologic, vegetation, and soil characteristics, with emphasis being placed on vegetation (NRC 2001; Spieles et al. 2006). Vegetation parameters commonly used are structural in nature and include such things as species richness, percent ground cover, and percent native plant species. There is some debate as to whether or not current structural parameters are adequate for determining success. It has been suggested that structural parameters have been chosen for speed and cost efficiency and may not reflect ecological 13 processes (Mitsch and Wilson 1996; Spieles 2005; Ahn and Dee 2011). Tilman et al. (1997) found that in grassland ecosystems, functional characteristics (e.g. productivity and functional group composition) are better determinants of ecosystem processes (e.g. photosynthesis, nutrient cycling) than structural characteristics (e.g. species richness, percent cover). Another issue of concern is the 5-year monitoring period. It has been suggested that 15–20 years of maturation may be necessary before the true success of a wetland can be assessed (Mitsch and Wilson 1996). Even more time may be needed if the desired result is a forested wetland (Niswander and Mitsch 1995; NRC 2001). From a regulatory standpoint, some studies have shown poor wetland structure and function in created and restored mitigation wetlands within the desired time frame of 5 years. Success rate, described as the ability of a site to meet regulatory permit requirements within the allotted monitoring time, range from approximately 40 to 60% in some states (Cole and Shafer 2002; Reiss et al. 2009). While regulatory success is not the equivalent of ecological success (ability of a mitigation wetland to function as does a natural wetland; see Mitsch and Wilson 1996), the inability of wetlands to meet permit requirements suggests that mitigation wetlands may not adequately be capturing the ecological processes that were lost during the destruction of natural wetlands or not all wetland ecosystems are capable of achieving ecological success within a 5-year time frame. Atkinson et al. (2005) found that mitigation wetlands, after 20 years, began to reach a state of equilibrium. Additional studies have seen a similar trend, with mitigation wetland vegetation beginning to resemble vegetation of natural wetlands within approximately 20 14 years (Balcombe et al. 2005; Spieles 2005; Gutrich et al. 2009). Much of the mitigation banking within the U.S. relies on creation, restoration, and conservation techniques. Wetland creation tends to have a fairly low rate of success compared to restoration of a site, while conservation does not add any addition wetland area or replace lost ecosystem functions (ELI 2002; Spieles 2005). Construction techniques have been linked to problems with wetland development due to such things as improper placement within the landscape and soil removal/compaction by earth moving equipment (Mitsch and Wilson 1996; Campbell et al. 2002; Bruland and Richardson 2005; Bantilan-Smith et al. 2009; van der Valk et al. 2009; Ahn and Dee 2011). Wetland development can be impaired if the wetland is constructed in an area where proper hydrology cannot be obtained or if the wetland lacks connectivity to propagule sources (Mitsch and Wilson 1996; van der Valk et al. 2009). Soil removal to form wetland basins, as well as soil compaction, can alter the organic matter content and bulk density of the soil. These changes in soil characteristics can inhibit the penetration of roots within the soil and reduce nutrient availability, thus hindering the establishment of desired plant species and primary productivity (Campbell et al. 2002; Bruland and Richardson 2005; Bantilan-Smith et al. 2009; Ahn and Dee 2011). Delays in wetland development due to construction techniques may account for the inability of some mitigation projects to achieve both legal and ecological success within the allotted monitoring period. The goal of this project was to examine vegetation of created/restored mitigation bank wetlands from both a structural and functional standpoint and to compare these mitigation bank wetlands to well-maintained research wetlands of a similar age and a 15 natural reference wetland. It was hypothesized that (1) structural and functional parameters will differ between the natural/research reference wetlands and mitigation bank wetlands; (2) older wetlands will have higher productivity, species richness, and diversity than younger wetlands due to additional development time; (3) productivity in wetlands will vary based on location within Ohio due to differences in climate and ecoregion location; and (4) flow-through wetlands will have higher primary productivity and species richness resulting from the continual input of propagules into the system via surface water flow. 2.3 Methods 2.3.1 Study Site Samples were collected at seven wetland sites throughout northern and central Ohio. Three of the wetland sites are located in northern Ohio (Erie/Ontario drift lake plain ecoregion), while the remaining four sites are located in central Ohio (Eastern cornbelt plain ecoregion) (Fig. 2.1). The five mitigation bank sites used in this study are Hebron, Sandy Ridge, Slate Run, Trumbull Creek Phase I, and Trumbull Creek Phase II. The reference wetlands used included the created experimental wetlands at the Olentangy River Wetland Research Park (ORWRP) and Calamus Swamp, a natural wetland in southern Ohio owned by the Columbus Chapter of the Audubon Society (Appendix A). Not only did we want to compare the mitigation sites to a natural reference wetland, we also wanted to compare the mitigation sites to a successful created wetland of similar age. The experimental wetlands at the ORWRP are located on the northern end of The Ohio State University Columbus campus along the Olentangy River. These wetlands, created 16 in 1994, were shown more than a decade earlier (1998) to be comparable to natural wetlands in Ohio based on FQAI scores (structure) and Ohio Wetland Assessment Method ratings (function) (Elifritz and Fennessy 1999). The wetlands at the ORWRP developed quickly due to their optimum hydroperiod, hydrologic connection to the Olentangy River which acts as a propagule source for the wetlands, and continual exchange of biotic and abiotic factors with the surrounding environment (Mitsch et al. 1998, 2005a,b, 2012; Mitsch and Gosselink 2007). All of the created and restored sites contain multiple wetlands with emergent marsh vegetation and are less than 20 years in age (Table 2.1). The natural reference wetland is a marsh that is beginning a transition along the boarder into a shrub/scrub wetland dominated by Cephalanthus occidentalis. Hydrologic conditions varied from site to site and were put into one of three categories; continuously flooded, high spring low fall, and pulsing (Table 2.1). 2.3.2 Sampling Methods Sampling was performed at each of the sites in August of 2008, 2009 and 2010. Across the seven sites, 250 vegetation plots were sampled in a total of 52 wetland basins. The number of basins examined per site varied based on the overall size of the site, as well as the size of the individual wetland basins present to ensure similarities in overall area and number of sample plots examined at each site. A basin is defined as a depression within the landscape that meets the criteria of a wetland (proper hydrology, wetland vegetation, and hydric soils) and is hydrologically isolated except under major storm events. A 0.25 m2 portable pvc sampling frame was placed in the vegetation plots every 17 40 paces (approximately 0.5 m per pace) along transects established in each plant community. Plant communities were determined using visual observation and were based on the dominant species present in the community. Data collected at the plots included species present, stem density and average height for each species. These data were used to determine aboveground net primary productivity (ANPP) via regression equations. Data collected from the entire site included area of major plant communities and maximum water depth. The collected data was used to calculate species richness, Ohio floristic quality assessment index (FQAI), Shannon–Wiener diversity index (H'), community diversity index (CDI), and functional group composition of major plant communities. Additional information on site characteristics was obtained from monitoring reports and previous studies. Area of each major plant community, as well as total area of emergent vegetation was determined by ground-truthing and GPS. A Thales MoblileMapper GPS unit was used to find the area of each plant community and area of open water within each wetland. Data collected was used to determine overall area of the wetlands sampled at each site, to create vegetation maps, and to calculate CDI for each basin. Elevation maps from the mitigation monitoring reports were used to find the approximate location of lowest elevation each wetland. A weighted measuring tape was used to estimate the depth of the water at this location during each sampling visit. 2.3.3 Structural Parameters FQAI scores were calculated using the methods outlined in Andreas et al. (2004): FQAI= ∑ (CofC i ) / √( N ) 18 where C of Ci is the coefficient of conservatism for each species and N is the number of native species. All species were assigned a coefficient of conservatism value between 0 and 10 which is “an ordinal weighting factor of the degree of conservatism (or fidelity) displayed by that species in relation to all other species of the region” that was determined by Andreas et al. (2004) to be used within the state of Ohio. Species with lower coefficient of conservatism values are found in highly disturbed areas, whereas higher values are indicative of species that have a relatively narrow ecological niche (Lopez and Fennessy 2002; Ahn and Dee 2011). This system does not give additional weight to endangered or rare species. Within wetland sites of Ohio, the FQAI scores for emergent marshes tend to be around 20 or 21, with a range of approximately 11–34 (Lopez and Fennessy 2002; Andreas et al. 2004). The Shannon–Wiener diversity index (H')was also used to examine species richness and evenness between the different wetland sites: H'=−∑ ( pi ln pi ) where H is the diversity index score, s is the number of species, and p is the relative abundance of a particular species (McCune and Grace 2002). Unlike the FQAI, the H' includes non-native and invasive species in the calculations and does not include a system to give additional weight to particular species. The community diversity index (CDI; Mitsch et al. 2005a,b) was calculated using the equation: CDI=− ∑ (C i ln Ci ) where N is the number of wetland communities and C is the relative area of each wetland 19 community. This CDI is a landscape index that estimated the richness and evenness of spatial patterns of vegetation communities, using the area of communities rather than stem counts as the dependent variables. A CDI value of 0.0 represents a monospecific landscapes, whereas higher numbers indicate diverse patterns of several communities. 2.3.4 Functional Parameters Emergent macrophyte above ground net primary productivity (ANPP) was estimated from peak biomass measurements in August each year with non-destructive sampling techniques for the five mitigation bank sites and the natural wetland site (Thursby et al. 2002). Regression equations from other studies in Ohio (Johnson 1998) and the United States (Muzika et al. 1987) were used to estimate biomass for most macrophyte species. When equations were not available for a particular species, multiple biomass samples were collected for that species and dried at 105 ◦ C for 48 h. Relationship between biomass dry weight and stem height and stem density were then used to create regression equations for those species (Appendix B). Plot primary productivity data were then averaged to estimate ANPP of each wetland basin. ANPP was weighted based on area of the plant communities within the emergent zone using the equation: WANPP= ∑ ( A i Bi )/ E where WANPP is the weighted aboveground net primary productivity, A is the area of a specific community, B is the average biomass for that specific community, and E is the total area of all emergent plant communities within the wetland basin. In addition to ANPP, ANPP of emergent vegetation across the entire wetland area was determined, 20 taking into account the amount of open water at each wetland. In rare instances when no equation was available for a plant species, the plot that the species was present in was omitted from calculations and statistics regarding net primary productivity. Data collected from the omitted plots were still used for species richness, FQAI scores, and other appropriate variables. Destructive primary productivity sampling was used at the ORWRP. Vegetation samples were harvested from within a 0.5 m2 frame at ground level from 24 plots. Wet weight was determined in the lab shortly after harvesting. Harvested biomass was then separated by species and dried at 105 ◦ C for 48 h or until constant weight. For species that occurred in both the ORWRP and at least one of the mitigation sites, the regression equations used for determining primary productivity for non-destructive methods were checked for accuracy using the data collected at the ORWRP. The dominant species at each wetland site were categorized into three functional groups based on Boutin and Keddy’s (1993) functional classification of wetland plants. These groups were ruderals, interstitial and matrix species. Ruderals consist of obligate and facultative annuals, interstitial included reeds, clonal plants , and tussocks, while matrix species were clonal stress-tolerators and clonal dominants. Highly disturbed sites tend to be dominated by ruderals, whereas natural wetlands are dominated by matrix species (Matthews and Endress 2010). 2.3.5 Statistical Methods Multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA) were used to test hypotheses. To avoid problems with pseudoreplication due to small 21 wetland size and proximity of the wetlands across the sites, data for the wetlands at Trumbull Creek Phase II South, as well as Trumbull Creek Phase II North were combined to obtain one value for each parameter at these sites. This reduced the data set from 52 to 13 wetland basins. The statistical software program R was used to test assumptions and perform the MANOVA and ANOVA tests (determined assumptions were met using D’agostino skewness test, Anscomb–Glynn kurtosis test, Shapiro–Wilks normality test all at ST = 0.1, normal quantile–quantile plots, and scatter plots) (The R Foundation for Statistical Computing 2009). Linear regression analysis was then preformed to determine the type of relationship (positive or negative) between the structural and functional parameters and age of the mitigation sites. Statistical tables can be found in Appendix F. A detrended canonical correspondence analysis (DCCA) was preformed to determine the type of analysis, canonical correspondence analysis or redundancy analysis (CCA and RDA, respectively), to be used for the data set. A gradient length of 2.52 was obtained for the first axis. Since the gradient length is less than three, using the suggestion from Leps and Smilauer (2003), a redundancy analysis (RDA) was used to analyze patterns in the data. A Monte Carlo test was preformed to test the null hypothesis that the species data are independent from the environmental variables. The computer software CANOCO was used for DCCA, RDA, and the Monte Carlo test (ter Braak and Smilauer 2004). The DCCA, as well as the RDA, were performed on species presence/absence data and environmental data for the sites. Categorical environmental variable for type of hydrology and location/ecoregion in Ohio were turned into dummy variables. All of the continuous environmental variables were standardized since they 22 were on different scales. 2.4 Results 2.4.1 Structural and Functional Parameters Species richness was highest at the reference research site (98 species), Sandy Ridge (102 species), and Trumbull Creek Phase I (109 species). The wetland sites had 2– 9 dominant species and 2–13 identifiable plant communities. The Hebron site had the lowest number of dominant species and communities while the Sandy Ridge site had the highest number of dominant species and number of plant communities. FQAI scores for the wetlands ranged from 13.5 to 29.5 at the mitigation banks, 19.9 to 23.8 at the research site, and 26.9 at the natural wetland. The macrophyte H' ranged from 0.51 to 1.90 at the mitigation bank wetlands and was 1.75 at the natural reference wetland. The CDI ranged from 0.90 to 1.75 for the mitigation sites and from 0.84 to 1.44 for the reference sites (Table 2.2) (Appendix C). Water depth varied greatly from site to site. Trumbull Creek Phase I North, Sandy Ridge, and two wetlands at Slate Run had more than 1 m of standing water during August and September sampling, whereas many of the wetlands within Trumbull Creek Phase II North and Trumbull Creek Phase II South had no standing water at the time of sampling. The wetlands at Hebron, ORWRP, Calamus Swamp, and the two remaining wetlands at Slate Run had water depths between 10 and 100 cm. Area of emergent vegetation was largest at Sandy Ridge (7.6 ha) and smallest at Trumbull Creek Phase II North (0.23 ha). Hebron and Trumbull Creek Phase I wetlands had the most area of emergent vegetation, while ORWRP, Slate Run, and Trumbull Creek Phase II South had the least. 23 WANPP ranged from 201 to 802 g DW m−2 yr−1 at the mitigation bank sites, 529 to 866 g DW m−2 yr−1 at the research reference wetlands and 1093 g DW m−2 yr−1 at the natural reference wetland (Table 2.2). For functional groupings of the dominant species at each site, the reference wetlands had 84–100% matrix species (Table 2.3). The remaining dominant species in the reference wetlands were in the interstitial group. In the oldest mitigation bank site (Hebron), matrix species accounted for 57% of the dominant species, while ruderals were 29%. The second oldest mitigation bank site had 20% matrix species and 40% ruderals (Sandy Ridge). The intermediate age wetland had 45% matrix species and 36% ruderals. The two youngest mitigation bank sites had the lowest percentage of matrix species (29–30%). Of all of the sites, the two youngest mitigation banks had the highest amount of interstitial species (50–57%). 2.4.2 Hypotheses Testing MANOVA was preformed for the four different hypotheses. P-values of ≤0.05 were found for comparisons of mitigation vs. reference wetlands (MANOVA p=0.003, F=4.8516, df=5,31), age (MANOVA p=0.001, F=1.887, df=75,105), location in Ohio (MANOVA p<0.001, F=10.924, df=5,31), and hydrology (MANOVA p<0.001, F=4.153, df=10,62) for the structural and functional parameters examined. Year sampled had no effect on any of the dependent variables (MANOVA p=0.407, F=1.8503, df=5,31). ANOVA was then used to assess the significance of these environmental variables on the structural and functional vegetation characteristics (Table 2.2). Significant differences were found between age and WANPP (ANOVA p=0.006, F=8.705, df=1,28) log ANPP over the entire wetland (ANOVA p<0.001, F=14.374, df=1,28), FQAI score (ANOVA 24 p=0.005, F=9.218, df=1,28), and species richness (ANOVA p=0.033, F=5.031, df=1,28). Linear regression analysis was used to determine the type of relationship, positive or negative, between the significant vegetation variables and age of the mitigation sites. A positive relationship was found between age and WANPP (Fig. 2.2). Negative relationships were found between age and FQAI sores and species richness (Fig. 2.2). Log ANPP over the entire wetland did not exhibit a linear pattern, but had higher values in the younger and older mitigation sites (Fig. 2.2). Significant differences were found between type of hydrology and WANPP (ANOVA p=0.026, F=4.005, df=2,34), FQAI score (ANOVA p=0.020, F=4.399, df=2,34), and species richness (ANOVA p< 0.001, F=16.11, df=2,34). Pulsed hydrology wetlands had the highest WANPP, with high spring low fall wetlands having the lowest. Continuously flooded wetlands had some of the highest FQAI scores, whereas high spring, low fall wetlands had some of the lowest scores. Continuously flooded wetlands had the largest range of species richness across sites, while pulsed wetlands had all higher values of species richness. Additionally, significant differences were found between location in Ohio and FQAI scores (ANOVA p<0.001, F=14.28, df=1,35), number of communities (ANOVA p<0.001, F=29.04, df=1,35), species richness (ANOVA p=0.011, F=7.151, df=1,35), and CDI (ANOVA p=0.02, F=5.942, df=1,35). Overall, wetlands located in the northern portion of Ohio had higher FQAI scores, number of communities, and species richness. Finally, significant differences were found between the type of wetland (mitigation vs. reference) and WANPP (ANOVA p<0.001, F=18.63, df=1,35), log ANPP over the entire wetland (ANOVA p=0.013, F=6.864, df=1,35), FQAI score (ANOVA p=0.042, F=4.451, 25 df=1,35), and species richness (ANOVA p<0.001, F=20.33, df=1,35). WANPP, log ANPP over entire wetland, FQAI scores and species richness tended to be higher in the natural and research wetlands than wetlands created for mitigation. There was no statistical difference between mitigation reference wetlands in terms of number of communities present, H, and CDI. While, on average, the mitigation wetlands had lower WANPP, FQAI, species richness, and number of dominant communities, two of the mitigation sites in northern Ohio (Sandy Ridge and Trumbull Creek Phase I) had species richness, FQAI scores, and number of dominant plant communities similar to those found in the reference wetlands . 2.4.3 Redundancy Analysis The Monte Carlo test found P = 0.002 for the first two canonical axes. This suggests that species data are not independent of the environmental variables. For the RDA, the first four axes explained less than 10% of the total variance. Only species with greater than 20% dominance are displayed on the triplot. From the triplot (Fig. 2.3), the sites separated out with plots from Trumbull Creek Phase 1 and Sandy Ridge on the right hand side of the graph and Hebron, Slate Run, Trumbull Creek Phase 2 South, Trumbull Creek Phase 2 North, ORWRP, and Calamus Swamp on the right hand side of the graph. Area of emergent vegetation was highest in Sandy Ridge and Trumbull Creek Phase I. These two sites also had the largest total area and deepest standing water depths. Species common to these sites were Juncus effuses, Polygonum hydropiperoides, Scirpus cyperinus, Sparganium americanum, Bidens cernua, and Polygonum hydropiper. The youngest site, Trumbull Creek Phase II N seems to be following a similar path as Hebron, 26 the oldest mitigation site. The other side of the youngest site, Trumbull Creek Phase II S seems to be developing along a similar trajectory as Calamus Swamp, the natural reference wetland, based on environmental variables and dominant species at both sites. Vegetation typical of these sites includes Typha spp., Cyperus esculentus, and Scirpus cyperinus. The ORWRP is somewhat similar to Hebron, Calamus Swamp, and both Trumbull Creek Phase II sites. Vegetation characteristic of the ORWRP include Typha spp. and Sparganium eurycarpum. Slate Run seems to be the most unlike the other sites. Species common here include Scirpus pungens, Leersia oryzoides, Cyperus strigosus, and Ludwigia palustris. 2.5 Discussion 2.5.1 Structure Within the mitigation bank wetlands, the vegetation structural characteristics (species richness, FQAI) of the younger sites were similar to the natural and created reference wetlands. The older sites, however, tended to have lower species richness and FQAI than the younger sites. The number of communities, CDI, and H' for all mitigation wetlands was similar to the reference sites. Other studies have found that mitigation wetlands tend to have high species richness during the monitoring period, but species richness begins to decline with age (Fennessey and Roehrs 1997; Campbell et al. 2002; Balcombe et al. 2005; Gutrich et al. 2009) and that indicators based on species composition were high shortly after wetland creation, but decreased over time (Matthews 2008). Data suggests this is occurring along the time gradient in the mitigation bank wetlands used for this study. Caution should be taken when examining multiple sites 27 along a time gradient due to variation in construction techniques and goals. Decreases in species richness and associated parameters with age of the mitigation wetlands are likely due to disturbance and successional processes occurring after creation and restoration. Creation and restoration techniques are major disturbances at the sites. With wetland creation, the ecosystem begins after a large disturbed, with little to no species present. Succession of vegetation, driven by both biotic and abiotic factors (competitive exclusion, plant-soil feedback, nutrient input to the system, weather, climate, and disturbance), results in changes to the structural characteristics of the ecosystem. Changes in biotic process, such as primary productivity can greatly influence an ecosystem. Studies have shown that low and high productivity sites tend to have low species richness, while intermediately productive sites had the highest species richness (Grime 1979; Tilman 1986). Examining the mitigation bank sites over a time gradient, changes in the biotic and abiotic processes at the sites are likely responsible for the decline in structural characteristics. Results from this study suggests that peak species richness occurs somewhere between the 4- and 7-year mark after wetland creation. This could be problematic when determining the success of a mitigation bank wetland since many parameters rely on structural vegetation characteristics and monitoring tends to only last 5 years. Since peak species richness seemed to occur between the 4- and 7-year mark, monitoring time frames of at least 10 years may be more appropriate to capture declines in structural characteristics after the initial peak than current monitoring time frames. As far as these study sites are concerned, additional monitoring is needed to determine what 28 changes, if any, there will be in species richness and related parameters but, since the two mitigation sites are currently higher than the reference wetlands the values may stabilize near those found in the reference sites. FQAI scores at the mitigation bank sites and the reference sites fell within the range of scores (11–34) found in other studies examining marsh habitats in Ohio (Andreas et al. 2004; Lopez and Fennessy 2002). The reference wetlands tended towards the middle and top of this range while the mitigation sites fell throughout. This would suggest that Trumbull Creek Phase I is a relatively good quality wetland given its high FQAI score, whereas the older and the younger wetlands tend to be of lower quality. However, differences in wetland classification of the mitigation banks may influence the floristic quality of the site. 2.5.2 Function Within the mitigation sites, WANPP increased with age, but was significantly lower in the reference sites. Of the sites used, all of the reference sites, as well as the oldest mitigation bank (2010) had high WANPP, most likely due to the high amount of Typha spp. present in the wetlands. Primary productivity is likely dependent on the types of species present, not necessarily on the number of species present. As an example, a wetland dominated by Phragmites australis would likely have high primary productivity, but low species richness due to its tendency to form monocultures. Windham (2001) found that P. australis had a peak productivity of almost 2000 g DW m−2 yr−1 . This is approximately double what was found at the most productive site used in this study. Since high ANPP is typical of marshes dominated by Typha spp. and invasive species, 29 high ANPP at a mitigation site may not be desirable considering monitoring goals that in some cases call for less than 5% invasive species at the sites (Davey 2007a,b). On the other end of the spectrum, low ANPP is not necessarily desirable since improper hydrology can result in low plant survivorship and thus low NPP (Fraser and Karnezis 2005). Thus the current amount of ANPP, especially at the middle age range, of the mitigation banks may be desirable. Functional groups of the dominant species tended towards matrix species as age of the wetland increased. Newly created wetlands, where no or minimal planting has occurred tend to see a successional pattern where ruderals or annual species are the first to dominate at the site. These ruderal species eventually give way to the perennial interstitial and matrix species (Matthews and Endress 2010). This pattern of succession can be seen across the mitigation bank wetlands with the older wetlands having a mix of ruderals, interstitial, and matrix species, and the younger sites have a higher percentage of interstitial species than matrix. This suggests that all of the mitigation sites are still maturing functionally, but that the older the sites are the closer the functional groups of the dominant species resemble the reference wetlands. This is not surprising given that other studies have found that at about the 20-year mark, mitigation wetlands were reaching a state of vegetation equilibrium and that vegetation in mitigation wetlands was similar to natural reference wetlands (Atkinson et al. 2005; Balcombe et al. 2005; Gutrich et al. 2009; Spieles 2005). 2.5.3 Mitigation Bank and Reference Wetlands Comparison Looking at a direct comparison of function to structure, in this case productivity 30 to diversity, the reference sites were high productivity, high diversity wetlands in comparison to the sites used in this study (Fig. 2.4). Of the mitigation sites examined, Trumbull Creek Phase I site was also a high productivity, high diversity wetland. Sandy Ridge and Trumbull Creek Phase II tended to be high diversity, low productivity wetlands, while Hebron and Slate Run were mainly low diversity, low productivity wetlands. Trumbull Creek Phase I most resembles the reference wetlands used in this study. Some studies examining the relationship of species richness to productivity in plants have found that both low and high productivity sites tend to have low species richness, while intermediate productivity sites had the highest species richness (Grime 1979; Tilman 1986). Of the sites in this study, the ORW, Trumbull Creek Phase I, and Sandy Ridge fall somewhere in this intermediary productivity range and thus have the highest diversity of the sites. ANPP at these three sites falls within the range of approximately 450–750 g DW m−2 yr−1 when weighted by community area within the zone of emergent vegetation. Based on the findings of this study regarding ANPP and species richness, diversity is highest under median levels of ANPP, which could be useful in the regulation process when determining target goals in created freshwater marshes to allow for optimum productivity and diversity at the sites. The younger mitigation banks are structurally more similar to the reference wetlands than are the older mitigation banks. This may be due to better initial construction techniques of the newer sites. The younger sites had more detailed and better developed goals than the older sites (such as specifics about water depths, allowable % invasive species cover, % cover of specific wetland habitat/wetland communities, and 31 types of specific wetland habitat) (Davey 2007c), probably due to a combination of learning on the part of the mitigation bank creator, as well as stricter requirement established for wetland mitigation. From a functional standpoint, none of the mitigation sites were statistically similar to the reference sites, but the older mitigation sites were more similar than the younger sites. This suggests that the sites are heading towards functional similarity with the reference wetlands and may need more time to mature before determining functional success. It is important to take into account the fact that the wetlands examined in this study were located in different ecoregions of the state of Ohio and fell in different hydrogeomorphic classifications. It is possible that these differences may have influenced the structural and functional characteristics of the sites. However, there is some difficulty in finding mitigation bank wetlands created by the same company (which may aid in reducing large differences associated with construction) along the desired time gradient, in the same ecoregion, and of the same wetland type. A large-scale study including multiple wetlands in each ecoregion and of each hydrogeomorphic classification along the desired time gradient with multiple reference wetland in each ecoregion and hydrogeomorphic classification would likely reduce the influence of location and classification. 2.6 Conclusions The younger mitigation sites were structurally similar to the reference wetlands while none of the mitigation sites were quite on the same level functionally as the reference sites. Only time will tell if these younger wetlands will remain structurally 32 similar to the reference wetlands and if the mitigation sites will develop functional characteristics similar to those of the reference wetlands. Based on the results of this study, there are three recommendations for improving the restoration/creation and monitoring practices of mitigation bank wetlands: • Extend monitoring to at least 10–15 years after creation to allow the structural characteristics of the wetland to stabilize before determining if the mitigation project was a success. • Monitor trends in the succession of functional groups to help determine if the mitigation wetlands are functionally equivalent to natural wetlands. • Aim for median levels of ANPP within emergent zones for enhanced diversity. The use of non-destructive ANPP and functional group classifications as monitoring tools requires little additional time in the field and can be derived mainly from currently assessed structural parameters, particularly when regression equations for biomass determination have already been established. Additional research is needed to examine more in-depth the roles of individual species within these sites as well as the environmental variables likely associated with the specific plant assemblages at each site and how this may influence the success of a mitigation project. 2.7 References Acton, W.T., 2004. A Monitoring and Management Report Year Four for the Ohio Wetland Foundation Wetland Mitigation Bank at the Slate Run Metropark Pick- 33 away County, Ohio. Geotechnical Consultants Inc., Westerville, OH. Ahn, C., & Dee, S., 2011. Early development of plant community in a created mitigation wetland as affected by introduced hydrologic design elements. Ecological Engineering 37, 1324–1333. Andreas, B.K., Mack, J.J., & McCormac, J.S., 2004. Floristic Quality Assessment Index (FQAI) for Vascular Plants and Mosses for the State of Ohio. Ohio Environmental Protection Agency, Division of Surface Water, Wetland Ecology Group, Columbus, OH, 219 pp. Atkinson, R.B., Perry, J.E., & Cairns Jr., J., 2005. Vegetation communities of 20-year-old created depressional wetlands. Wetland Ecology and Management 13, 469–478. Balcombe, C.K., Anderson, J.T., Fortney, R.H., Rentch, J.S., Grafton, W.M., & Kordek, W.S., 2005. A comparison of plant communities in mitigation and reference wetlands in the Mid Appalachians. Wetlands 25, 130–142. Bantilan-Smith, M., Bruland, G.L., MacKenzie, R.A., Henry, A.R., & Ryder, C.R., 2009. A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai’i. Wetlands 29, 1023–1035. Boutin, C., & Keddy, P.A., 1993. A functional classification of wetland plants. Journal of Vegetation Science 4, 591–600. Brinson, M.M.,1993. A hydrogeomorphic classification for wetlands. In: Technical Report WRP-DE-4. U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS. Brinson, M.M., & Rheinhardt, R., 1996. The role of reference wetlands in functional 34 assessment and mitigation. Ecological Applications 6, 69–76. Bruland, G.L., & Richardson, C.J., 2005. Spatial variability of soil properties in created, restored, and paired natural wetlands. Soil Science Society of America Journal 69, 273–284. Campbell, D.A., Cole, C.A., & Brooks, R.P., 2002. A comparison of created and natural wetlands in Pennsylvania, USA. Wetland Ecology and Management 10, 41–49. Cole, C.A., & Shafer, D., 2002. Section 404 wetland mitigation and permit success criteria in Pennsylvania, USA, 1986–1999. Environmental Management 30, 508– 515. Dahl, T.E., 1990. Wetlands Losses in the United States 1780s to 1980s. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC, l3 pp. Davey Resource Group, 2007a. Monitoring and Management Report, Sandy Ridge Wetlands Mitigation Bank, North Ridgeville, Ohio. Davey Resource Group, Kent, OH. Davey Resource Group, 2007b. Year Two Wetlands Monitoring and Management Report, Trumbull Creek Wetlands Mitigation Bank Phase 2 North and South, Thompson Township Geauga County and Trumbull Township Ashtabula County, Ohio. Davey Resource Group, Kent, OH. Davey Resource Group, 2007c. Year Five Monitoring and Management Report Trumbull Creek Wetlands Mitigation Bank Phase 1, Thompson Township Geauga Count and Trumbull Township Ashtabula County. Davey Resource Group, Kent, Ohio. 35 Elifritz, B.F., & Fennessy, M.S.,1999. A comparison of natural and constructed wetlands using the floristic quality assessment index. In: Olentangy River Wetland Research Park Annual Report 1998. The Ohio State University, Columbus, pp. 69–73. Environmental Law Institute, 2002. July. Banks and Fees: The Status of Off-site Wetland Mitigation in the United States. Washington, DC, Environmental Law Institute, www.eli.org/Program Areas/WMB. Fennessey, S., & Roehrs, J., 1997. A Functional Assessment of Mitigation Wetlands in Ohio: Comparisons With Natural Systems. Ohio Environmental Protection Agency Division of Surface Waters, Columbus, OH. Fraser, L.H., & Karnezis, J.P., 2005. A comparative assessment of seedling survival and biomass accumulation for fourteen wetland plant species grown under minor water-depth differences. Wetlands 25, 520–530. Grime, J.P., 1979. Plant Strategies and Vegetation Processes. John Wiley and Sons, New York, NY. Gutrich, J.J., Taylor, K.J., & Fennessy, M.S., 2009. Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): the importance of initial effort for mitigation success. Ecological Engineering 35, 351–368. Johnson, S.A., 1998. Effects of hydrology and plant introduction techniques on firstyear macrophyte growth in a newly created wetland. Thesis. The Ohio State University, Columbus, OH. 36 Keddy, P., Fraser, L.H., & Wisheu, I.C., 1998. A comparative approach to examine competitive response of 48 wetland plant species. Journal of Vegetation Science 9, 777–786. Lenssen, J., Menting, F., van der Putten, W., & Blom, K., 1999. Control of plant species richness and zonation of functional groups along a freshwater flooding gradient. Oikos 86, 523–534. LePage, B.A., 2011. Wetlands: A Multidisciplinary Perspective. Springer, Netherlands. Leps, J., & Smilauer, P., 2003. Multivariate Analysis of Ecological Data using CANOCO. Cambridge University Press, Cambridge, United Kingdom. Lopez, R.D., & Fennessy, M.S., 2002. Testing the floristic quality assessment index as an indicator of wetland condition. Ecological Applications 12, 487–497. Matthews, J.W., 2008. Restoration progress and plant community development in compensatory mitigation wetlands. Dissertation Abstracts International. 69, 272. Matthews, J.W., & Endress, A.G., 2010. Rate of succession in restored wetlands and the role of site context. Applied Vegetation Science 13, 346–355. McCune, B., & Grace, J.B., 2002. Analysis of Ecological Communities. MJM Software Design, Glenedon Beach, OR. Mitsch, W.J., & Wilson, R.F., 1996. Improving the success of wetland creation and restoration with know-how, time, and self-design. Ecological Applications 6, 77– 83. Mitsch, W.J., Wu, X., Nairn, R.W., Weihe, P.E., Wang, N., Deal, R., & Boucher, C.E., 37 1998. Creating and restoring wetlands: a whole-ecosystem experiment in selfdesign. BioScience 48, 1019–1030. Mitsch, W.J., Wang, N., Zhang, L., Deal, R., Wu, X., & Zuwerink, A., 2005a. Using ecological indicators in a whole-ecosystem wetland experiment. In: Handbook of Ecological Indicators for Assessment of Ecosystem Health. CRC Press, Boca Raton, FL, pp. 211–236. Mitsch, W.J., Zhang, L., Anderson, C.J., Altor, A., & Hernandez, M., 2005b. Creating riverine wetlands: ecological succession, nutrient retention, and pulsing effects. Ecological Engineering 25, 510–527. Mitsch, W.J., & Gosselink, J.G., 2007. Wetlands, 4th ed. John Wiley & Sons, Inc., Hoboken, NJ. Mitsch, W.J., Zhang, L., Stefanik, K.C., Nahlik, A.M., Anderson, C.J., Bernal, B., Hernandez, M., & Song, K., 2012 Creating wetlands: primary succession, water quality changes, and self-design over 15 years. BioScience 62, 237-250. Muzika, R.M., Gladden, J.B., & Haddock, J.D., 1987. Structural and functional aspects of succession in south-eastern floodplain forests following a major disturbance. American Midland Naturalist 117, 1–9. National Research Council, 2001. Compensating for Wetland Losses under the Clean Water Act, Committee on Mitigating Wetland Losses. National Academies Press, Washington, DC. Niswander, S.F., & Mitsch, W.J., 1995. Functional analysis of a two-year-old created in-stream wetlands: hydrology, phosphorus retention, and vegetation survival 38 and growth. Wetlands 15, 212–225. The R Foundation for Statistical Computing, 2009. R Version 2.10.1 (2009-12-14). Reiss, K.C., Hernandez, E., & Brown, M.T., 2009. Evaluation of permit success in wetland mitigation banking: a Florida case study. Wetlands 29, 907–918. Salzman, J., & Thompson Jr., B.H., 2007. Environmental Law and Policy. Foundation Press, New York, NY. Spieles, D.J., 2005. Vegetation development in created, restored, and enhanced mitigation wetland banks of the United States. Wetlands 25, 51–63. Spieles, D.J., Coneybeer, M., & Horn, J., 2006. Community structure and quality after 10 years in two central Ohio mitigation bank wetlands. Environmental Management 38, 837–852. ter Braak, C.J.F., & Smilauer, P., 2004. Canoco for Windows (Version 4.53). BiometricsPlant Research International, Wageningen, Netherlands. Tilman, D., 1986. Resources, Competition, and the Dynamics of Plant Communities. Plant Ecology. Blackwell Scientific, Boston, MA. Tilman, D., Knops, J., Wedin, D., Reich, P., Ritchie, M., & Siemann, E., 1997. The influence of functional diversity and composition on ecosystem processes. Science 277, 1300–1302. Thursby, G.B., Chintala, M.M., Stetson, D., Wigand, C., & Champlin, D.M., 2002. A rapid, non destructive method for estimating aboveground biomass of salt marsh grasses. Wetlands 22, 626–630. United States Department of Agriculture Natural Resources Conservation Service.Web 39 soil survey. http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey. aspx (accessed 23.02.11). van der Valk, A.G., Toth, L.A., Gibney, E.B., Mason, D.H., & Wetzel, P.R., 2009. Potential propagule sources for reestablishing vegetation on the floodplain of the Kissimmee river, Florida, USA. Wetlands 29, 976–987. Windham, L., 2001. Comparison of biomass production and decomposition between Phragmites australis (common reed) and Spartina patens (salt hay grass) in brackish tidal marshes of New Jersey, USA. Wetlands 21, 179–188. 40 Table 2.1 Year of creation, site and wetland areas, hydrology, hydrogeomorphic classification, soil type, and location of Ohio wetland mitigation banks and reference wetlands (Acton, 2004; Brinson, 1993; Davey, 2007a,b; United States Department of Agriculture Natural Resources Conservation Service, 2011)). For hydrogeomorphic classification (HGM), the first letter is the geomorphic settings, the second letter is the water source, and third letter is the hydrodynamics. D: depressional, R: riverine, P: precipitation, S: surface flow, G: groundwater, V: vertical fluctuation, and U: unidirectional flow. All wetlands were dominated by emergent vegetation. It is unknown how long current dominant vegetation at the natural site has been occurring at this site. Hebron Year created Total site area (ha) Total area of wetlands investigated (ha) Mitigation Bank Wetlands Trumble Sandy Slate Run Creek Ridge Phase I Reference Wetlands Trumble Creek Phase 2 Calamus Swamp Olentangy Wetland Park 1992 1998 1999 2000 2005 Natural 1994 13.4 46.5 63.9 56.7 117.8 7.7 21 8.8 20.7 9.1 6.2 1.2 4.9 2 Wetland hydrology High spring low fall / Continuously flooded Continuously flooded High spring low fall Continuously flooded High spring low fall High Spring low fall Pulsing HGM classification DPV DP/SV DPV and DP/GV DPV DPV DPV RSU Dominant soil type Luray Silty Clay Loam Fitchville Silt Loam Kokomo Silty Clay Loam Platea and Sheffield Silt Loam Sheffield Silt Loam Montgomery Silty Clay Loam Ross Silt Loam Location Licking County North Ridgeville, Lorain County Pickaway County GeaugaAshtabula Counties GeaugaAshtabula Counties Circleville, Pickaway County Columbus, Franklin County 41 Table 2.2 Average ± standard error of structural and functional parameters at each wetland site. Species richness, number of communities, Ohio floristic quality assessment index (FQAI), Shannon–Wiener diversity index (H ), community diversity index (CDI), and weighted ANPP (WANPP) of all wetland sites over 2008, 2009, and 2010. Calamus Swamp data are for 2010 only. FQAI defined by Andreas et al. (2004). CDI defined by Mitsch et al. (2005a,b). Functional group ratios of ruderal:interstitial:matrix categories for the dominant species at each site were determined using Boutin and Keddy (1993), Keddy et al. (1998), and Lenssen et al. (1999). P-values were determined using ANOVA. All statically significant P-values (≤0.05) are in bold. Reference Wetlands Mitigation Bank Wetlands Hypothesis p-values Mitigation Sandy Slate Cala vs. Hydro Hebron Ridge Run TCPI TCPII -mus ORW reference Age -logy Species richness S Number of t communr ities u c t FQAI u r H e CDI F u n WANPP c t i o Functional n group ratio 44 ±2.3 44.6 88.7 68 ±2.8 ±10.5 ±4.3 87 95.5 ±1.2 <0.001 0.033 <0.00 1 0.011 11.3 5.3 8.3 7.8 ±0.88 ±0.63 ±0.33 ±0.60 7 4.8 ±0.54 0.254 0.72 0.367 <0.001 15.6 ±0.54 22.8 17.1 27.1 20.5 21.7 ±1.3 ±0.57 ±1.39 ±0.86 26.9 ±0.78 0.042 0.005 0.02 <0.001 1.20 ±0.21 1.27 1.10 1.47 1.23 ±0.27 ±0.11 ±0.19 ±0.22 1.75 0.212 0.209 0.794 0.409 1.10 ±0.13 1.01 0.77 1.28 1.45 1.34 ±0.15 ±0.09 ±0.11 ±0.14 0.84 ±0.10 0.165 0.187 0.209 0.02 <0.001 0.006 0.026 0.77 4 ±1 91 ±6.3 Location 441 ±45 663 ±16 440 ±51 na 451 ±52 452 ±44 2:1:4 2:2:1 4:2:5 1:4:2 2:5:3 0:0:4 0:1:5 42 1093 682 ±52 Table 2.3 Functional groups of dominant wetland plant species at the five mitigation sites and two reference sites. Functional groups are defined by Boutin and Keddy (1993), Keddy et al. (1998), and Lenssen et al. (1999). Mitigation Bank Wetlands Hebron R U D E R A L S Bidens cernua I N T E R S T I T I A L Alisma plantagoaquatica Sandy Ridge X Cyperus spp. Echinochloa spp. Eleocharis obtusa Polygonum pensylvanicum X X X Scirpus pungens Sparganium americanum Sparganium eurycarpum Typha spp. X X X Calamus Swamp ORW X X Leersia orizoides M Polygonum A hydropiperoides T Schenoplectus R tabernaemontani I X Scirpus fluviatilis X X X Decodon verticallus Phalaris arundinacea Phragmites australlis Reference Wetlands Trumbull Creek Phase 2 X Juncus effusus Juncus torreyi Pontederia cordata Scirpus cyperinus Slate Run X Trumbull Creek Phase 1 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 43 X Figure 2.1 Location of wetland sites within Ohio, USA. Sandy Ridge, Trumbull Creek Phase I and Trumbull Creek Phase II North and South are located in the northern portion of the state, while Hebron, Slate Run, Olentangy River Wetland Research Park (ORWRP), and Calamus Swamp are located in central Ohio. 44 Chapter 3: Vegetation productivity of riverine planted and unplanted wetlands fifteen to seventeen years after creation 3.1 Summary 1. Many created wetlands are monitored for only five years after creation before being deemed a success or failure. At the five-year mark, many wetlands are still developing and the plant assemblages may not be an accurate representation of what will be present once the ecosystem matures. Initial creation techniques, such as planting, are likely to affect vegetation structure and function over time. 2. The goal of this study was to compare macrophyte structure and function between a planted and unplanted wetland from fifteen to seventeen years after creation. 3. Samples for emergent macrophyte vegetation were collected at twenty-four 0.5 m2 plots in the two wetlands from April -September of 2008 - 2010. Transitional zone vegetation was sampled on a monthly basis from April through September of 2008 and 2009. Data collected and parameters measured included, species richness, Floristic Quality Assessment Index scores (FQAI), Community Diversity Index scores, number of macrophytes species, above and belowground net primary productivity, and macrophyte nutrient concentration. 4. The planted wetland had higher species richness and FQAI scores than the unplanted wetland. The unplanted wetland had more area occupied by invasive 48 species than the planted wetland. Community diversity and number of macrophytes were similar between wetlands. 5. Aboveground net primary productivity was higher for emergent vegetation in the unplanted wetland (796 to 866 g DW/m2 year) than the planted wetland (673 to 712 g DW/m2 year)(p=0.006). Belowground net primary productivity was similar between the two wetlands and there was no difference in total net primary productivity. 6. Within the transitional zone, there was no difference in edge herbaceous aboveground productivity, belowground productivity, woody net primary productivity or litterfall. 7. Synthesis and applications. While planting of a created riverine wetland may not be seen as being as important as planting isolated created wetland, this study did find some differences in structural and functional parameters between the planted and unplanted wetland. Planting in a riverine system may aid in reducing area occupied by invasive species, and increase species richness and floristic quality in the long term. 3.2 Introduction The act of wetland creation is a high impact disturbance of an ecosystem in which the initial creation process will likely have an effect on succession of the system. The successional trajectory, or the direction of change in vegetation over time, of a system can progress in a variety paths along a continuum from both low quality to high quality 49 ecosystems and from early successional to late successional types of vegetation (Suding and Cross 2006). Created wetland systems can be thought of as highly disturbed, low quality systems at the beginning of creation, but will develop over time, influenced by such things as position in the landscape, availability of propagules, and soil compaction at the site (Mitsch and Wilson 1996; Campbell et al. 2002; Bruland and Richardson 2005; Bantilan-Smith et al. 2009; van der Valk et al. 2009; Ahn and Dee 2011). Since the 1980s, wetland creation and restoration to mitigate the loss of natural wetlands has been a growing practice. There has been evidence that over the years the overall quality of mitigation wetlands has been increasing (NRC 2001). Unfortunately, monitoring usually occurs for the first five years after creation to determine whether or not the wetland is successful (Mitsch and Wilson 1996; NRC 2001). Once deemed successful, mitigation wetlands may be managed, but additional monitoring is unlikely. The trajectory of succession may not be fully visible after the first five years of creation (Matthews et al. 2009). Studies have shown that there tends to be an initial peak in structural parameters of a system, which then declines over time (Fennessey and Roehrs 1997; Campbell et al. 2002; Balcombe et al. 2005; Spieles 2006; Gutrich et al. 2009; Stefanik and Mitsch 2012). It is difficult to determine the exact point where this initial peak will occur, so it may be more accurate to either wait for the peak to occur before trying to predict successional trajectories or to reexamine the successional trajectory following the peak in structural parameters. Additionally, it may take a number of years for a created wetland to develop soils that are similar to natural wetlands in terms of soil organic matter, nutrient content, and seed bank, which can affect both the types of species 50 that colonize a wetland and the function of the species present (Choi 2004). Future disturbances to the system (both natural and anthropogenic) can alter successional trajectories. The frequency and severity of disturbance to a system plays a roll in the length of time spent in a particular successional stage, as well as how often ecosystems revert to early successional stages (Walker and del Moral 2008). It is also possible that disturbances to the site may not allow the vegetation to progress beyond early successional stages. Disturbances that affect dominant species instead of minor species will likely have a greater impact on the entire ecosystem than disturbance that affect minor species. If there are minor species in the ecosystem that functionally overlap the dominant species, it is possible for the ecosystem to be somewhat resilient to disturbances (White and Jentsch 2001). During creation and restoration projects, it is important to take into account that future disturbances are inevitable and steps should be taken to increase the resilience of the system. One way to increase resiliency may be to plant a wide variety of species with overlapping functional traits. Mitsch and Wilson (1996) suggested that with wetland creation and restoration, the best approach for vegetation introduction may be to introduce as many species as possible and then allow the system to self-design or allow nature to chose the species most appropriate for the system. For this study, an initial experiment was implemented in which two wetlands of equal size and hydrologic regime were constructed and one was planted, while the other was left to rely on natural colonization. The purpose of this project was to examine vegetation development, both above- and belowground, of two created riverine wetlands 51 fifteen to seventeen years after establishment to determine how the trajectories taken by both wetlands differ and to reexamine the initial experiment of planting versus not planting on the success of the two wetlands. It was hypothesized that: 1. Structural characteristics, along with functional diversity will be greater (i.e. higher diversity, species richness, floristic quality, etc.)within the planted created wetland than for an unplanted created wetland. 2. The planted created wetland will have greater total net primary productivity, aboveground net primary productivity, and belowground net primary productivity than the unplanted created wetland. 3. Initial planting efforts will effect the structural and functional characteristics of the surrounding transitional zone from wetland to upland since plant-soil feedbacks began sooner in the planted wetland, likely causing soil characteristic changes to occur sooner in the planted wetland. From this study, we have shown that planting may be beneficial even in riverine wetlands that receive frequent propagule inputs, particularly in terms of structural characteristics. 3.3 Materials and Methods 3.3.1Study Site The two experimental wetlands at the Olentangy River Wetland Research Park, Ohio State University, Columbus, Ohio were used to examine vegetation dynamics in created wetlands (Fig. 3.1). The two experimental wetlands are each 1-ha in size and receive the majority of their hydrologic inputs via pumps from the Olentangy River 52 which boarders the 21-ha facility. Construction began in 1993, with river water input beginning March 1994. In spring 1994, an initial vegetation succession experiment was implemented in which wetland one was planted with 13 wetland species, while vegetation was allowed to naturally colonize wetland two. No tree species were planted along the edge of either wetland. 3.3.2 Structural Characteristics Structural vegetation characteristics of the two wetlands were examined annually from 2008-2010. Species richness, Ohio Floristic Quality Assessment Index (FQAI), Community Diversity Index (CDI), and type of vegetation were determined for each wetland. FQAI was determined using the equation: FQAI= ∑ ( CofC i )/ √(N ) where C of Ci is the coefficient of conservatism for each species as determined by Andreas et al. (2004). N is the number of native species. C of Ci values range from 0 to 10 based on degree of fidelity in relation to other species in Ohio (Andreas et al. 2004), with lower values being characteristic of species found in highly disturbed areas, while species with higher values tend to have narrow ecological niches (Lopez and Fennessy 2002; Ahn and Dee 2011). CDI was determined using the equation: CDI=−∑ (Ci ln C i ) where C is the relative area of each wetland community (Mitsch et al. 2005a,b). This equation is similar to that used for the Shannon-Wiener Diversity index commonly used in biological studies. CDI uses community area to estimate richness and evenness based 53 on the spatial patterns of the vegetation communities. Plant species can be separated into different categories based on habitat type. Reed (1998) categorizes wetland plants based on the probability that they are found in wetlands including statuses of obligate, facultative wet, facultative, facultative upland, or upland species. Obligate and facultative wet are considered to be wetland species in this study. All plant species found within the two wetlands were categorized using wetland indicator status. 3.3.3 Functional Characteristics Aboveground plant biomass was examined on a monthly basis over the course of the growing season (April – September) from 2008-2010. The sequential harvest method for aboveground net primary productivity (ANPP) was employed (Fahey and Knapp 2007). Live vegetation samples were harvested from within a 0.5m² sampling frame at ground level from 12 plots in each wetland. Plots were located in the dominant plant communities and were selected to be representative of the average within the community. Wet weight was determined in the lab shortly after harvesting. Harvested biomass was separated by species and dried at 105°C for 48 hours or until constant weight (Mitsch et al. 2006). Biomass measurements were weighted by community area using percent community area found using GPS data and aerial photographs multiplied by sample plots. The equation: ANPP=(b1-b0)+(b2-b1)+(b3-b2)+..... was used to estimate annual ANPP. b represents the biomass for a specific sampling event. Only positive accumulation from one month to the next was included (Fahey and 54 Knapp 2007). b0 is assumed to have a biomass of 0 g DW/m2 due to lack of production in winter months . Belowground biomass was sampled by taking 30 cm deep soil cores within each of the twenty-four areas sampled for aboveground biomass in the two wetlands. These samples were taken with a golf course hole cutter (10 cm diameter and approximate volume of 2356 cm³). Core samples were sectioned into 0-10 cm, 10-20 cm, and 20-30 cm depths and taken back to the lab. Samples were collected on a monthly basis from April through September for all three years of the study. Once in the lab, sectioned soil cores were passed through a sieve. All roots and rhizomes were oven dried at 105°C for 48 hours and then weighed to estimate belowground net primary productivity (g DM/ m2). Biomass measurements were weighted by community area using GPS data. Belowground net primary productivity (BNPP) on a monthly basis was estimated from belowground biomass samples using the equation: BNPPmonthly=(b2-b1)/(t2-t1) where b represents the biomass for a given sampling period and t represents the time of sampling. Annual BNPP was estimated using the equation: BNPPannual=bmax–bmin with bmax representing the last biomass sample and bmin representing the first biomass sample (Sala et al., 2000). Above and belowground net primary productivity for each sampling area was summed to determine total net primary productivity (TNPP). TNPP for all twelve area was then averaged to obtained total biomass in g DW/ m2 year. Functional group composition of the dominant plant communities was determined 55 for each wetland annually. Dominant species were categorized as either ruderal, interstitial, or matrix species using Boutin and Keddy's (1993) functional classification system of wetland macrophytes. Ruderals included obligate and facultative annuals that are found in highly disturbed areas and act as colonizing species. Interstitial species included reeds, clonal plants and tussocks that are seen during intermediate successional stages, while matrix species are clonal stress-tolerators and clonal dominants that tend to be found in natural wetlands and during later successional stages (Matthews and Endress 2010). The dominant macrophyte species were analyzed for nutrient composition in August 2010. Seventy-nine samples were collected from both experimental wetlands. Samples were dried at 65ºC for forty-eight hours. After drying, samples were cut into approximately 2.5 cm sections, put into a paper bag, and shaken to randomly distribute pieces of stems, leaves, and reproductive tissue. The samples were ground to a powder using a Cianflone Pica Blender-Mill model 2601. Analysis of the samples for N, P, K, Ca, Al, Fe, Mn, and Na was preformed by Service Testing and Research (STAR) Laboratory, Wooster, Ohio. Percent N was determined using the Dumas method of combustion analysis (AOAC International 2002) run on an Elementar America's VarioMax C-N combustion analyzer (OARDC 2012). Percent N was compared to 2004 and 2005 data collected in the same wetlands (Hernandez 2006). All other elements were ashed at 500°C and dissolved in 10% nitric acid. After dissolution, the samples were run on an Inductively Coupled Plasma spectrophotometer (Teledyne Leeman Labs Prodigy Dual View IPC) (OARDC 2012). 56 In addition to biomass within the wetlands, above and below ground biomass was measured in the surrounding edge. Woody and herbaceous edge vegetation were sampled in six transects along the inner wetland edge forest for each wetland. Each transect was 2-m wide and extended from the wetland edge to the upland forest edge. Length of transect varied from 8 to 27 m. Wetland edge boundary is defined as the point between macrophyte species and woody vegetation. Upland forest edge is defined as the boundary between wetland woody and herbaceous vegetation and upland woody and herbaceous vegetation. Both wetland edge and upland edge were determined via visual inspect of species present. Sampling occurred on a monthly basis from April - September 2008 and 2009. A 0.25m2 PVC sampling frame was used to sample herbaceous vegetation. All herbaceous material within the frame was harvested and dried in the same manner as vegetation within the wetlands. Belowground biomass was collected with a modified golf course hole cutter (diameter 5 cm). Samples were taken to a depth of 30 cm and have a volume of 1178 cm³. Cores were sectioned into 10 cm, 10-20 cm, and 2030cm depths. In the lab, roots and rhizomes were separated and dried using the methods explained above for macrophyte vegetation. ANPP and BNPP were estimated using the same equations used for macrophyte species. Total above ground biomass for woody vegetation of the edge was estimated from equations created by the USDA Forest Service (Jenkins et al. 2003) in 2008 and 2009. Diameter at breast height (dbh) was measure and species was determined for all trees within each transect. These measurements were put into the equations to determine biomass in kg DW/ m2. To determine aboveground net primary productivity of woody 57 vegetation, total aboveground biomass for 2008 was subtracted from total aboveground biomass for 2009. Twelve 0.25 m2 litter traps were placed within the transects to estimate litterfall from October 2008 through October 2009. Litter was collected from the traps on a bi-weekly basis. Litter was taken back to the lab and sorted into leaf, woody, and reproductive material and then dried for 48-hr at 105°C and used to determine net productivity from dry weight. 3.3.4 Statistical Analysis ANOVA and two-way ANOVA were used to test the structural and functional parameters. The statistical software program R was used to test assumptions and perform the statistical tests (determined assumptions were met using D’agostino skewness test, Anscomb-Glynn kurtosis test, Shapiro-Wilks normality test all at α= 0.1, normal quantile-quantile plots, and scatterplots) (The R Foundation for Statistical Computing 2009). Any non-normal data was either transformed or outliers were removed from the data set. Beaver herbivory of tree species within some of the edge transects was an issue throughout the study. Transects where large amounts of beaver herbivory occurred were discarded from tree primary productivity calculations and statistical analysis. Four transects were removed from both 2010 and 2011. Two-way ANOVA with independent variables of planted or unplanted and year of sampling was used to determine if there were any significant differences for structural characteristics and productivity measurements on both an annual and monthly basis over the three sampling years. ANOVA was used to examine vegetation nutrient content of the two wetlands. To deal with pseudoreplication issues due to the limited number of wetlands, 58 structural and annual functional characteristics were examined using one value per sampling year per wetland. Edge woody vegetation and litter trap data were examined on a transect and annual basis per wetland. Statistical analysis of nutrient composition was based on the total number of samples for nutrient analysis collected in 2010. Statistical tables can be found in Appendix F. 3.4 Results 3.4.1 Experimental Wetlands Within the two created wetlands, there was no statistical difference between year sampled for any of the structural parameters over the three years. There was also no difference for community diversity index (CDI) or number of macrophytes based on wetland (ANOVA p=0.512, F=0.624, df=1,2; ANOVA p=0.235, F=2.847, df=1,2 respectively). Ohio FQAI scores and species richness were both higher in the planted wetland (ANOVA p=0.002, F=540.8, df=1,2; ANOVA p=0.019, F=50, df=1,2) (Table 3.1). Dominant species differed between the two wetlands, with the planted wetland dominated by Scirpus fluviatilis, Sparganium eurycarpum, Typha spp. and the unplanted wetland dominated by Leersia oryzoides, Phragmites australis, Schoenoplectus tabernaemontani, and Typha spp (see Appendix D for community vegetation maps). All dominant species in the planted wetland were matrix species. In the unplanted wetland, three of the dominants species were matrix species, while the fourth was an interstitial species (Table 3.2). The unplanted wetland had more area occupied by invasive species (Phragmites australis 1.8%, 2.1%, and 3.4% for 2008, 2009, and 2010) than did the planted (0% all years). Nine of the thirteen originally planted species (Mitsch et al. 1998) 59 were present in the planted wetland. Weighted ANPP peaked in July for the planted wetland all three years and for the unplanted wetland in 2008 and 2009. In 2010, peak biomass occurred in August for the unplanted wetland (Fig. 3.2). ANPP was statistically different between the two wetlands (ANOVA p=0.006, F=158.62, df=1,2) and ranged from 673 to 712 g DW/m2 year in the planted wetland and 796 to 866 g DW/m2 year in the unplanted wetland. ANPP accumulation tended to be greatest in May, with accumulation rates ranging from 223 to 360 g DW/m2 month in the planted wetland and 285 to 555 g DW/m2 month in the unplanted wetland (Fig. 3.3). BNPP was about the same for the unplanted wetland (2132 to 2362 g DW/m2 year) and the planted wetland (1832 to 2170 g DW/m2 year) (ANOVA p=0.234, F=2.832, df=1,2). Monthly BNPP was highest in September (planted: 786 to 960g DW/m2 month; unplanted: 1108 to 1407 g DW/m2 month). Initial biomass readings in April suggest a stable rootstock of about 1000 to 1500 g DW/m2 within both wetlands (Fig. 3.4). Examining the depth profiles, the planted wetland had an average of 54% of root biomass within the 0-10 cm depth, 40% of root biomass within the 10-20cm depth, and 3% of root biomass within the 20-30 cm depth. The unplanted wetland had an average of 66% root biomass within the 0-10 cm depth, 25% root biomass within the 10-20 cm depth, and 5% root biomass within the 20-30 cm depth. Total net primary productivity (TNPP), ranged from 2505 to 2865 g DW/m2 year for the planted wetland and 2944 to 3041 g DW/m2 year for the unplanted wetland. There was no statistical difference between the two wetlands (ANOVA p=0.113, F=7.355, 60 df=1,2) or from one year to the next in each wetland (ANOVA p=0.207, F=3.385, df=1,2). The aboveground biomass within the planted and unplanted wetlands had nitrogen contents of 14.3±0.7 and 14.7±0.6 mg N/g respectively. Phosphorus content of the aboveground biomass was 2.1±0.22 mg/g in the planted wetland and 1.9±0.11 mg/g in unplanted wetland (Table 3.3). There was no statistically significant difference between the two wetlands for N or P (ANOVA p=0.445, F=0.59, df=1,77 and ANOVA p=0.953, F=0.004, df=1,77 respectively), nor was there a significant difference between 2010 and 2004/2005 N concentrations (ANOVA p=0.115, F=7.209, df=1,77). The planted wetland had higher concentrations of K, Ca, Al, and Fe (ANOVA p=0.003, F=9.652, df=1,77; ANOVA p=0.0499, F=3.969, df=1,77; ANOVA p=0.007, F=7.642 df=1,77; and ANOVA p=0.0351, F=4.603, df=1,77 respectively). Nutrient content differed by species for K, Ca, Al, and Fe (ANOVA p<0.001, F= 15.37, df=8,70; p<0.001, F=32.38, df=8,70; p=0.001, F=3.719, df=8,70; p=0.002, F=3.529, df=8,70, respectively). 3.4.2 Edge Vegetation Herbaceous vegetation peaked in August for both wetlands. Edge herbaceous aboveground net primary productivity (HANPP) averaged 111±10.1 g DW/m2 year for the planted wetland and 88±8.2 g DW/m2 year for the unplanted wetland. There was no statistical difference between the two wetlands or from one year to another (ANOVA p=0.368, F=2.351, df=1,1; ANOVA p=0.874, F=0.04, df=1,1 respectively) (Table 3.1). Edge belowground net primary productivity (EBNPP) was not significantly different between the two wetlands (ANOVA p=0.188, F=10.8, df=1,1), with the planted wetland 61 averaging 1602±598 g DW/m2 year and the unplanted wetland averaging 2143±1010 g DW/m2 year. EBNPP averages included all roots to a depth of 30 cm due to the difficulty in differentiating between herbaceous and woody fine roots. Tree aboveground net primary productivity was similar between the two wetlands (planted 1.25±0.23 kg DW/m2 year; unplanted 1.12±0.18 kg DW/m2 year) (ANOVA p=0.696, F=0.177, df=1,4). Litterfall around the edge of the wetlands was also similar; litterfall of the planted wetland was 528±42.8 g DW/m2 year, while litterfall of the unplanted wetland was 572±41.5 g DW/m2 year (ANOVA p=0.861, F=0.032, df=1,34). The majority of litterfall was from leaf litter, which made up 88% of litter around the planted wetland and 80% of litter around the unplanted wetland. Woody material made up the next largest portion, with 10% of litter around the planted wetland and 18% of litter around the unplanted wetland. Reproductive litter made up only 2% of the total litterfall for both wetlands (Fig 3.5). There were higher tree stem densities around the planted wetland (planted 2008: 1.10±0.16 stems/m2 and 2009: 0.99±0.14 stems/m2; unplanted 2008: 0.57±0.05 stems/m2 and 2009: 0.60±0.07 stems/m2)(ANOVA p<0.001, F=15.99, df=1,22). Dominant tree species in the edges of both wetlands included Acer saccharinum, Populus deltoides, and Salix nigra. 3.5 Discussion 3.5.1 Structure Of the two wetlands, the planted wetland had higher species richness, higher floristic quality, and a smaller amount of area occupied by invasive species. Initial creation and restoration techniques, such as planting, can have a significant impact on 62 vegetation structure at a site (Reinartz and Warne 1993; Gutrich et al. 2009). Gutrich et al. (2009) found that created wetlands in Ohio, where great care (i.e. planting and contouring of basins) was taken during initial restoration efforts, have been shown to have greater species richness and native species present than wetlands where less care was given to restoration. By planting not only a species rich assemblage of vegetation, but also including species with a variety of functional traits and niche requirements, it may be possible to create resilient communities that are resistant to future disturbances and invasion (Funk et al. 2008; Young et al. 2009). Early colonization by invasive species is of concern regarding long-term succession. Newly created ecosystems, i.e. highly disturbed systems, are more susceptible to invasion than less disturbed systems due to the high availability of resources, colonization opportunities, and open niches in these new ecosystems. Highly invasive species have the potential to persist in an ecosystem through later successional stages, which can interfere with vegetation succession and may lead to low diversity within communities (Zedler 2000; Catford et al., 2012). One way to discourage invasive species colonization is through planting (Middleton et al. 2010). The number of wetland species and Community Diversity Index did not differ between the two wetlands. The richness and evenness of vegetation communities was similar in the two wetlands, even though the dominant species differed. When trying to understand the function of a community, the exact species of a system and species richness may not be as important to ecosystem processes as the functional composition and traits of vegetation within the system (Diaz and Cabido 2001; McGill et al. 2006). 63 While two wetlands may have different species, as long as similar vegetation functional composition and traits are present, it should be possible for the two wetlands to have comparable function. 3.5.2 Function Of the functional characteristics examined, aboveground primary productivity was higher in the unplanted wetland, while some nutrient concentrations were higher in the planted wetland. All other functional parameters, including belowground net primary productivity and total net primary productivity, were similar between the planted and unplanted wetland. Functional group makeup of the dominant species was also similar between the two wetlands. Both productivity and nutrient concentration are related to the species present within the wetland. High productivity is not always considered to be a desirable characteristic because it may be an indication that invasive species are present at a site. In monocultures of Phragmites australis, ANPP can be as high as almost 2000 g DW/m2 year (Tanner 1996; Windham 2001), approximately double the productivity of the wetlands in this study. However, high primary productivity, when coupled with slow decomposition rates of organic matter, results in carbon being sequestered in the soil (Hossler and Bouchard 2010). Carbon sequestration is a desirable wetland function that aids in the reduction of greenhouse gases from the atmosphere, a function that should be given consideration when constructing a wetland (NRC 2001). Both wetlands had high total and belowground net primary productivity. While most soil carbon from vegetation is the result of plant tissue decomposition, exudates from belowground plant material is 64 also an important source of carbon to the soil (De Deyn et al. 2008). Similar belowground net primary productivity suggests that carbon exudates into the soil may be similar in the two wetlands, while similar total net primary productivity suggests that soil carbon from plant decomposition may also be similar in the two wetlands. Another goal of created wetlands is often to reduce the nutrient content, primarily N and P, of water passing through the wetlands. In the Midwest, N is of particular concern due to widespread fertilizer application on agricultural fields. This results in nutrient run-off from the fields, introducing a large amount of N into adjacent and downstream water bodies (Mitsch et al. 2001: Mitsch and Day 2006). In the experimental wetlands, there was no difference between the two wetlands for vegetation N or P concentration nor was there any difference generally between N and P retention by the wetlands (Mitsch et al. 2012), suggesting that planting does not have an effect on plant N or P uptake. Other elements are important in N and P cycles in wetlands and can effect their removal rates from water. Availability of Fe in wetlands is essential in N2 fixation, the process of converting atmospheric N2 to biologically available N, thus increasing N within the system. Increased Fe availability has a positive effect on N2 fixation (Reddy and DeLaune 2008). In contrast, Ca, Fe, and Al are capable of forming precipitates with available phosphates in both the water and soil. These precipitates are insoluble and thus biologically unavailable. The formation of precipitates is important in the sedimentation and storage of P within the soil (Mitsch and Gosselink 2007). Since different species have different nutrient uptake abilities (Tanner 1996; Jampeetong et al. 2012), if planting 65 is to occur, it may be beneficial to consider how nutrient uptake of the plant species may alter levels of available nutrients within the system in order to maximize removal rates of nutrients such as N and P. 3.5.3 Edge vegetation Planting seems to have no effect on the structure and function of vegetation in the edge area. From a successional standpoint, marsh habitat is not an endpoint system in Ohio, only a stepping stone to swamp habitat. As is, the two edge areas seem to be on a similar successional trajectory, which would suggest that when these wetlands transition to swamp habitat they may have similar structural and functional characteristics. However, future disturbances and the presence of ecosystem engineers (beavers and muskrats) have the potential to alter current trajectories (Wright and Jones 2004; Walker and del Moral 2008). Beaver herbivory is already occurring in the edge areas of the two wetlands. Studies have shown that when ecosystem engineers alter productivity of a system they also alter species richness (Wright and Jones 2004). The removal of trees from the edge area opens habitat for both herbaceous and woody species, i.e. the opportunity to increase species richness of the area while productivity has been decreased. The duration and degree of beaver herbivory of both edge areas will likely determine how the successional trajectories of the two wetlands will differ in the future. 3.5.4 Conclusions The decision to plant a wetland may come down to the of goals of the creation or restoration project. If vegetation structure is a priority, planting seems to be beneficial. However, if vegetation function is a priority, planting is not a necessity where propagules 66 are readily available. Even when propagules are introduced to an ecosystem via natural means, planting of a created wetland may still be a beneficial practice. Planting may help to improve the structural vegetation characteristics of a site by increasing species diversity and quality, which may help limit invasive species in the system. There is no way to control the species entering the system, so while some propagules species may be desirable, it is likely that invasive species are also entering the system. If space and nutrients are already being utilized by vegetation, as opposed to a bare mud flat, there is less chance that invasive species will be capable of becoming established in the system or at the very least taking over the system. The best approach may be to plant as many species as possible in the system and allow the wetland to “self-design”, instead of implementing rigid planting protocols with specific spatial composition (Mitsch and Wilson 1996). While this experiment provides a unique opportunity to observe the effects of planting on wetland vegetation development of two created wetlands where hydrologic, nutrient and location variables are controlled for, it is important to note that only two wetlands were studied. Both wetlands are riverine, surface flow wetlands with unidirectional flow, so extrapolating the results to other wetland types or similar wetlands in different landscapes should be done with caution. 3.6 References Ahn, C., & Dee, S., 2011. Early development of plant community in a created mitigation wetland as affected by introduced hydrologic design elements. Ecological 67 Engineering 37, 1324-1333. Andreas, B.K., Mack, J.J., & McCormac, J.S. ,2004. Floristic Quality Assessment Index (FQAI) for vascular plants and mosses for the State of Ohio. Ohio Environmental Protection Agency, Division of Surface Water, Wetland Ecology Group, Columbus, Ohio. 219 p. AOAC International, 2002. AOAC official method 990.03 Protein (crude) in animal feed combustion method. Official Methods of Analysis AOAC International 17th edn. (eds. W. Horwitz), Ch4 pp. 26-27. AOAC International, Gaithersburg, MD, USA. Balcombe, C.K., Anderson, J.T., Fortney, R.H., Rentch, J.S., Grafton, W.M., & Kordek, W.S., 2005. A comparison of plant communities in mitigation and reference wetlands in the Mid Appalachians. Wetlands 25,130-142. Bantilan-Smith, M., Bruland, G.L., MacKenzie, R.A., Henry, A.R., & Ryder, C.R., 2009. A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai'i. Wetlands 29, 1023-1035. Boutin, C., & Keddy, P.A., 1993. A functional classification of wetland plants. Journal of Vegetation Science 4, 591-600. Bruland, G.L., & Richardson, C.J., 2005. Spatial variability of soil properties in created, restored, and paired natural wetlands. Soil Science Society of America Journal 69, 273-284. Campbell, D.A., Cole, C.A., & Brooks, R.P., 2002. A comparison of created and natural wetlands in Pennsylvania, USA. Wetland Ecology and Management 10, 41-49. Catford, J.A., Daehler, C.C., Murphy, H.T., Sheppard, A.W., Hardesty, B.D., Westcott, 68 D.A., Rejmánek, M., Bellingham, P.J., Pergl, J., Horvitz, C.C., & Hulme, P.E., 2012. The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management. Perspectives in Plant Ecology, Evolution and Systematics, http://dx.doi.org/10.1016/j.ppees.2011.12.002 Choi, Y.D., 2004. Theories for ecological restoration in changing environment: Toward a 'futuristic' restoration. Ecological Research 19, 75-81. De Deyn, G.B., Cornelissen, J.H.C., & Bardgett, R.D., 2008. Plant functional traits and soil carbon sequestration in contrasting biomes. Ecology Letters 11, 516-531. Diaz, S., & Cabido, M., 2001 Vive la difference: plant functional diversity matters to ecosystem processes. Trends in Ecology and Evolution 16, 646-655. Fahey, T.J. & Knapp, A.K. (edts.) 2007. Principles and stanrds for measuring primary production. Oxford university press. Fennessey, S., & Roehrs, J., 1997. A functional assessment of mitigation wetlands in Ohio: Comparisons with natural systems. Ohio Environmental Protection Agency Division of Surface Waters, Columbus, Ohio. Funk, J.L., Cleland, E.E., Suding, K.N., & Zavaleta, E.S., 2008. Restoration through reassembly: plant traits and invasion resistance. Trends in Ecology & Evolution 23, 695–703. Gutrich, J.J., Taylor, K.J., & Fennessy, M.S., 2009. Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): The importance of initial effort for mitigation success. Ecological Engineering 35, 351-368. 69 Hernandez, M.E., 2006. The effect of hydrologic pulses on nitrogen biogeochemistry in created riparian wetlands in Midwestern USA (dissertation). The Ohio State University, Columbus, OH. Hossler, K., & Bouchard, V., 2010. Soil development and establishment of carbon-based properties in created freshwater marshes. Ecological Applications 20, 539-553. Jampeetong, A., Brix, H., & Kantawanichkul, S., 2012. Effects of inorganic nitrogen forms on growth, morphology, nitrogen uptake capacity and nutrient allocation of four tropical aquatic macrophytes (Salvinia cucullata, Ipomoea aquatica, Cyperus involucratus, and Vetiveria zizanioides). Aquatic Botany 97, 10-16. Jenkins J.C., Chojnacky, D.C., Heath, L.S., & Birdsey, R.A., 2003. National-scale biomass estimators for United States tree species. Forest Science 49, 12-35. Lopez, R.D., & Fennessy, M.S., 2002. Testing the floristic quality assessment index as an indicator of wetland condition, Ecological Applications 12, 487-497. Matthews, J.W., Spyreas, G. & Endress, A.G., 2009. Trajectories of vegetation-based indicators used to assess wetland restoration progress. Ecological Applications 19, 2093-2107. Matthews, J.W., & Endress, A.G., 2010. Rate of succession in restored wetlands and the role of site context, Applied Vegetation Science 13, 346-355. McGill, B.J., Enquist, B.J., Weiher, E., & Westoby ,M., 2006. Rebuilding community ecology from functional traits. Trends in Ecology and Evolution 21, 178-185. Middleton, E.L., Bever, J.D., & Schultz, P.A., 2010. The effects of restoration methods on the quality of the restoration and resistance to invasion by exotics. Restoration 70 Ecology 18, 181-187. Mitsch, W.J., & Wilson, R.F., 1996. Improving the success of wetland creation and restoration with know-how, time, and self-design. Ecological Applications 6, 7783. Mitsch, W.J., X. Wu, R.W. Nairn, P.E. Weihe, N. Wang, R. Deal, & Boucher, C.E., 1998. Creating and restoring wetlands: A whole-ecosystem experiment in self-design. BioScience 48, 1019-1030. Mitsch, W.J., Day Jr., J.W., Gilliam, J.W., Groffman, P.M., Hey, D.L., Randall, G.W., & Wang, N., 2001. Reducing nitrogen loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to counter a persistent large-scale ecological problem. BioScience 51, 373-388 Mitsch, W.J., Wang, N., Zhang, L., Deal, R., Wu, X., & Zuwerink, A., 2005a. Using ecological indicators in a whole-ecosystem wetland experiment. Handbook of Ecological Indicators for Assessment of Ecosystem Health. CRC Press, Boca Raton, FL., pp. 211-236. Mitsch, W.J., Zhang, L., Anderson, C.J., Altor, A., & Hernandez, M., 2005b. Creating riverine wetlands: Ecological succession, nutrient retention, and pulsing effects, Ecological Engineering 25, 510-527. Mitsch W.J, Anderson, C.J., Hernandez, M.E., & Zhang, L., 2006. Net primary productivity of macrophyte communities in the experimental marshes after twelve growing seasons. Wilma H. Schiermeier Olentangy River Wetland Research Park Annual Report 2005, 107-110. 71 Mitsch, W.J. & Day Jr., J.W., 2006. Restoration of wetlands in the Mississippi-OhioMissouri (MOM) River Basin: Experience and needed research. Ecological Engineering 26, 55-69. Mitsch, W.J. & Gosselink, J.G., 2007. Wetlands (4th edt). John Wiley & Sons, Inc. Hoboken, New Jersey. Mitsch, W.J, Zhang, L., Stefanik, K.C., Nahlik, A.M., Anderson, C.J., Bernal, B., & Song, K., 2012. Creating wetlands: A 15-year study of primary succession, water quality changes, and self-design. BioScience 62, 237-250.. National Research Council, 2001. Compensating for wetland losses under the Clean Water Act, Committee on Mitigating Wetland Losses, National Academies Press, Washington, DC. Ohio Agricultural Research and Development Center (OARDC), 2012. Methods and References. STAR Lab, http://www.oardc.ohio-state.edu/starlab/t08_pageview3/References.htm. The R Foundation for Statistical Computing, 2009. R version 2.10.1 (2009-12-14). Reddy, K.R. & DeLaune, R.D., 2008. Biogeochemistry of wetlands science and applications. CRC Press, Boca Raton, FL. Reed, PB., 1988 National list of plant species that occur in wetlands: Northeast (Region 1). U.S. Fish and Wildlife Service Biological Report 88(26.1). Reinartz, J.A. & Warne, E.L., 1993. Development of vegetation in small created wetlands in southeast Wisconsin. Wetlands 13, 153-164. Sala, O.E., Jackson, R.B., Mooney, H.A., & Howarth, R.W., 2000. Methods in 72 ecosystem science. Springer, New York. Spieles, D.J., Coneybeer, M., & Horn, J., 2006. Community Structure and Quality After 10 Years in Two Central Ohio Mitigation Bank Wetlands. Environmental Management 38, 837-852. Stefanik, K.C., & Mitsch, W.J., 2012. Structural and functional vegetation development in created and restored wetland mitigation banks of different ages. Ecological Engineering 39,104-112. Suding, K.N., & Cross, K.L., 2006. The dynamic nature of ecological systems: Multiple states and restoration trajectories. Foundations of Restoration Ecology (eds D.A. Falk, M.A. Palmer, & J.B. Zedler) pp. 190-209 Island Press, Washington, D.C. Tanner, C.C., 1996. Plants for constructed wetland treatment systems – A comparison of the growth and nutrient uptake of eight emergent species. Ecological Engineering 7, 59-83. van der Valk, A.G., Toth, L.A., Gibney, E.B., Mason, D.H., & Wetzel, P.R., 2009. Potential propagule sources for reestablishing vegetation on the floodplain of the Kissimmee river, Florida, USA. Wetlands 29, 976-987. Walker, L.R. & del Moral, R., 2008. Transition dynamics in succession: Implications for rates, trajectories, and restoration. New Models for Ecosystem Dynamics and Restoration (eds K. Suding & R.J. Hobbs), pp. 33-49 , Island Press, Washington, D.C. White, P.S. & Jentsch, A., 2001. The search for generality in studies of disturbance and ecosystem dynamics. Progress in Botany 62, 399-450 73 Windham, L., 2001. Comparison of biomass production and decomposition between Phragmites australis (common reed) and Spartina patens (salt hay grass) in brackish tidal marshes of New Jersey, USA. Wetlands 21, 179-188. Wright, J.P. & Jones, C.G., 2004. Predicting effects of ecosystem engineers on patchscale species richness from primary productivity. Ecology 85, 2071-2081. Young, S.L., Barney, J.N., Kyser, G.B., Jones, T.S. & DiTomaso, J.M., 2009. Functionally similar species confer greater resistance to invasion: Implications for grassland restoration. Restoration Ecology 17, 884-892. Zedler, J.B, 2000. Progress in wetland restoration and ecology. Trends in Ecology and Evolution 15, 402-407. 74 Table 3.1 Average ± standard error of structural and functional characteristics of the two experimental wetlands and edge area. - indicates sampling did not occur for that year. Wetland 1 (W1) was planted in 1994 and Wetland 2 (W2) was left unplanted. ANOVA was used to examine significant differences. Pseudoreplication was an issue with this study. Each structural and annual functional characteristic is represented by one number per wetland per year. Significant p-values are in bold. 2008 2009 2010 P-values W1 W2 W1 W2 W1 W2 Wetland Year 97 92 98 92 99 95 0.019 0.102 FQAI 23.8 19.9 23.2 20 23.2 19.9 0.002 0.242 CDI 1.71 1.26 1.16 1.45 1.45 1.03 0.512 0.50 55 52 52 46 51 49 0.235 0.319 Aboveground NPP (g DW/m2 year) 712 ±102 796 ±99 703 ±98 812 ±20 673 ±87 866 ±108 0.006 0.34 Belowground NPP (g DW/m2 year) 2170 ±303 2362 ±336 2163 ±312 2132 ±408 1832 ±307 2175 ±334 0.234 0.165 Total NPP (g DW/m2 year) 2882 ±334 3158 ±357 2865 ±323 2944 ±391 2505 ±462 3041 ±384 0.113 0.207 Edge herbaceous aboveground NPP (g DW/m2 year) 117 ±5 105 ±6 79 ±14 97 ±15 - - 0.368 0.875 Edge belowground NPP (g DW/m2 year) 2200 ±434 1004 ±572 3153 ±181 1133 ±396 - - 0.188 0.205 Litterfall (g DW/m² year) - - 528 ±42 572 ±41 - - 0.860 - Tree aboveground NPP (g DW/m2 year) - - 1250 ±230 1120 ±180 - - 0.696 - Species richness # macrophytes 75 Table 3.2 Functional classification and percent cover of the dominant plant communities in the planted and unplanted wetlands. * denotes invasive species. % Cover 2008 % Cover 2009 % Cover 2010 Functional Classification Planted Unplanted Planted Unplanted Planted Unplanted Interstitial 0.5% 29% 0% 6.7% 0% 0% Phragmites australlis * Matrix 0% 1.8% 0% 2.1% 0% 3.4% Schenoplectus tabernaemontani Matrix 2% 2.9% 0% 13.2% 3% 9% Matrix 3% 0% 4% 0% 3.5% 0% Sparganium eurycarpum Matrix 19% 0% 18% 0% 16.4% 0% Typha spp. Matrix 27% 33% 45% 34% 40% 55% Species Leersia orizoides Scirpus fluviatilis 76 Table 3.3 Average nutrient content of aboveground biomass from August 2010. Nutrient content is shown for each dominant species, as well as each wetland. (N) indicates number of samples. Average mg/g DW ± SE N P K Ca Al 15.4 2 20.1 6 0.3 ±1.1 ±0.27 ±2.0 ±0.45 ±0.10 13.5 1.4 15.5 11.8 0.2 Typha spp. (19) ±1.0 ±0.11 ±1.2 ±0.87 ±0.05 Leersia oryzoides 13.5 1.8 9.7 3.5 0.4 (22) ±0.6 ±0.09 ±0.6 ±0.15 ±0.08 15.2 3 15.9 5.3 0.3 Eleocharis obtusa (2) ±0.1 ±0.21 ±1.2 ±0.40 ±0.03 Sparganium 15.2 2.1 20.8 13.8 0.6 eurycarpum* (9) ±1.3 ±0.34 ±1.6 ±0.69 ±0.37 Sciprus fluviatilis* 12.8 1.7 18.7 2.5 0.4 (6) ±2.8 ±0.36 ±2.1 ±0.36 ±0.08 Sagittaria latifolia* 19.6 4.9 39.8 6.9 0.7 (5) ±0.7 ±0.97 ±4.5 ±1.20 ±0.25 Nelumbo lutea* (1) 22.9 3.1 27.8 12.4 0.1 Phragmites 13.4 1.1 7 3.2 0.01 australis† (3) ±1.9 ±0.16 ±0.3 ±0.29 ±<0.001 14.3 2.1 19.5 8.3 0.5 Planted (42) ±0.7 ±0.22 ±1.6 ±0.73 ±0.10 14.7 1.9 13.6 6.2 0.2 Unplanted (37) ±0.6 ±0.11 ±1.1 ±0.72 ±0.03 *Species present only in planted wetland †Species present only in unplanted wetland Species (N) Schoenoplectus tabernaemontani (11) 77 Fe 0.37 ±0.08 0.23 ±0.04 0.39 ±0.07 0.56 ±0.05 0.62 ±0.32 0.38 ±0.07 0.65 ±0.22 0.14 0.05 ±0.004 0.48 ±0.08 0.26 ±0.03 Mn 0.21 ± 0.021 0.17 ±0.008 0.1 ±0.009 0.33 ±0.005 0.21 ±0.018 0.16 ±0.036 0.1 ±0.032 0.24 0.16 ±0.019 0.16 ±0.010 0.16 ±0.013 Na 0.9 ±0.13 3.5 ±0.40 0.1 ±0.01 0.6 ±0.29 1 ±0.13 0.8 ±0.19 0.9 ±0.36 1.5 0.1 ±0.01 1.2 ±0.15 1.4 ±0.34 Figure 3.1 This study was conducted in the two 1-ha experimental wetlands at the Olentangy River Wetland Research Park. The western basin was planted with 2500 individual propagules representing 13 wetland species, while the eastern basin was left to colonize naturally. 78 Figure 3.2 Monthly weighted aboveground biomass of the two wetlands with standard error. Overall, the unplanted wetland was more productive than the planted wetland. Peak biomass occurred in July of all three years for the planted wetland, while peak biomass occurred in July 2008/2009 and August 2010 for the unplanted wetland. Peak biomass is a rough approximation of annual aboveground net primary productivity. 79 Figure 3.3 Accumulation of monthly weighted aboveground net primary productivity of the wetlands from 2008 to 2010. Accumulation was highest from April to May for all six sample events. After July, for all sampling events except W2-2010, productivity accumulation switched to senescence. W# indicates the wetland and -## indicates the year sampled. Wetland 1 (W1) was planted and Wetland 2 (W2) was unplanted. 80 Figure 3.4 Monthly belowground biomass of the two wetlands with standard error bars. Belowground net primary productivity (BNPP) was estimated by subtracting April measurements from September measurements. There was a continuous overwinter rootstock ranging from 1000 to 1500 g DW/m2 year as evident by the April measurements. BNPP ranged from 1800 to 2400 g DW/m2 year. 81 Figure 3.5 Tree aboveground net primary productivity (ANPP) and standard error of the interior edge of each wetland. Equations from Jenkins et al. (2003) were used to estimate tree ANPP. Litter traps were used to determine the amount of foliage and reproductive material contributing to tree ANPP. There was no difference in tree ANPP or litterfall between the two wetlands. 82 Chapter 4: Metabolism and methane flux of dominant macrophyte communities in created riverine wetlands using open system flow through chambers 4.1 Abstract Estimating net primary productivity of macrophytes is a common practice in wetland research, but much less is done regarding estimating gross primary productivity (GPP) and respiration (R) of wetland macrophyte communities. The purpose of this project was to estimate both the metabolism (GPP and R) and greenhouse gas emissions (methane) of selected wetland macrophyte communities using an open system flowthrough chamber technique to determine the gaseous carbon budget of different plant communities. Large (0.5 m2 sample area, 1.6 and 2.6 m tall) flow through chambers were placed over dominant macrophytes species (2010: Typha spp., Scirpus fluviatilis, Sparganium eurycarpum, and Phragmites australis; 2011: Typha spp., Scirpus fluviatilis, Phragmites australis, and open water) in the two experimental wetlands at the Olentangy River Wetland Research Park in central Ohio, USA. Gas samples were collected over a 48-hr period monthly from April through September. Samples were collected using a vial and syringe method from the chambers every odd hour between sunrise and sunset to estimate photosynthesis, along with two nightly samples to estimate respiration. Overall metabolism measurements were similar in the two years: 2010, GPP = 13.9 ± 1.2 g CO2C/m2 day; R 83 = 12.1 ± 1.0 g CO2-C/m2 day; 2011, GPP = 13.9 ± 1.1 g CO2-C/m2 day; R = 12.9 ± 0.6 g CO2-C/m2 day. GPP peaked in June 2010 and in July 2011 and overall was approximately 3.7% of solar radiation. GPP differed by both month sampled and plant community (p<0.001 and p=0.002, respectively). Phragmites australis and Typha spp. had higher average GPP than did open water and Phragmites australis had higher GPP than Scirpus fluviatilis. Median methane emissions from the sample plots were 12.8 mg CH4-C/m2 day and differed by month (p<0.001) and soil temperature (p=0.049). There was a net retention of carbon in the two experimental wetlands ranging from 160 to 195 g C/m2 year in 2010 and from 164 to 171 g C/m2 year in 2011. 4.2 Introduction The gaseous carbon budget of a wetland depends on the amount of carbon taken up as carbon dioxide during photosynthesis and the amount of carbon lost as either carbon dioxide from plant and soil respiration or as methane emitted by methanogenesis (Whiting and Chanton 2001; Cornell et al 2007; Yvon-Durocher et al. 2007). The overall limit of heterotrophic activity within an ecosystem is established mainly by the amount of carbon acquired by a system through gross primary productivity (Cornell et al. 2007). Gross primary productivity is dependent on the plant species present, available solar radiation, available water and nutrients, and temperature (Running et al. 2000). Many species have an optimum temperature for photosynthesis that tends to be near the mean daytime temperature of an ecosystem. If temperature is drastically different from the optimum, either low or high, gross primary productivity measurements will be low. 84 Limitation in available solar radiation will also lead to low relative gross primary productivity. Respiration, unlike gross primary productivity, tends to increase exponentially with temperature, so under high temperature conditions it is possible for respiration to exceed gross primary productivity (Aber and Milillo 2001; Yvon-Durocher et al 2011). Methanogensis occurs under reduced, anaerobic condition by methanogen bacteria. These conditions are likely to form under prolonged periods of hydrologic inundation within wetland ecosystems (Mitsch and Gosselink 2007; Altor and Mitsch 2008). Methanogens utilize organic matter within a system to produce methane (Mitsch and Gosselink 2007). Methane emissions can be reduced by methanotrophic bacteria that oxidize methane within the soil and water, while producing carbon dioxide (Segers 1998; Mitsch and Gosselink 2007; Altor and Mitsch 2008). Methanogenesis is likely linked to soil temperature, either directly or in combination with other environmental factors (Schutz et al. 1990; Gedney et al. 2004). A positive correlation has been found between soil temperature and methane emissions in temperate freshwater wetlands (Altor and Mitsch 2008; Nahlik and Mitsch 2010; Sha et al. 2011). Soil carbon content and hydrologic gradient (slope of the water table) have also been found to have a positive relationship with methane emissions (Altor and Mitsch 2008; Koh et al. 2009; Sha et al. 2011). Gross primary productivity may influence the amount of methane production within an ecosystem (Joabsson et al. 1999), with up to 15% of carbon fixed possibly being released as methane (Brix et al. 2001). Root carbon exudates and litter production 85 act as a source of organic matter for methanogen bacteria (Chanton et al 1995; Whalen 2005; Joabsson et al. 1999). High primary productivity leads to an increase in root exudates and litter production of a system, thereby increasing the amount of raw material for methanogens to utilize. However, oxygen released from roots can decrease methane emissions by facilitating methanotrophy (Whalen 2005). Due to the anaerobic conditions found in wetlands, methane emissions compared to other types of ecosystems tend to be somewhat high, with wetlands and areas with very high water tables being methane sources while most dry ecosystems are methane sinks (Smith et al 2000; Whiting and Chanton 2001). Wetland methane emissions account for approximately 20 – 25% of global methane emissions, with the remainder coming from anthropogenic sources (Mitsch and Gosselink 2007; Nahlik and Mitsch 2011). The balance of carbon released and carbon taken up by the system will determine if a wetland is acting as a sink or a source of carbon (Whiting and Chanton 2001). Understanding carbon flux in terms of both carbon dioxide and methane is of particular importance due to the role these gases play in global climate change. Of these two gases, methane is considered to be of great concern since it has a global warming potential of 25 compared to carbon dioxide's global warming potential of 1 (IPCC 2007). Thus, small changes in levels of methane will have a greater impact on global climate change than small changes in level of carbon dioxide. There has been debate as to the role of wetlands as carbon sinks or sources. It has been suggested that in freshwater wetlands in North America, wetland carbon sequestration is offset by the amount of methane produced (Bridgham et al 2006). Other studies have suggested that over the 86 long term (100 to 500 year time frame), wetlands act as carbon sinks and thus are capable of alleviating the effects of global climate change regardless of whether they emit methane (Brix et al 2001; Whiting and Chanton 2001; Mitsch et al. in final review). Newly created and restored wetlands are likely to act as carbon sinks, due to the rate of organic soil carbon increase, compared to natural wetlands, outweighing lower rates of methane production (Badiou et al. 2011). Measurements of gross primary productivity, respiration, and methane emissions can be done on many different scales, including individual leaf analysis, chambers, large scale enclosures covering a portion of an ecosystem, and eddy flux towers (Ruimy et al. 1995). With chamber methods, these can either be open or closed systems, both of which have their pros and cons. Open system chambers can be used for extended periods of time, but require controlled air movement through the chamber to maintain chamber temperature within range of ambient (Drake and Read 1981; Streever et al 1998). Closed system chamber are simple, non-mechanical structures, but can only remain in place for a short period of time due to increased temperature within the chamber which can alter ecosystem processes (Streever et al 1998). This paper describes gross primary productivity and respiration of the dominant macrophyte communities in 18-year-old created marshes in central Ohio, as well as methane emissions from those communities, using open system flow through chambers over the course of the growing season. It is hypothesized that there will be a significant difference between the planted and unplanted dominant species in the two wetlands, with the unplanted naturally occurring species having higher gross primary productivity and 87 respiration rates than the planted species in the wetlands due to the higher net primary productivity of the unplanted dominant species compared to the planted dominant species. It is also hypothesized that there will be an overall net retention of carbon in the wetland communities, i.e. the amount of carbon taken up through gross primary productivity will be larger than the amount of carbon lost through respiration and methane emissions. 4.3 Methods 4.3.1 Study Site The two experimental wetlands at the Olentangy River Wetland Research Park, Ohio State University, Columbus, Ohio were used to examine ecosystem function of created riverine wetlands. The two experimental wetlands are each one ha in size and receive the majority of their water inputs via pumps from the Olentangy River which runs along the north and east boarder of the 52-acre facility. Construction began in 1993 and water began flowing into the wetlands in March 1994. In the spring of 1994, an initial vegetation succession experiment was implemented in which one wetland (Wetland 1) was planted with 13 wetland species, while vegetation was allowed to colonize Wetland 2 naturally (Mitsch et al. 1998, 2012). The dominant plant communities in these two wetlands include Typha spp. (Typha latifolia, Typha angustifolia, and Typha X glauca), Sparganium eurycarpum, Scirpus fluviatilis, and Phragmites australis. Sparganium eurycarpum and Scirpus fluviatilis were both planted in Wetland 1 during initial construction. Typha spp. and Phragmites australis colonized the wetlands naturally. 88 Phragmites australis is only present in the unplanted Wetland 2. All four species are perennials. 4.3.2 Chamber Design Metabolism of the herbaceous vegetation was measured for the major plant communities for each of the experimental wetlands at the ORW on a monthly basis from April – September of 2010 and 2011. Chambers were set up in four dominant plant communities in 2010 and set up in three dominant plant communities and one open water site in 2011. Each community was monitored with two chambers per month, which were run for approximately 48 hours at a time. Sampling occurred every odd hour between sunrise and sunset to determine GPP, while sampling to measure R occurred once a night (after sunset) in 2010 and twice during the night (after sunset and before sunrise) in 2011. Each chamber consisted of a plastic bag fitted over a PVC pipe frame that sat on a wood and plexi-glass base (Fig. 4.1). Chamber bases covered a 0.5 m2 area of soil and were pushed 10 cm into the soil surface. The plastic bag and PVC pipe frame were sealed to the chamber base using all-weather tape. Two different frame heights were used, 1.4 m and 2.4 m, depending on the height of the vegetation to be measured. Each chamber had an inflow pipe near the base of the chamber and an outflow pipe coming out of the top of the chamber. The inflow pipe was made of pvc pipe and semi-rigid aluminum pipe. The 1.83 m pvc pipe had a fan with a range of 40 to 250 cfm air flow at one end, a pitot tube near the middle, and a semi-rigid aluminum pipe at the other end that connected to the chamber. A manometer was connected to the pitot tube to measure air flow through the chamber. Sampling ports were located on the inflow pvc pipe and 89 the outflow pipe (Fig. 4.1). The fan was used to force air through the chamber (Oechel et al. 2000). A 0.7-m outflow pipe was positioned at the top of the chamber. In 2010, the outflow pipe was positioned horizontally at the top of the chamber, but in 2011 was moved to a vertical position to help reduce heat build up in the chamber. Air flow was maintained at a rate to keep the air in the chamber within approximately 2 ºC of the ambient temperature since temperature affects vegetation metabolism (Drake and Read 1981; Rasse et al. 2002) yet not so rapid as to eliminate any change in gas concentrations from inflow to outflow. 4.3.3 Sampling Gas samples were collect from the inflow and outflow sampling ports using a vial and syringe method. Thirty ml of air was taken at each sampling event from both the inflow and outflow pipes and stored in 10 ml glass vials. The vials were stored in a dark, room temperature cabinet until they could be analyzed. Previous studies have seen CO2 concentrations in the range of 200 to 500 ppm or µl/l (Drake and Read 1981; Rasse et al. 2002). A Shimadzo GC-2014 gas chromatograph, set up to run greenhouse gases (CO2, CH4, and N2O) was used to analyze samples. Additionally, temperature (chamber, ambient, soil, and water), photosynthetically active radiation (PAR) (μmol/m2 s), and total solar radiation (W/m2) were measured at time of sampling. PAR was measured with a LICOR LI-190 quantum sensor and solar radiation was measured with a LI-COR LI-200 pyranometer. Both sensors were connected to a hand held LI-COR LI-250A Light meter with a digital display. Total solar radiation measurements from the hand held reader were compared to a permanently installed pyranometer at the weather station located between 90 the two wetlands. Change in carbon for each sampling period was determined by subtracting the inflow CO2 concentrations from the outflow CO2 concentrations. The ideal gas equation was used to convert from ppm CO2 to mg CO2-C/m3. These values were then multiplied by the rate of air flow through the chamber and then divided by the land surface area (0.5 m2) within the chamber to find the rate of CO2-C assimilated or respired (see Appendix E for equations). Rates were then weighted by time and adjusted for respiration. These rates were then summed over the course of a day to determine daily GPP for each chamber (Aber and Melillo 2001). Respiration measurements were determined by averaging night readings. These numbers were used to determine the amount of CO2 assimilation/respiration for each major plant community. Methane emission rates were found using the same method for determining GPP and respiration. In the 2011 growing season, the increase in water vapor from inflow to outflow was estimated to be <1 to 8% based on evapotranspiration estimates. Since there was minimal difference between inflow and outflow, humidity was not taken into account for the calculations of GPP, respiration, and methane emissions. Methane and respiration values were subtracted from GPP measurements to determine net ecosystem exchange of gaseous carbon (NEEC) and to determine if there is a net gain or loss in carbon within the sample plots. 4.3.4 Statistical Analysis The statistical software program R was used to test assumptions and perform the statistical tests (determined assumptions were met using D’agostino skewness test, 91 Anscomb-Glynn kurtosis test, Shapiro-Wilks normality test all at α= 0.1, normal quantilequantile plots, and scatterplots) (The R Foundation for Statistical Computing 2009). ANOVA was used to examine GPP and respiration measurements by year, month, species, and other environmental variables. Tukey multiple comparison of means test was used to examine differences between months and between species. Linear regression was used to determine if the relationship between the environmental variables and the dependent variables was positive or negative. Methane data was not normal and could not be normalized using standard transformations (data exhibited a positive skew). Since the data could not be normalized, the non-parametric Kruskal-Wallis test was used. A multiple comparison test was then used to examine differences between months. To alleviate issues relating to pseudoreplication, one point for GPP, R, and methane emissions was calculated per chamber per month. Statistical tables can be found in Appendix F. 4.4 Results Solar radiation averaged 3462 ± 140 kcal/m2 day in 2010 (at the weather station) and 4172 ± 170 kcal/m2 day in 2011 (at the study plots) over the course of the growing season. Average ambient temperature around the chambers was 23.1 ± 0.32 ºC and 23.9 ± 0.25 ºC for 2010 and 2011, respectively. In 2011, average water temperature and soil temperature were 22.0 ± 0.20 ºC and 20.8 ± 0.14 ºC. Water depth was approximately 38.10 ± 0.64 cm in the wetlands (Table 4.1). GPP and respiration over the course of the growing was not different between the two years (ANOVA p=0.997, F=0, df=1,38 and p=0.496 F=0.472, df=1,38) (Table 4.2). 92 Average GPP for 2010 was 13.93 ± 1.17g CO2-C/m2 day, while respiration was 12.08 ± 1.02 g CO2-C/m2 day. Average GPP for 2011 was 13.95 ± 1.08 g CO2-C/m2 day, while respiration was 12.86 ± 0.62 g CO2-C/m2 day. GPP was approximately 4.1% of solar radiation for Phragmites australis, 3.8% for Typha spp., 3.4% for Sparganium eurycarpum, 2.9% for Scirpus fluviatilis, and 1.9% for open water. GPP differed by both month and species (ANOVA p<0.001, F=6.364, df=5,34 and ANOVA p=0.003,F=4.965, df=1,35 respectively), while respiration differed by month (p=0.026) (Fig. 4.3). GPP peaked in June of 2010 and July of 2011. Comparing GPP to the environmental variables, there was a significant difference in GPP based on solar radiation (Linear regression p<0.001, F=15.71, df=1,38), ambient temperature (Linear regression p=0.002, F=11.69, df=1,32), and soil temperature (Linear regression p=0.001, F=13.02, df=1,32). There was a positive relationship between GPP and the three significant environmental variables. The only environmental variable that had a significant effect on respiration was ambient temperature (Linear regression p=0.038, F=4.71, df=1,32). Respiration increased with increasing ambient temperature. GPP was significantly higher for Phragmites australis (17.31 ± 1.43 g CO2-C/m2 day) and Typha spp. (16.08 ± 1.27 g CO2-C/m2 day) than for open water (9.85 ± 1.68 g CO2-C/m2 day) (Tukey Multiple Comparison of Means p=0.012, difference=7.40, lower=1.26, upper=13.53; and p=0.050 difference=6.23, lower=-0.015, and upper=12.47, respectively). Phragmites australis GPP was also significantly higher than Scirpus fluviatilis GPP (11.39 ± 0.98 g CO2-C/m2 day) (Tukey Multiple Comparison of Means p=0.029, difference=-5.86, lower=-11.29, and upper=-0.42). There was no difference 93 between Sparganium eurycarpum (11.37 ± 2.00 g CO2-C/m2 day) and any of the other species. Carbon use efficiency, the ratio of net primary productivity to gross primary productivity, is particularly high for Phragmites australis at 0.75. Carbon use efficiency for the remaining species was 0.47 for Typha spp., 0.37 for Sparganium eurycarpum, and 0.34 for Scirpus fluviatilis. Average carbon use efficiency of the four species was 0.56. Comparing GPP by month, June was statistical different from April (Tukey Multiple Comparison of Means p=0.0075, difference=9.35, lower=1.87, and upper=16.83) and September (Tukey Multiple Comparison of Means p=0.036, difference=-6.99, lower=-13.68, and upper=-0.30), while July was statistical different from April (Tukey Multiple Comparison of Means p=0.002, difference=10.12, lower=3.03, and upper=17.22), May (Tukey Multiple Comparison of Means p=0.043, difference=-5.91, lower=-11.70, and upper=-0.11), and September (Tukey Multiple Comparison of Means p=0.008, difference=-7.76, lower=-14.02, and upper=-1.51). As for respiration, May was statistically different than July (Tukey Multiple Comparison of Means p=0.05, difference=4.54, lower=-0.12, and upper=9.20). Median methane measurements for 2010 and 2011 were 10.76 mg CH4-C/m2 hr (min = -4.22 and max = 49.94mg CH4-C/m2 hr) and 14.96 mg CH4-C/m2 hr (min = -4.12 and max = 70.93 mg CH4-C/m2 hr). Methane measurements differed by month sampled (Kruskal-Wallis p<0.001, chi2=21.349, df=5), but did not differ by species or year sampled (p=0.3189 and Kruskal-Wallis p=0.123, chi2=2.3775, df=1) (Fig. 4.4). June was statistically different from April (Multiple Comparison Test after Kruskal-Wallis = True; Wilcoxon rank sum test with continuity correction p<0.001, w=5, 95% CI -28.88 to 94 -10.53) and September (Multiple Comparison Test after Kruskal-Wallis = True; Wilcoxon rank sum test with continuity correction p=0.004, w=213, 95% CI 6.11 to 21.98), while July was statistically different from April (Multiple Comparison Test after Kruskal-Wallis = True; Wilcoxon rank sum test with continuity correction p=0.001, w=16, 95% CI -36.16 to -6.60). Water depth and soil temperature produced significant differences in methane emissions (Kruskal-Wallis p=0.022, chi2=44.87, df=28 and Kruskal-Wallace p=0.049, F=48.732, df=34). Taking into account carbon losses from both respiration and methane emissions at the four vegetation communities and open water site, carbon uptake from GPP averaged 13.9 g C/m2 day over the two growing seasons, while carbon release from respiration was 12.5 g C/m2 day and from methane emissions was 0.3 g C/m2 day. NEEC was 1.1 g C/m2 day or approximately 200 g C/m2 over the growing season from April through September. Examining each community, average NEEc was 3.5 g C/m2 day for Typha spp., 3.9 g C/m2 day for Phragmites australis, 1.01 g C/m2 day for Sparganium eurycarpum, -0.22 g C/m2 day for Scirpus fluviatilis, and -2.5 g C/m2 day for open water. Extrapolating to the two experimental wetlands by weighting GPP, respiration, and methane measurements by community area (see Appendix D for vegetation community maps for 2010 and 2011), NEEc for the planted wetland was 160 g C/m2 year in 2010 and 164 g C/m2 year in 2011. NEEc for the unplanted wetland was 195 g C/m2 year in 2010 and 171 g C/m2 year in 2011. 95 4.5 Discussion 4.5.1 Gross Primary Production & Respiration As hypothesized, the two unplanted species, Phragmites australis and Typha spp., had higher gross primary productivity rates than one of the planted species, Scirpus fluviatilis. However, there was no difference between the two unplanted species and the other dominant planted species, Sparganium eurycarpum. These differences and lack there of are likely due to the physical and physiological traits of the species (i.e. height, area, and biomass of the vegetation). In 2010, total (above and belowground) net primary productivity of the four species sampled were 4300 g DW/m2 year and 3000 g DW/m2 year for the naturally colonizing vegetation P. australis and Typha spp. respectively, and 1600 g DW S. eurycarpum/m2 year, and 1000 g DW S. fluviatilis/m2 year for the planted vegetation S. eurycarpum and S. fluviatilis, respectively. Carbon use efficiency was somewhat higher in the unplanted species (Phragmites australis and Typha spp.) than the planted species. Average carbon use efficiency of the four species was 0.56, which is near carbon use efficiencies of 0.60-0.65 found in Typha marshes (Bonneville et al. 2008; Rocha and Goulden 2009). The high carbon use efficiency of Phramites australis likely plays a role in the ability of this invasive to out-compete native species. Invasives have been found to have higher resource-use efficiency rates (carbon assimilation per unit of resource) than native species in some ecosystems (Funk and Vitousek 2007). Cornell et al. (2007), who used static chambers to examine GPP and respiration over a chronosequence in created salt marshes compared to natural marshes, found macrophyte GPP and respiration rates similar to what was found in this study. GPP at 96 Cornell et al.'s sites ranged from approximately 10-24 umol CO2/s m2 (5-13 g C/m2 day assuming 12-hr day)and respiration rates of 5-17 umol CO2/s m2 (5-18 g C/m2 day). GPP in this study averaged 13.9 g C/m2 day and respiration of 12.5 g C/m2 day. A study of a Typha marsh in California from 1999-2007 using an eddy covariance tower found average GPP measurements of 1428 g C/m2 year where macrophyte average total net primary productivity (NPP) was 867 g C/m2 year (Rocha and Goulden 2009). The plots in this study had average GPP of approximately 2340 g C/m2 year and average NPP of 1045 g C/ m2 year, higher that what was found in the study by Rocha and Goulden (2009). Another study of temperate Typha marshes examining net ecosystem exchange found average monthly uptake values ranging from 0.1 to 5.1 g C/m2 day from June through September (Bonneville et al. 2008), with the average numbers for this study from all plots and most of the macrophyte communities falling within this range. The productivity and respiration measured over open water in this study (9.85 g C/m2 day GPP and 12 g C/m2 day R) were approximately ten times those measured and estimated by Tuttle et al (2007) (GPP averaged 0.54 g C/m2 day 2004, 1.08 g C/m2 day 2005; R averaged 0.54 g C/m2 day 2004 and 1.11 g C/m2 day 2005) by a dissolved oxygen diurnal method in the same wetlands six years previously. However, Tuttle at al. (2007) measurements were from April through June of each year, so peak production was not included in these averages. Another issue is that samples from the first year of the Tuttle et a. study occurred after pulsing hydrologic conditions (as opposed to stead flow conditions; can result in large water inflow rates due to storm events), which can decrease the productivity of the system through washout of algae and plankton (Altor and Mitsch 97 2008). Some of the discrepancy between studies may also be due to the method of measurement. With open system chambers, the temperature should be kept within ±2°C to minimize changes in the rates of photosynthesis and respiration within the chamber. The flow of air through the chamber can also alter rates of photosynthesis and respiration due to pressure gradients and if the air is moving through the chamber too quickly it may be difficult to detect differences between inflow and outflow readings (Drake and Read 1981; Streever et al. 1998; Dash and Dash 2009). When using oxygen sensors in the water column to measure productivity, the diffusion of oxygen out of the water column can cause an underestimate of gross primary productivity (Dash and Dash 2009). A lab study of different methods of measuring GPP and R from microalgae in sediments found that this method grossly underestimated GPP, primarily under higher light intensity conditions where oxygen would bubble out of the sediment and water column (Revsbech et al. 1981). Additional problems with bubbling can occur when sediments are disturbed. 4.5.2 Carbon Balance and Global Climate Change Examining the second hypothesis, there was an overall uptake of carbon of approximately 160 to 164 g C/m2 year for the planted wetland and 195 to 171 g C/m2 year for the unplanted wetland in 2010 and 2011, suggesting that these sites are acting as carbon sinks. Soil carbon sequestration rates measured in the two wetlands were 181193 g C/m2 year (with organic carbon accounting for 153-166 g C/m2 year) 10-years after creation and 219-266 g C/m2 year 15-years after creation, suggesting that this study's results with mesocosm chambers are reasonably accurate (Anderson and Mitsch 2006; Mitsch et al. 2012). Both of these wetlands were acting as carbon sinks. Examining the 98 ratio of the rate of carbon sequestration to the rate of methane emissions, however, a simple calculation shows that the planted wetland is acting as a sink of climate radiative forcing and the unplanted wetland is acting as a source of climate radiative forcing (Mitsch et al. 2012). When the decay of methane is accounted in the atmosphere, both wetlands were shown to be net radiative sinks (Mitsch et al. in press). A study of a natural wetland in Ohio showed lower carbon sequestration rates, with an average of 140 ± 16 g C/m2 year in riverine wetlands (Bernal and Mitsch 2012). Whiting and Chanton (2001) and Mitsch et al. (in press) have found that the wetlands they studied acted as carbon sinks, but taking into account the greenhouse warming potential of CO2 and CH4, the wetlands were still contributing to the greenhouse effect. However, it is predicted that over the long term (approximately 100 to 500 years for Whiting and Chanton 2001; 300 years or less for Mitsch et al. in press), the wetlands will act as carbon sinks and will mitigating the greenhouse effect. Future increases in temperature are likely to have an impact on the balance of gaseous carbon emissions within wetlands and may even turn previous carbon sinks into carbon sources. YvonDurocher et al. (2011) found that with an increase in 4 ºC, the fraction of gross primary productivity being released as CH4 increased by approximately 20%. In the short term, wetland creation may be a means of mitigating global climate change (Burkett and Kusler 2000; Badiou et al. 2011). Created wetlands have low soil organic matter after creation, compared to natural wetlands (Hossler and Bouchard 2010). The two experimental wetlands at the ORW have seen an increase in soil carbon from 16 g/kg of soil in 1993 pre-wetland creation to 36 g/kg of soil in the planted wetland and 46 99 g/kg of soil in the unplanted wetland in 2009 within the upper soil layers (Mitsch et al. 2012). As time passes, soil organic matter increases, with soil development proceeding faster under increased inundation (Craft et al. 2002). Carbon sequestration rates in newly created wetlands have been shown to be higher than natural wetlands (Mitra et al. 2005; Euliss et al. 2006; Mitsch et al 2012). Badiou et al. (2011) suggests that newly created prairie pothole wetlands may act as carbon sinks even when accounting for methane emissions due to the high rate of carbon sequestration seen after wetland creation. The type of wetland created will likely determine the ability of the wetland to sequester carbon. Peatlands exhibit slow carbon sequestration after creation and show net emissions of greenhouse gases due to the rate of decomposition of new peat, while coastal wetlands are likely to have high rates of carbon sequestration due to the constant burial of sediments (Zedler and Kercher 2005) and almost no methane emissions. The carbon balance in temperate freshwater wetlands likely falls somewhere between that of peatlands and coastal marshes due to both high carbon sequestration and methane emissions in temperate freshwater wetlands. When creating or restoring a wetland, it may be possible to enhance the ability of a wetland to act as a carbon sink through a combination of controlling the amount of open water and species present. Since there was no difference in methane emissions based on plots, yet there was higher gross primary productivity rates for plots with species that had high net primary productivity, a wetland composed of highly productive species will likely have higher amounts of overall carbon uptake. Additionally, open water plots had lower gross primary productivity rates, yet similar rates of daily 100 respiration compared to the vegetated plots, so reducing the amount of open water in a wetland may also increase overall carbon uptake. There was little variability in hydrology during this study, so differences in gross primary productivity, respiration, and methane emissions relating to hydrology was not examined. Future studies examining the effects of variations in water depth and flow rate through the wetland on carbon uptake and emissions may provide valuable insights into ecosystem processes in a wider range of wetlands, as well as under future climatic conditions that may have altered precipitation rates due to global climate change. 4.6 References Aber, J.D., & Melillo, J.M., 2001. Terrestrial ecosystems (2nd ed.). Harcourt Academic Press: San Diego, CA. pp. 34-36, 93-111. Altor, A.E., & Mitsch, W.J., 2008. Pulsing hydrology, methane emissions, and carbon dioxide fluxes in created marshes: A 2-year ecosystem study. Wetlands 28, 423438. Anderson, C.J., & Mitsch, W.J., 2006. Sediment, carbon, and nutrient accumulation at two 10-year-old created riverine marshes. Wetlands 26, 779-792. Badiou, P., McDougal, R., Pennock, D., & Clark, B., 2011. Greenhouse gas emissions and carbon sequestration potential in restored wetlands of the Canadian prairie pothole region. Wetland Ecology and Management 19, 237-256. Bernal, B., Mitsch, W.J., 2012. Comparing carbon sequestration in temperate freshwater wetland communities. Global Change Biology in press, doi: 10.1111/j.1365- 101 2486.2011.02619.x. Bonneville, M.C., Strachan, I.B., Humphreys, E.R., & Roulet, N.T., 2008. Net ecosystem CO2 exchange in a temperate cattail marsh in relation to biophysical properties. Agricultural and Forest Meteorology 148, 69-81. Bridgham, S.D., Megonigal, J.P., Keller, J.K., Bliss, N.B., & Trettin, C., 2006. The carbon balance of North American wetlands. Wetlands 26, 889-916. Brix, H., Sorrell, B.K., & Lorenzen, B., 2001. Are Phragmites-dominated wetlands a net source or net sink of greenhouse gases?. Aquatic Botany 69, 313-324. Burkett, V., & Kusler, J., 2000. Climate change: Potential impacts and interactions in wetlands of the United States. Journal of the American Water Resources Association 38, 313-320. Chanton, J.P., Bauer, J.E., Glaser, P.A., Siegel, D.I., Kelley, C.A., Tyler, S.C., Romanowicz, E.H., & Lazrus, A., 1995. Radiocarbon evidence for the substrates supporting methane formation within northern Minnesota peatlands. Geochimica et Cosmochimica Acta 59, 3663-3668. Cornell, J.A., Craft, C.B., & Megonigal, J.P., 2007. Ecosystem gas exchange across a created salt marsh chronosequence. Wetlands 27, 240-250. Craft, C., Broome, S., & Campbell, C., 2002. Fifteen years of vegetation and soil development after brackish-water marsh creation. Restoration Ecology 10, 248258. Dash, M.C., & Dash, S.P., 2009. Fundamentals of ecology (3rd edt.) Tata McGraw Hill, New Delhi. pg. 85 102 Drake, B.G., & Read, M., 1981. Carbon dioxide assimilation, photosynthetic efficiency and respiration of a Chesapeake Bay salt marsh. Journal of Ecology 69, 405-423. Euliss Jr., N.H., Gleason, R.A., Olness, A., McDougal, R.L., Murkin, H.R., Robarts, R.D., Bourbonniere, R.A., & Warner, B.G., 2006. North American prairie wetlands are important nonforested land-based carbon storage sites. Science of the Total Environment 361, 179-188. Funk, J.L., & Vitousek, P.M., 2007. Resource-use efficiency and plant invasion in lowresource systems. Nature 446, 1079-1081. Gedney, N., Cox, P.M., & Huntingford, C., 2004. Climate feedback from wetland methane emissions. Geophysical Research Letters 31, 1-4. Hossler, K., & Bouchard, V., 2010. Soil development and establishment of carbon-based properties in created freshwater wetlands. Ecological Applications 20, 539-553. Intergovernmental Panel on Climate Change (IPCC), 2007. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds.) Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Joabsson, A., Christensen, T.R., & Wallen, B., 1999. Vascular plant controls on methane emissions from norther peatforming wetlands. Trends in Ecology and Evolution 14, 385-388. Koh, H.S., Ochs, C.A., & Yu. K., 2009. Hydrologic gradient and vegetation controls on CH4 and CO2 fluxes in a spring-fed forested wetland. Hydrobiologia 630, 271- 103 286. Mitra, S., Wassmann, R., & Vlek, P.L.G., 2005. An appraisal of global wetland area and its organic carbon stock. Current Science 88, 25-33. Mitsch, W.J., Wu, X., Nairn, R.W., Weihe, P.E., Wang, N., Deal, R., & Boucher, C.E., (1998) Creating and restoring wetlands: A whole-ecosystem experiment in selfdesign. BioScience 48, 1019-1030. Mitsch, W.J., & Gosselink, J.G., 2007. Wetlands (4th edt.) pp. 319-327 John Wiley & Sons, Inc. Hoboken, New Jersey. Mitsch WJ, Zhang L, Stefanik KC, Nahlik AM, Anderson CJ, Bernal B, Song K (2012) Creating wetlands: A 15-year study of primary succession, water quality changes, and self-design. BioScience, 62, 237-250. Mitsch, W.J., Bernal, B., Nahlik, A.M., Mander, U., Zhang, L., Anderson, C.J., Jorgensen, S.E., & Brix. H., (In press) Wetlands, carbon, and climate change. Landscape Ecology. Nahlik, A.M., & Mitsch, W.J., 2010. Methane emissions from created riverine wetlands. Wetlands 30, 783-793. Nahlik, A.M., & Mitsch, W.J., 2011. Methane emissions from tropical freshwater wetlands located in different climate zones of Costa Rica. Global Change Biology 17, 1321-1334. Oechel, W.C., Vourlitis, G.L., Hastings, S.J., Zulueta, R.C., Hinzman, L., & Kane, D., 2000. Acclimation of ecosystem CO2 exchange in the Alaskan Arctic in response to decadal climate warming. Nature 406, 978-981. 104 The R Foundation for Statistical Computing, 2009. R version 2.10.1 (2009-12-14). Rasse, D.P., Stolaki, S., Peresta, G., & Drake, B.G., 2002. Patterns of canopy-air CO2 concentration in brackish wetlands: Analysis of a decade of measurements and the simulated effects on vegetation. Agricultural and Forest Meteorology 114, 59-73. Revsbech, N.P., Jorgensen, B.B, & Brix, O., 1981. Primary production of microalgae in sediments measured by oxygen microprofile, H14CO3- fixation, and oxygen exchange method. Limnology and Oceanography 26, 717-730. Rocha, A.V., & Goulden, M.L., 2009. Why is marsh productivity so high? New insights from eddy covariance and biomass measurement in a Typha marsh. Agricultural and Forest Meteorology 149, 159-168. Ruimy, A., Jarvis, P.G., Baldocchi, D.D., & Saugier, B., 1995. CO2 fluxes over plant canopies and solar radiation: a review. In: Advances in Ecological Research Vol. 26 (eds Begon M, Fitter AH), pp 1-68. Academic Press Limited, London. Running, S.W., Thornton, P.E., Nemani, R., & Glassy, J.M., 2000. Global terrestrial gross and net primary productivity from the earth observing system. In: Methods in Ecosystem Science (eds Sala OE, Jackson RB, Mooney HA, Howarth RW), pp 4457 Springer-Berlag, New York. Schutz, H., Seiler, W., & Conrad, R., 1990. Influence of soil temperature on methane emission from rice paddy fields. Biogeochemistry 11, 77-95. Segers, R., 1998. Methane production and methane consumption: a review of processes underlying wetland methane fluxes. Biogeochemistry 41, 23-51. Sha, C., Mitsch, W.J., Mander, U., Lu, J., Batson, J., Zhang, L., He, W., 2011. Methane 105 emissions from freshwater riverine wetlands. Ecological Engineering 37, 16-24. Smith, K.A., Dobbie, K.E., Ball, B.C., Bakken, L.R., Sitaula, B.K., Hansen, S., Brumme, R., Borken, W., Christensen, S., Prieme, A., Ffowler, D., Macdonald, J.A., Skiba, U., Klemedtsson, L., Kasimir-Klemedtsson, A., Degorska, A., & Orlanski, P., 2000. Oxidation of atmospheric methane in Northern European soils, comparison with other ecosystems, and uncertainties in the global terrestrial sink. Global Change Biology 6, 791-803. Streever, W.T., Genders, A.J., & Cole, M.A., 1998. A closed chamber CO2 flux method for estimating marsh productivity. Aquatic Botany 62, 33-44. Tuttle, C.L., Zhang, L., & Mitsch, W.J., 2007. Aquatic metabolism as an indicator of the ecological effects of hydrologic pulsing in flow-through wetlands. Ecological Indicators 8, 795-806. Whalen, S.C., 2005. Biogeochemistry of methane exchange between natural wetlands and the atmosphere. Environmental Engineering Science 22, 73-94. Whiting, G.J., & Chanton, J.P., 2001. Greenhouse carbon balance of wetlands: methane emissions versus carbon sequestration. Tellus Series B-Chemical and Physical Meteorology 53, 521-528. Yvon-Durocher, G., Montoya, J.M., Woodward, G., Jones, J.I., & Trimmer, M., 2011. Warming increases the proportion of primary production emitted as methane from freshwater mesocosms. Global Change Biology 17, 1225-1234. Zedler, J.B., & Kercher, S., 2005. Wetland resources: Status, trends, ecosystem services, and restorability. Annual Review of Environmental Resources 30, 39-74. 106 Table 4.1 Monthly average ± SE of environment variables over the course of the growing season in 2010 and 2011. Year Month Solar radiation (kcal/m2 day) Ambient temperature (°C) Water temperature (°C) Soil temperature (°C) Water depth (cm) 2010 May 3036 ± 420 21.7 ± 0.45 - - - June 4604 ± 224 27.3 ± 0.49 - - - July 3776 ± 167 30.5 ± 0.37 26.0 ± 0.31 24.8 ± 0.30 35.26 ± 0.12 August 3673 ± 117 22.6 ± 0.58 19.5 ± 0.31 20.4 ± 0.21 34.90 ± 0.02 September 2218 ± 186 12.4 ± 0.51 12.1 ± 0.47 13.6 ± 0.18 32.34 ± 0.44 April 2356 ± 415 15.8 ± 0.46 13.3 ± 0.28 13.9 ± 0.09 43.43 ± 0.89 May 4952 ± 274 25.4 ± 0.51 21.3 ± 0.33 18.9 ± 0.18 42.36 ± 0.63 June 4967 ± 430 25.4 ± 0.46 24.3 ± 0.32 22.5 ± 0.11 40.64 ± 3.62 July 5051 ± 270 30.3 ± 0.40 29.0 ± 0.23 26.7 ± 0.04 35.90 ± 0.05 August 4830 ± 153 25.9 ± 0.54 24.3 ± 0.26 23.1 ± 0.11 31.35 ± 0.15 September 2876 ± 262 20.1 ± 0.56 19.8 ± 0.29 20.1 ± 0.15 34.63 ± 0.23 2011 107 Table 4.2 p-values from ANOVA, linear regression models, and Kruskal-Wallis nonparametric test for the dependent and environmental variables. Significant p-values are in bold. Dependent variable Year Month Plant species Solar radiation Ambient temperature Soil temperature Water depth Gross Primary Productivity 0.997 <0.001 0.003 <0.001 0.002 0.001 0.408 Respiration 0.496 0.026 0.300 0.231 0.038 0.103 0.476 Methane 0.123 <0.001 0.319 0.181 0.4451 0.049 0.022 108 Figure 4.1 Diagram of flow-through metabolism chamber (FTMC) setup. The chamber consists of a base driven 10 cm into the soil, a PVC pipe frame, a plastic cover, an inflow pipe, and an outflow pipe. The large chamber stands 2.6 m tall including the base. The small chamber stands 1.6 m tall including the base. The inflow pipe has a multi-speed fan that forces air through the chamber, a pitot tube to measure air speed, and a sampling port. The inflow pipe is connected near the bottom of the clear chamber. Air is forced through the chamber and out of the outflow pipe at the top of the chamber. A second sampling port is located on the outflow pipe. 109 Figure 4.2 Average gross primary productivity for five different plant communities. The groups were open water, Phragmites australis, Scirpus fluviatilis, Sparganium eurycarpum, and Typha spp. Phragmites australis and Typha spp. were statistical different from the open water (p=0.012 and p=0.05, respectively). Phragmites australis was also statistical different from Scirpus fluviatilis (p=0.029). The lower end of each box represents the 25th percentile (lower quartile), while the upper end of each box represents to upper 75th percentile (upper quartile). The bold bar in each box is the median. The lines extending from each box indicate the minimum and maximum values that are within 1.5*interquartile range (upper minus lower quartile) of the upper or lower quartile. Outliers are represented by circles. 110 Figure 4.3 Monthly average and standard error of CO2 carbon fluxes of the five vegetation communities. Gross primary productivity (GPP) is represented by positive numbers indicating carbon uptake, while respiration is represented by negative numbers indicating carbon release. Peak gross primary productivity occurred in June of 2010 and in July of 2011. 111 Figure 4.4 Monthly median methane emissions from all five vegetation communities. April was statistically different than June (p<0.001) and July (p=0.001), while September was statistical different than June (p=0.004). Error bars represent the first and third quantiles of the data for each month. 112 Figure 4.5 Carbon uptake and emission as CO2 in relation to solar radiation and temperature. There was a significant difference in gross primary productivity due to solar radiation (p<0.001), with increased solar radiation causing an increase in gross primary productivity. Ambient temperature caused significant changes in respiration, with respiration increasing with ambient temperature (p=0.038). 113 Chapter 5: Conclusions 1) Vegetation structure in created and restored wetlands is influenced by time and initial creation techniques such as planting. Structural characteristics, such as species richness and floristic quality assessment index scores tend to decrease with age of the wetland. Planting was beneficial in regards to structural characteristics, with the planted wetland having higher species richness, floristic quality, and a smaller area occupied by invasive species than the unplanted wetland. 2) Vegetation function in created and restored wetlands also seems to be influenced by time and initial creation techniques such as planting, but to a lesser extent than was seen for vegetation structure. Aboveground net primary productivity tended to increase with age and the unplanted wetland had higher aboveground net primary productivity than the planted wetland. Belowground net primary productivity, total net primary productivity, and functional group composition were not affected by planting. 114 3) Vegetation community type plays an important role in the gross primary productivity and the net ecosystem exchange of carbon in wetlands. Species with higher net primary productivity tended to have higher gross primary productivity measurements than open water habitat and a macrophyte species with lower net primary productivity. Respiration and methane emissions were not influenced by the species present. Recommendations Based on the findings from the three chapters, six recommendations are given for wetland creation and restoration projects to help improve monitoring techniques, success rates, and carbon sequestration of created and restored wetlands. Extend monitoring time frames to 10-15 years to allow the structural characteristics of the wetland to stabilize before determining success. Monitor trends in the succession of functional groups to help determine if the mitigation wetlands are functionally equivalent to natural wetlands. Aim for median levels of aboveground net primary productivity within emergent zones for enhanced diversity. Vegetation planting may be beneficial even in riverine wetlands where outside propagules are introduced to the system via hydrochory and atmospheric fluxes. This may improve the structural vegetation characteristics of the site by increasing species diversity and quality and may help limit invasives in the system. 115 Introduce vegetation that has high productivity and high carbon use efficiency to increase the amount of atmospheric carbon fixation and increase the amount of carbon available for sequestration in the system. Reduce the amount of open water if increased carbon fixation is a desired goal. 116 References Aber, J.D., & Melillo, J.M., 2001. Terrestrial ecosystems (2nd ed.). Harcourt Academic Press: San Diego, CA. pp. 34-36, 93-111 Acton, W.T., 2004. A Monitoring and Management Report Year Four for the Ohio Wetland Foundation Wetland Mitigation Bank at the Slate Run Metropark Pickaway County, Ohio. Geotechnical Consultants Inc., Westerville, OH. Ahn, C., & Dee, S., 2011. Early development of plant community in a created mitigation wetland as affected by introduced hydrologic design elements. Ecological Engineering 37, 1324–1333. Altor, A.E., & Mitsch, W.J. 2008. Pulsing hydrology, methane emissions, and carbon dioxide fluxes in created marshes: A 2-year ecosystem study. Wetlands 28, 423438. Anderson, C.J., & Mitsch, W.J. 2006. Sediment, carbon, and nutrient accumulation at two 10-year-old created riverine marshes. Wetlands 26, 779-792. Andreas, B.K., Mack, J.J., & McCormac, J.S., 2004. Floristic Quality Assessment Index (FQAI) for Vascular Plants and Mosses for the State of Ohio. Ohio Environmental Protection Agency, Division of Surface Water, Wetland Ecology Group, Columbus, OH, 219 pp. Atkinson, R.B., Perry, J.E., & Cairns Jr., J., 2005. Vegetation communities of 20-year-old 117 created depressional wetlands. Wetland Ecology and Management 13, 469–478. AOAC International, 2002. AOAC official method 990.03 Protein (crude) in animal feed combustion method. Official Methods of Analysis AOAC International 17th edn. (eds. W. Horwitz), Ch4 pp. 26-27. AOAC International, Gaithersburg, MD, USA. Badiou, P., McDougal, R., Pennock, D., & Clark, B., 2011. Greenhouse gas emissions and carbon sequestration potential in restored wetlands of the Canadian prairie pothole region. Wetland Ecology and Management 19, 237-256. Balcombe, C.K., Anderson, J.T., Fortney, R.H., Rentch, J.S., Grafton, W.M., & Kordek, W.S., 2005. A comparison of plant communities in mitigation and reference wetlands in the Mid Appalachians. Wetlands 25, 130–142. Bantilan-Smith, M., Bruland, G.L., MacKenzie, R.A., Henry, A.R., & Ryder, C.R., 2009. A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai’i. Wetlands 29, 1023–1035. Bernal, B., & Mitsch, W.J., 2012. Comparing carbon sequestration in temperate freshwater wetland communities. Global Change Biology, in press, doi: 10.1111/j.1365-2486.2011.02619.x. Bonneville, M.C., Strachan, I.B., Humphreys, E.R., & Roulet, N.T., 2008. Net ecosystem CO2 exchange in a temperate cattail marsh in relation to biophysical properties. Agricultural and Forest Meteorology 148, 69-81. Boutin, C., & Keddy, P.A., 1993. A functional classification of wetland plants. Journal of Vegetation Science 4, 591–600. Bridgham, S.D., Megonigal, J.P., Keller, J.K., Bliss, N.B., & Trettin, C., 2006. The 118 carbon balance of North American wetlands. Wetlands 26, 889-916. Brinson, M.M.,1993. A hydrogeomorphic classification for wetlands. In: Technical Report WRP-DE-4. U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS. Brinson, M.M., & Rheinhardt, R., 1996. The role of reference wetlands in functional assessment and mitigation. Ecological Applications 6, 69–76. Brix, H., Sorrell, B.K., & Lorenzen, B., 2001. Are Phragmites-dominated wetlands a net source or net sink of greenhouse gases?. Aquatic Botany 69, 313-324. Bruland, G.L., & Richardson, C.J., 2005. Spatial variability of soil properties in created, restored, and paired natural wetlands. Soil Science Society of America Journal 69, 273–284. Burkett, V., & Kusler, J., 2000. Climate change: Potential impacts and interactions in wetlands of the United States. Journal of the American Water Resources Association 38, 313-320. Campbell, D.A., Cole, C.A., & Brooks, R.P., 2002. A comparison of created and natural wetlands in Pennsylvania, USA. Wetland Ecology and Management 10, 41–49. Catford, J.A., Daehler, C.C., Murphy, H.T., Sheppard, A.W., Hardesty, B.D., Westcott, D.A., Rejmánek, M., Bellingham, P.J., Pergl, J., Horvitz, C.C., & Hulme, P.E. 2012. The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management. Perspectives in Plant Ecology, Evolution and Systematics, http://dx.doi.org/10.1016/j.ppees.2011.12.002 Chanton, J.P., Bauer, J.E., Glaser, P.A., Siegel, D.I., Kelley, C.A., Tyler, S.C., 119 Romanowicz, E.H., & Lazrus, A., 1995 Radiocarbon evidence for the substrates supporting methane formation within northern Minnesota peatlands. Geochimica et Cosmochimica Acta 59, 3663-3668. Choi, Y.D., 2004 Theories for ecological restoration in changing environment: Toward a 'futuristic' restoration. Ecological Research 19, 75-81. Cole, C.A., & Shafer, D., 2002. Section 404 wetland mitigation and permit success criteria in Pennsylvania, USA, 1986–1999. Environmental Management 30, 508– 515. Cornell, J.A., Craft, C.B., & Megonigal, J.P., 2007. Ecosystem gas exchange across a created salt marsh chronosequence. Wetlands 27, 240-250. Craft, C., Broome, S., & Campbell, C., 2002. Fifteen years of vegetation and soil development after brackish-water marsh creation. Restoration Ecology 10, 248258. Dahl, T.E., 1990. Wetlands Losses in the United States 1780s to 1980s. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC, l3 pp. Dash, M.C., & Dash, S.P., 2009. Fundamentals of ecology (3rd edt.) Tata McGraw Hill, New Delhi. pg. 85 Davey Resource Group, 2007a. Monitoring and Management Report, Sandy Ridge Wetlands Mitigation Bank, North Ridgeville, Ohio. Davey Resource Group, Kent, OH. Davey Resource Group, 2007b. Year Two Wetlands Monitoring and Management Report, Trumbull Creek Wetlands Mitigation Bank Phase 2 North and South, 120 Thompson Township Geauga County and Trumbull Township Ashtabula County, Ohio. Davey Resource Group, Kent, OH. Davey Resource Group, 2007c. Year Five Monitoring and Management Report Trumbull Creek Wetlands Mitigation Bank Phase 1, Thompson Township Geauga Count and Trumbull Township Ashtabula County. Davey Resource Group, Kent, Ohio. De Deyn, G.B., Cornelissen, J.H.C., & Bardgett, R.D. 2008 Plant functional traits and soil carbon sequestration in contrasting biomes. Ecology Letters 11, 516-531. Diaz, S., & Cabido, M., 2001. Vive la difference: plant functional diversity matters to ecosystem processes. Trends in Ecology and Evolution 16, 646-655. Drake, B.G., & Read, M., 1981. Carbon dioxide assimilation, photosynthetic efficiency and respiration of a Chesapeake Bay salt marsh. Journal of Ecology 69, 405-423. Elifritz, B.F., & Fennessy, M.S., 1999. A comparison of natural and constructed wetlands using the floristic quality assessment index. In: Olentangy River Wetland Research Park Annual Report 1998. The Ohio State University, Columbus, pp. 69–73. Environmental Law Institute, 2002,.July. Banks and Fees: The Status of Off-site Wetland Mitigation in the United States. Washington, DC, Environmental Law Institute, www.eli.org/Program Areas/WMB. Euliss Jr., N.H., Gleason, R.A., Olness, A., McDougal, R.L., Murkin, H.R., Robarts, R.D., Bourbonniere, R.A., & Warner, B.G., 2006. North American prairie wetlands are important nonforested land-based carbon storage sites. Science of 121 the Total Environment 361, 179-188. Fahey, T.J. & Knapp, A.K. (edts.) 2007. Principles and stanrds for measuring primary production. Oxford university press. Fennessey, S., & Roehrs, J., 1997. A Functional Assessment of Mitigation Wetlands in Ohio: Comparisons With Natural Systems. Ohio Environmental Protection Agency Division of Surface Waters, Columbus, OH. Fraser, L.H., & Karnezis, J.P., 2005. A comparative assessment of seedling survival and biomass accumulation for fourteen wetland plant species grown under minor water-depth differences. Wetlands 25, 520–530. Funk, J.L., Cleland, E.E., Suding, K.N., & Zavaleta, E.S. 2008. Restoration through reassembly: plant traits and invasion resistance. Trends in Ecology & Evolution 23, 695–703. Gedney, N., Cox, P.M., & Huntingford, C., 2004. Climate feedback from wetland methane emissions. Geophysical Research Letters 31, 1-4. Grime, J.P., 1979. Plant Strategies and Vegetation Processes. John Wiley and Sons, New York, NY. Gutrich, J.J., Taylor, K.J., & Fennessy, M.S., 2009. Restoration of vegetation communities of created depressional marshes in Ohio and Colorado (USA): the importance of initial effort for mitigation success. Ecological Engineering 35, 351–368. Hossler, K., & Bouchard, V., 2010. Soil development and establishment of carbon-based properties in created freshwater marshes. Ecological Applications 20, 539-553. 122 Intergovernmental Panel on Climate Change (IPCC), 2007. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds.) Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Jampeetong, A., Brix, H., & Kantawanichkul, S., 2012. Effects of inorganic nitrogen forms on growth, morphology, nitrogen uptake capacity and nutrient allocation of four tropical aquatic macrophytes (Salvinia cucullata, Ipomoea aquatica, Cyperus involucratus, and Vetiveria zizanioides). Aquatic Botany 97, 10-16. Jenkins, J.C., Chojnacky, D.C., Heath, L.S., & Birdsey, R.A., 2003. National-scale biomass estimators for United States tree species. Forest Science 49, 12-35. Joabsson, A., Christensen, T.R., & Wallen, B., 1999. Vascular plant controls on methane emissions from norther peatforming wetlands. Trends in Ecology and Evolution 14, 385-388. Johnson, S.A., 1998. Effects of hydrology and plant introduction techniques on firstyear macrophyte growth in a newly created wetland. Thesis. The Ohio State University, Columbus, OH. Keddy, P., Fraser, L.H., & Wisheu, I.C., 1998. A comparative approach to examine competitive response of 48 wetland plant species. Journal of Vegetation Science 9, 777–786. Koh, H.S., Ochs, C.A., & Yu. K., 2009. Hydrologic gradient and vegetation controls on CH4 and CO2 fluxes in a spring-fed forested wetland. Hydrobiologia 630, 271- 123 286. Lenssen, J., Menting, F., van der Putten, W., & Blom, K., 1999. Control of plant species richness and zonation of functional groups along a freshwater flooding gradient. Oikos 86, 523–534. LePage, B.A., 2011. Wetlands: A Multidisciplinary Perspective. Springer, Netherlands. Leps, J., & Smilauer, P., 2003. Multivariate Analysis of Ecological Data using CANOCO. Cambridge University Press, Cambridge, United Kingdom. Lopez, R.D., & Fennessy, M.S., 2002. Testing the floristic quality assessment index as an indicator of wetland condition. Ecological Applications 12, 487–497. Marble, A.D., 1992. A guide to wetland functional design. Pp 1-14, CRC Press, Boca Raton, FL. Matthews, J.W., 2008. Restoration progress and plant community development in compensatory mitigation wetlands. Dissertation Abstracts International. 69, 272. Matthews, J.W., Spyreas, G. & Endress, A.G. 2009. Trajectories of vegetation-based indicators used to assess wetland restoration progress. Ecological Applications 19, 2093-2107. Matthews, J.W., & Endress, A.G., 2010. Rate of succession in restored wetlands and the role of site context. Applied Vegetation Science 13, 346–355. McCune, B., & Grace, J.B., 2002. Analysis of Ecological Communities. MJM Software Design, Glenedon Beach, OR. McGill, B.J., Enquist, B.J., Weiher, E., & Westoby ,M. 2006. Rebuilding community 124 ecology from functional traits. Trends in Ecology and Evolution,21, 178-185. Middleton, E.L., Bever, J.D., & Schultz, P.A. 2010 The effects of restoration methods on the quality of the restoration and resistance to invasion by exotics. Restoration Ecology 18, 181-187. Mitra, S., Wassmann, R., Vlek, P.L.G., 2005. An appraisal of global wetland area and its organic carbon stock. Current Science 88, 25-33. Mitsch, W.J., & Wilson, R.F., 1996. Improving the success of wetland creation and restoration with know-how, time, and self-design. Ecological Applications 6, 77– 83. Mitsch, W.J., Wu, X., Nairn, R.W., Weihe, P.E., Wang, N., Deal, R., & Boucher, C.E., 1998. Creating and restoring wetlands: a whole-ecosystem experiment in selfdesign. BioScience 48, 1019–1030. Mitsch, W.J., Day Jr., J.W., Gilliam, J.W., Groffman, P.M., Hey, D.L., Randall, G.W., & Wang, N., 2001. Reducing nitrogen loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to counter a persistent large-scale ecological problem. BioScience 51, 373-388 Mitsch, W.J., Wang, N., Zhang, L., Deal, R., Wu, X., & Zuwerink, A., 2005a. Using ecological indicators in a whole-ecosystem wetland experiment. In: Handbook of Ecological Indicators for Assessment of Ecosystem Health. CRC Press, Boca Raton, FL, pp. 211–236. Mitsch, W.J., Zhang, L., Anderson, C.J., Altor, A., & Hernandez, M., 2005b. Creating riverine wetlands: ecological succession, nutrient retention, and pulsing effects. 125 Ecological Engineering 25, 510–527. Mitsch, W.J, Anderson, C.J., Hernandez, M.E.& Zhang, L., 2006. Net primary productivity of macrophyte communities in the experimental marshes after twelve growing seasons. Wilma H. Schiermeier Olentangy River Wetland Research Park Annual Report 2005, 107-110. Mitsch, W.J. & Day Jr., J.W., 2006. Restoration of wetlands in the Mississippi-OhioMissouri (MOM) River Basin: Experience and needed research. Ecological Engineering 26, 55-69. Mitsch, W.J., & Gosselink, J.G., 2007. Wetlands, 4th ed. John Wiley & Sons, Inc., Hoboken, NJ. Mitsch, W.J., Zhang, L., Stefanik, K.C., Nahlik, A.M., Anderson, C.J., Bernal, B., Hernandez, M., & Song, K., 2012. Creating wetlands: primary succession, water quality changes, and self-design over 15 years. BioScience 62, 237-250. Mitsch, W.J., Bernal, B., Nahlik, A.M., Mander, U., Zhang, L., Anderson, C.J., Jorgensen, S.E., & Brix. H., (In press) Wetlands, carbon, and climate change. Landscape Ecology. Muzika, R.M., Gladden, J.B., & Haddock, J.D., 1987. Structural and functional aspects of succession in south-eastern floodplain forests following a major disturbance. American Midland Naturalist 117, 1–9. Nahlik, A.M., & Mitsch, W.J., 2010. Methane emissions from created riverine wetlands. Wetlands 30, 783-793. Nahlik, A.M., & Mitsch, W.J., 2011. Methane emissions from tropical freshwater 126 wetlands located in different climate zones of Costa Rica. Global Change Biology 17, 1321-1334. National Research Council, 2001. Compensating for Wetland Losses under the Clean Water Act, Committee on Mitigating Wetland Losses. National Academies Press, Washington, DC. Niswander, S.F., & Mitsch, W.J., 1995. Functional analysis of a two-year-old created in-stream wetlands: hydrology, phosphorus retention, and vegetation survival and growth. Wetlands 15, 212–225. Oechel, W.C., Vourlitis, G.L., Hastings, S.J., Zulueta, R.C., Hinzman, L., & Kane, D. 2000. Acclimation of ecosystem CO2 exchange in the Alaskan Arctic in response to decadal climate warming. Nature 406, 978-981. Ohio Agricultural Research and Development Center (OARDC), 2012. Methods and References. STAR Lab, http://www.oardc.ohio-state.edu/starlab/t08_pageview3/References.htm. The R Foundation for Statistical Computing, 2009. R Version 2.10.1 (2009-12-14). Rasse, D.P., Stolaki, S., Peresta, G., & Drake, B.G., 2002. Patterns of canopy-air CO2 concentration in brackish wetlands: Analysis of a decade of measurements and the simulated effects on vegetation. Agricultural and Forest Meteorology 114, 59-73. Reddy, K.R. & DeLaune, R.D., 2008. Biogeochemistry of wetlands science and applications. CRC Press, Boca Raton, FL. Reed, P.B., 1988. National list of plant species that occur in wetlands: Northeast (Region 1). U.S. Fish and Wildlife Service Biological Report 88(26.1). 127 Reinartz, J.A. & Warne, E.L. 1993. Development of vegetation in small created wetlands in southeast Wisconsin. Wetlands 13, 153-164. Reiss, K.C., Hernandez, E., & Brown, M.T., 2009. Evaluation of permit success in wetland mitigation banking: a Florida case study. Wetlands 29, 907–918. Revsbech, N.P., Jorgensen, B.B, & Brix, O., 1981. Primary production of microalgae in sediments measured by oxygen microprofile, H14CO3- fixation, and oxygen exchange method. Limnology and Oceanography 26, 717-730. Rocha, A.V., & Goulden, M.L., 2009. Why is marsh productivity so high? New insights from eddy covariance and biomass measurement in a Typha marsh. Agricultural and Forest Meteorology 149, 159-168. Ruimy, A., Jarvis, P.G., Baldocchi, D.D., & Saugier, B., 1995. CO2 fluxes over plant canopies and solar radiation: a review. In: Advances in Ecological Research Vol. 26 (eds Begon M, Fitter AH), pp 1-68. Academic Press Limited, London. Running, S.W., Thornton, P.E., Nemani, R., & Glassy, J.M. 2000. Global terrestrial gross and net primary productivity from the earth observing system. In: Methods in Ecosystem Science (eds Sala OE, Jackson RB, Mooney HA, Howarth RW), pp 4457 Springer-Berlag, New York. Sala, O.E., Jackson, R.B., Mooney, H.A., & Howarth, R.W., 2000. Methods in ecosystem science. Springer, New York. Salzman, J., & Thompson Jr., B.H., 2007. Environmental Law and Policy. Foundation Press, New York, NY. Schutz, H., Seiler, W., & Conrad, R., 1990. Influence of soil temperature on methane 128 emission from rice paddy fields. Biogeochemistry 11, 77-95. Segers, R., 1998. Methane production and methane consumption: a review of processes underlying wetland methane fluxes. Biogeochemistry 41, 23-51. Sha, C., Mitsch, W.J., Mander, U., Lu, J., Batson, J., Zhang, L., He, W., 2011. Methane emissions from freshwater riverine wetlands. Ecological Engineering 37, 16-24. Smith, K.A., Dobbie, K.E., Ball, B.C., Bakken, L.R., Sitaula, B.K., Hansen, S., Brumme, R., Borken, W., Christensen, S., Prieme, A., Ffowler, D., Macdonald, J.A., Skiba, U., Klemedtsson, L., Kasimir-Klemedtsson, A., Degorska, A., & Orlanski, P., 2000. Oxidation of atmospheric methane in Northern European soils, comparison with other ecosystems, and uncertainties in the global terrestrial sink. Global Change Biology 6, 791-803. Spieles, D.J., 2005. Vegetation development in created, restored, and enhanced mitigation wetland banks of the United States. Wetlands 25, 51–63. Spieles, D.J., Coneybeer, M., & Horn, J., 2006. Community structure and quality after 10 years in two central Ohio mitigation bank wetlands. Environmental Management 38, 837–852. Stefanik, K.C., & Mitsch, W.J., 2012. Structural and functional vegetation development in created and restored wetland mitigation banks of different ages. Ecological Engineering, 39,104-112. Streever, W.T., Genders, A.J., & Cole, M.A., 1998. A closed chamber CO2 flux method for estimating marsh productivity. Aquatic Botany 62, 33-44. Suding, K.N., & Cross, K.L., 2006. The dynamic nature of ecological systems: Multiple 129 states and restoration trajectories. Foundations of Restoration Ecology (eds D.A. Falk, M.A. Palmer, & J.B. Zedler) pp. 190-209 Island Press, Washington, D.C. Svengsouk, L.J., & Mitsch, W.J., 2001. Dynamics of mixtures of Typha latifolia and Schoenoplectus tabernaemontani in nutrient enrichment wetland experiments. American Midland Naturalist 145, 309-324. Tanner, C.C., 1996. Plants for constructed wetland treatment systems – A comparison of the growth and nutrient uptake of eight emergent species. Ecological Engineering 7, 59-83. ter Braak, C.J.F., & Smilauer, P., 2004. Canoco for Windows (Version 4.53). BiometricsPlant Research International, Wageningen, Netherlands. Tilman, D., 1986. Resources, Competition, and the Dynamics of Plant Communities. Plant Ecology. Blackwell Scientific, Boston, MA. Tilman, D., Knops, J., Wedin, D., Reich, P., Ritchie, M., & Siemann, E., 1997. The influence of functional diversity and composition on ecosystem processes. Science 277, 1300–1302. Thursby, G.B., Chintala, M.M., Stetson, D., Wigand, C., & Champlin, D.M., 2002. A rapid, non destructive method for estimating aboveground biomass of salt marsh grasses. Wetlands 22, 626–630. Tuttle, C.L., Zhang, L., & Mitsch, W.J., 2007. Aquatic metabolism as an indicator of the ecological effects of hydrologic pulsing in flow-through wetlands. Ecological Indicators 8, 795-806. United States Department of Agriculture Natural Resources Conservation Service. Web 130 soil survey. http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey. aspx (accessed 23.02.11). van der Valk, A.G., Toth, L.A., Gibney, E.B., Mason, D.H., & Wetzel, P.R., 2009. Potential propagule sources for reestablishing vegetation on the floodplain of the Kissimmee river, Florida, USA. Wetlands 29, 976–987. Walker, L.R. & del Moral, R., 2008. Transition dynamics in succession: Implications for rates, trajectories, and restoration. New Models for Ecosystem Dynamics and Restoration (eds K. Suding & R.J. Hobbs), pp. 33-49 , Island Press, Washington, D.C. Whalen, S.C., 2005. Biogeochemistry of methane exchange between natural wetlands and the atmosphere. Environmental Engineering Science 22, 73-94. White, P.S. & Jentsch, A. 2001. The search for generality in studies of disturbance and ecosystem dynamics. Progress in Botany 62, 399-450 Whiting, G.J., & Chanton, J.P., 2001. Greenhouse carbon balance of wetlands: methane emissions versus carbon sequestration. Tellus Series B-Chemical and Physical Meteorology 53, 521-528. Windham, L., 2001. Comparison of biomass production and decomposition between Phragmites australis (common reed) and Spartina patens (salt hay grass) in brackish tidal marshes of New Jersey, USA. Wetlands 21, 179–188. Wright, J.P. & Jones, C.G., 2004. Predicting effects of ecosystem engineers on patchscale species richness from primary productivity. Ecology 85, 2071-2081. Young, S.L., Barney, J.N., Kyser, G.B., Jones, T.S. & DiTomaso, J.M., 2009. 131 Functionally similar species confer greater resistance to invasion: Implications for grassland restoration. Restoration Ecology 17, 884-892. Yvon-Durocher, G., Montoya, J.M., Woodward, G., Jones, J.I., & Trimmer, M., 2011. Warming increases the proportion of primary production emitted as methane from freshwater mesocosms. Global Change Biology 17, 1225-1234. Zedler, J.B., 2000. Progress in wetland restoration and ecology. Trends in Ecology and Evolution 15, 402-407. Zedler, J.B., & Kercher, S., 2005. Wetland resources: Status, trends, ecosystem services, and restorability. Annual Review of Environmental Resources 30, 39-74. 132 Appendix A: In-depth Site Descriptions Hebron Hebron mitigation bank is located at the Hebron State Fish Hatchery in Hebron, Licking County, Ohio and consists of two created/restored wetlands. The mitigation bank is located in the Bell Run sub-watershed, code 050400060406. The larger of the two wetlands is located at 39° 56’25”N, 82° 30’19”W and is currently dominated by marsh vegetation. Encroachment of shrub and tree species is evident around the perimeter of the wetland. The original mitigation goal of this wetland was for it to develop into a swamp. The smaller wetland is located at 39° 56’28”N, 82° 30’33”W and is a Typha spp. marsh. According to Spieles et al. (2006) the wetlands were constructed on a Luray silty clay loam soil, with plantings at the site consisting of only shrub and tree species; no herbaceous vegetation plantings occurred at this site. Both wetlands are depressional wetlands whose main water input is precipitation and thus experiences vertical fluctuation of the water level (Brinson 1993). The site is managed by the Ohio Department of Natural Resources, Division of wildlife. Little physical management of the smaller wetland occurs, however, herbicides are sprayed within the larger wetland to reduce the amount of the invasive species Phalaris arundinacae. A section of the larger wetland is flooded during early September to attract water fowl for hunting purposes. 133 Sandy Ridge Sandy Ridge mitigation bank is located at Sandy Ridge Reservation Lorain County Metropark, North Ridgeville, Ohio. The site is located in the Black River and French Creek subwatersheds, codes 041100010602 and 041100010601 respectively. Three connected wetland cells make up the site. Only one of the cells, coordinates 41° 23’ 32.94” N 82° 03’ 3.99” W, was included in the study due to restricted access to prevent the disruption of a nesting bald eagle pair. This cell was dominated by herbaceous vegetation with a few trees located in upland islands within the wetland cell. The main soil type at this site is Fitchville silt loam. The wetland at this site is depressional and experiences water input from both precipitation and surface flow. The water level mainly undergoes vertical fluctuation, but is designed to allow for some unidirectional flow when desired (Brinson 1993). The site is maintained by the Lorain County Metroparks. Management at the site includes mowing and spraying of Phalaris arundinacea and lowering the water level of the wetland during the spring to prevent it from spilling over the banks and onto the public walking trail. Slate Run Slate Run mitigation bank is located at Slate Run Wetlands Wildlife Refuge Slate Run Metropark, just south of Canal Winchester in Pickaway County, Ohio. The site is located in the Big Run and Little Walnut Creek sub-watersheds, codes 050600011805 and 050600011804 respectively. Approximately a dozen wetlands are located at this site. Ultimately, four wetlands were sampled for inclusion in this study. Coordinates for these 134 sites were 39° 45’46”N 82° 51’59”W, 39° 45’41”N 82° 52’6”W, 39° 45’28”N 82° 51’59”W, and 39° 45’49”N 82° 51’49”W. All of these wetlands were dominated by herbaceous vegetation with some encroachment of shrub and trees species around the wetland borders. The main soil type at the site is Kokomo silty clay loam. All of the wetlands at this site are depressional. Two of the four wetlands examined experience mainly precipitation hydrologic inputs, while the remaining two experience both precipitation and groundwater inputs. The water levels within these wetlands undergo vertical fluctuation (Brinson 1993). The site is owned and managed by the Columbus and Franklin County Metropolitan Park District. Management of the site includes spraying and mowing for invasive species, as well as spraying/cutting of willow saplings within the wetlands. Five wetlands were initially to be included in the study, but chemical and physical removal of species (mowing) within the fifth wetland destroyed the majority of vegetation therein. Trumbull Creek Phase I Trumbull Creek mitigation bank Phase I is Located in Geauga and Ashtabula Counties within the Mill Creek subwatershed, code 041100040602. Three large wetland cells are located at this site, with the middle cell (coordinates 41°39’ 46.13” N 81° 00’ 33.00” W) being used for this study. The main soil types are Platea and Sheffield silt loam. The wetland is depressinal with mostly precipitation hydrologic inputs and experiences both vertical water fluctuation and during the rainy season, unidirectional flow as well (Brinson 1993). Seeding was done post construction in 2007. Adjustment 135 of water level and spraying has been used at the site to control invasive species and amount of open water at the site. Trumbull Creek Phase II Trumbull Creek Phase II is split up into a northern (coordinates 41° 39’ 53” N and 80° 59’ 48” W) and southern (coordinates 41° 39’ 48” N and 81° 00’ 0” W) section by state route 166 with little to no connectivity between the two sections. This site is located in Geauga and Ashtabula Counties, adjacent to Trumbull Creek Phase I. Trumbull Creek Phase II is located within Mill Creek (code: 041100040602) and Bronson Creek (code: 041100040502) subwatersheds. The site consists of over 100 small constructed basins that were designed to allow for water connectivity during the wet season. The soil at this site consists of Sheffield soils. All of the wetlands are depressional, mainly precipitation fed, and experience vertical fluctuation in the water levels (Brinson 1993). The site was planted with tree seedlings in 2005. Spraying has occurred at the site to reduce the amount of invasive vegetation, primarily Phalaris arundinacea. Olentangy River Wetland Research Park Two experimental wetlands, both one hectare in size, at the Olentangy River Wetland Research Park, Ohio State University, Columbus Ohio (coordinates 40º 01’ 12.33”N 83º 01’ 5.55”W) were used for this study. These wetlands were constructed in 1994 to be used for research and education. The site receives the majority of its hydrologic inputs from the Olentangy river via pump, which is set so that the flow rate 136 into the wetlands is proportional to the water depth of the river. This site is within the Mouth Olentangy River subwatershed (code: 050600011103). The soil type at this site is mostly Ross silt loam with some Eldean silt loam (Anderson et al. 2002). The wetlands used for this study are riverine wetlands whose main water source is unidirectional surface flow (Brinson 1993). As far as management goes, the largest controlled variable is the hydrology of the site. Over the course of this study, the water level has been maintained in accordance with water depth in the river. Little is done in terms of invasive species management; only occasional manual removal of Lythrum salicaria (purple loosestrife) occurs within the two experimental wetlands. Phragmites australis (common reed grass) is present in one of the experimental wetlands, but is not removed in order to maintain the integrity of an ongoing experiment dealing with wetland planting and succession. Calamus Swamp Calamus swamps is a natural kettle wetland west of Circleville in Pickaway County, Ohio. This wetland is surrounded by agricultural fields within the Lick River subwatershed (code: 050600020403). The site is owned by the Columbus Audubon Society and is open to the public. The site is used for bird watching and the walking trails. The soil at Calamus swamp is mainly Montgomery silty clay loam (USDA NRCS 2011). The wetland is a depressional wetland that is precipitation fed and experiences vertical water level fluctuation (Brinson 1993). No wetland maintenance occurs at the site. 137 Appendix B: Regression Equations Table B.1 Regression equations created for dominant species. y-biomass per stem, xaverage height of the stems within a sampling plot. After using the equation to find y, y is then multiplied by the number of stems in a plot to estimate ANPP of the species. Other equations were obtained from Johnson (1998) and Muzika et a. (1987). Species Biddens cernua Decodon verticallus Eleocharis a. Eleocharis obtusa Hypericum m. Juncus effusus Penthorum sedoides Phalaris arundinacae Phyla lanceolata Scirpus cyperinus Scirpus pungens Typha spp. Equation y = 0.0084x + 0.0139 y = 0.886x - 71.968 y = 0.0065x - 0.2201 y = 0.001x - 0.0025 y = 0.0136x - 0.4045 y = 0.0038x y = 0.0082x - 0.002 y = 0.0103x - 0.0197 y = 0.0096x - 0.013 y = 0.0933x - 2.0333 y = 0.0034x + 0.1135 y = 0.0472x + 9.2366 138 R2 R = 0.86 R2 = 0.85 R2 = 0.77 R2 = 0.67 R2 = 0.77 R2 = 0.73 R2 = 0.98 R2 = 0.97 R2 = 0.93 R2 = 0.73 R2 = 0.82 R2 = 0.75 2 Appendix C: Mitigation Bank and Reference Wetland Vegetation 139 Table C.1 Plant species found at each site over the course of the study from 2008-2010. Includes coefficient of conservatism and wetland indicator status for each species. Species Wetland Indicator Status C of C Hebron '08 '09 ORW '10 Abies balsamea Abutilon theophrasti (Medik.) UPL * Acalypha rhomboidea (Raf.) FAC- 0 Acalypha virginica (L.) FACU- 0 Acer negundo (L.) FAC+ 3 Acer rubrum (L.) FAC 2 Acer saccharinum (L.) FAC 3 Acer saccharum (Marshall) FACU- 5 Acer sp. OBL * Actaea alba (L.) UPL 7 Agrostis tenuis (Sibth.) FACU- * Alisma plantagoaquatica (L.) OBL 2 Alliaria petiolata FACU * Allium canadense FACU 2 '08 '09 Slate Run '08 '09 '10 X X X X X X X X '10 X X X X X X X X X X X X X X X X '08 '09 '10 X X X X X X X X X X X na Acorus calamus (L.) Sandy Ridge X X X X X X X X X X X X X X 140 X X X X X X X X X (L.) Ambrosia artemisiifolia (L.) FACU 0 X X X Ambrosia trifida (L.) FAC 0 X X X Andropogon gerardii (Vitman) FAC 5 Apocynum cannabinum (L.) FACU 1 Aristolochia serpentaria (L.) UPL 7 Artemisia vulgaris (L.) FACU- * Asclepias incarnate (L.) OBL 4 X X X Asclepias syriaca (L.) FACU- 1 X X X Asclepias tuberosa (L.) UPL 4 Asimina triloba ((L.) Dunal) FACU+ 6 Aster ericoides (L.) FACU 2 Aster lanceolatus (Willd.) FACW 3 Aster novaeangliae (L.) FACW- 2 Aster pilosus (Willd.) UPL 1 Aster praealtus (Poir.) FACW 6 Aster racemosus (Elliott) FACW 2 Aster sp. Aster umbellatus X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 3 141 X X X X X X X X X X X na FACW X X X X X (Mill.) Betula sp. na Bidens aristota ((Michx.)Brit ton) FACW- 4 Bidens cernua (L.) OBL 2 X X Bidens connata (Muhl. ex Willd.) FACW+ 3 X X Bidens coronata ((L.) Britton) OBL 3 X Bidens frondosa (L.) FACW 2 Bidens sp. X X X X X X X X X X X X X X X X X X X na Bidens vulgata (Greene) FACW 2 Boehmeria cylindrica ((L.) Sw.) FACW+ 4 Brasenia schreberi (J.F. Gmel.) OBL 7 Campsis radicans (L.) FAC 1 Carex bromoides (Schkuhr ex Willd.) FACW 7 Carex frankii (Kunth) OBL 2 Carex intumescens (Rudge) FACW+ 5 Carex lupilina (Muhl. ex Willd.) OBL 3 Carex lurida (Wahlenb.) 0BL 3 Carex tribuloides FACW+ 4 X X X X X X X 142 X X X X X X X X X X X X X X X X X X X (Wahlenb.) Carex sp. na X X Carex utriculata (Boott) OBL 7 Carex vulpinoidae (Michx.) OBL 1 Carpinus caroliniana (Walter) FAC 5 Carya glabra ((Mill.) Sweet) FACU- 5 Carya ovalis ((Wangenh.) Sarg.) UPL 5 Carya ovata ((Miller) K.Koch) FACU- 6 Cassia fasiculata (Michx.) FACU 3 Catalpa bignoniodes (Walter) UPL * Cepthalanthu s occidentalis (L.) OBL 6 Chrisanthem um leucanthemu m (L.) UPL * Cichorium intybus (L.) UPL * Cicuta bulbifera (L.) OBL 3 X Cicuta maculata (L.) OBL 3 X Cicuta sp. OBL na Cirscium altissimum ((L.) Hill) UPL 4 Cirscium arvense ((L.) Scop.) FACU * X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 143 X Convolvulus sepium (L.) FAC- 1 Cornus amomum (Mill.) FACW 2 Cornus florida (L.) FACU- 5 Cornus sp. X X X X X X X X X X X X X X X X X X na Cuscuta gronovii (Willd. Ex Schulte) FACW+ 3 Cuscuta sp. NA na Cyperus erythrorhizos (Muhl.) FACW+ 4 Cyperus esculentus (L.) FACW 0 Cyperus squarrosus (L.) FACW+ 3 Cyperus strigosus (L.) FACW 1 Daucus carota (L.) UPL * Decodon verticillutus ((L.)Elliott) OBL 6 Desmodium cuspidatum ((Muhl. ex Willd.) DC ex Loudon) UPL 4 Dianthus armeria (L.) OBL * Dipsacus sylvestris (L.) FACU- * Duchesnea indica ((Andrews) Focke) FACU- * Echinacea purpurea ((L.) Moench) UPL 6 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 144 X X X X X X X X X X X X X Echinochloa crusgali ((L.) P. Beauv.) FACU * X X X Echinochloa muricata ((P. Beauv.) Fernald) FACW+ 3 X X X Eleocharis acicularis ((L.) Roem. & Schult.) OBL 3 X X Eleocharis obtusa ((Willd.) Schult.) OBL 1 X X Eleocharis ovata ((Roth) Roem. & Schult.) OBL 9 X Eleocharis quadrangulat a ((Michx.) Roem. & Schult.) OBL 4 X X Elodia canadensis (Michx.) OBL 3 X X Epilobium coloratum (Biehler) OBL 1 X X X X X X X X X X X X Epilobium sp. na Equisetum sp. na Erechtites hieracifolia ((L.) Raf. ex DC.) FACU 2 Erigeron annuus ((L.) Pers.) FACU 0 Erigeron sp. X X X X X X FACW 6 Eupatorium hyssopifolium (L.) UPL 4 Eupatorium FACW 6 X X X X X X X X X X X X X X X X X X X X X X X X X na Eupatorium fistulosum (Barratt) X X X X X X X 145 maculatum (L.) Eupatorium perfoliatum (L.) FACW+ 3 Eupatorium serotinum (Michx.) FAC- 2 Festuca pratensis (Huds.) FACU- * Fragaria virginiana (Duchesne) FACU 1 Fraxinus americanus (L.) FACU 6 Fraxinus pennsylvanic a (Marshall) FACW 3 Galium sp. X X X na Galium asperllum (Michx.) OBL 4 Galium tinctorium ((L.) Scop.) OBL 4 Geum aleppicum (Jacq.) FAC 3 Geum laciniatum (Murray) FAC+ 2 Geum lanceolatum (Murray) FAC+ 5 X X Glechoma hederacea (L.) FACU * Gleditsia triacanthos (L.) FAC- 4 OBL 2 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X N a Geum sp. Glyceria striata ((Lam.) X X X X X X X X X X X X X X X 146 X X Hitchc.) Helenium autumnale (L.) FACW+ 4 Helianthus divaricatus (L.) UPL 4 Helianthus gigenteus (L.) FACW 6 Hemerocallis fulva ((L.)L.) UPL * Hibiscus laevis (All.) OBL 7 Hordem jubatum (L.) FAC 5 Hypericum canadense (L.) FACW 7 Hypericum mutilum (L.) FACW 3 Hypericum perforatum (L.) UPL * Impatiens capensis (Meerb.) FACW 2 X X Ipomoea puppurea ((L.) Roth) UPL * X X Iris sp. X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X na Juglans nigra (L.) FACU 5 Juncus canadensis (J. Gay ex Laharpe) OBL 4 X Juncus dudleyi (Wiegand) FACW- 3 X X X Juncus effuses (L.) FACW+ 1 X X X Juncus tenuis (Willd.) FAC- 1 Juncus FACW 3 X X X X X 147 X torreyi (Coville) Lathyrus palustris (L.) FACW+ 5 Leersia oryzoides ((L.) Sw.) OBL 1 X X X X X X X X X X X Lemna minor (L.) OBL 3 X X X X X X X X X X X Lespedeza violacea ((L.) Pers.) UPL 4 X X X X X Lillium sp. na Lindernia dubia ((L.) Pennell) OBL 2 Lobelia cardinalis (L.) FACW+ 5 Lobelia siphilitica (L.) FACW+ 3 X X X Lonicera maackii ((Rupr.) Maxim.) UPL * X X X Lonicera sp. X X X X X X na Lotus corniculatus (L.) FACU- * Ludwigia alternifolia (L.) FACW+ 3 Ludwigia palustris ((L.) Elliott) OBL 3 Lycopus americanus (Muhl. ex W.P.C. Barton) OBL 3 Lycopus sp. X X OBL 3 Lysimachia OBL * X X X X X X X X X X X X X X X X X X X X X X X X X X X X X na Lycopus uniflorus (Michx.) X X X X X X 148 X X nummularia (L.) Lythrum salicaria (L.) FACW+ * Mentha aravensis (L.) FACW 2 Mimulus ringens (L.) OBL 4 Morus rubra (L.) FACU 7 Nelumbo lutea (Willd.) OBL 7 Nuphar advena ((Aiton) W.T.Aiton) OBL 4 X X X Nymphaea odorata (Aiton) OBL 6 X X X Oenthera biennis (L.) FACU- 1 X X X Onoclea sensibilis (L.) FACW 2 Oxalis sp. X X X X X X X X X X X X X X X X X X X X X X X X X X FAC- 9 Oxalis stricta (L.) UPL 0 Panicum dichotomiflor um (Michx.) FACW- 0 Panicum virgatum (L.) FAC 4 Parthenociss us quinquefolia ((L.) Planch.) FACU 2 Penthorum sedoides (L.) OBL 2 Phalaris arundinacea (L.) FACW+ * Phaseolus UPL 3 X X X X X na Oxalis acetosella (L.) X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 149 polystachios ((L.) B.S.P.) Phleum pretense (L.) FACU * Phragmites australis ((Cav.) Trin.) FACW * X X X Phyla lanceolata ((Michx.)Gre ene) OBL 3 X X X Phytolacca americana (L.) FACU+ 1 Plantago major (L.) FACU * Platanus occidentalis (L.) FACW- 7 Poa palustris (L.) FACW 5 Podophyllum peltatum (L.) FACU 4 Polygonum coccineum X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Polygonum hydropiper (L.) OBL 1 Polygonum hydropiperoi des (Michx.) OBL 6 Polygonum lapathifolia (L.) FACW+ 1 Polygonum pennylvanica (L.) FACW 0 Polygonum persicaria (L.) FACW * Polygonum sagittatum (L.) OBL 2 Polygonum virginianum (L.) FAC 3 X X X X X 150 X X X X X X X Pontideria cordata (L.) OBL 6 Populus deltoides (W. Bartram ex Marshall) FAC 3 Populus tremuloides (Michx.) FACU Potamogeton natans (L.) Potamogeton pectinatus (L.) X X X X X X X X X X X X X X X X X X X X X X X X 2 X X X X X OBL 8 X X X OBL 2 X X Potamogeton sp. X X na X X X X Prenanthes altisima (L.) FACU- 4 Prunella vulgaris (L.) FACU+ 0 Quercus bicolor (Willd.) FACW+ 7 Quercus palustris (Muenchh.) FACW 5 Quercus rubra (L.) FACU- 6 Ranunculus abortivus (L.) FACW- 1 Ranunculus hispidus (Michx.) FAC 4 Rhus typhina (L.) UPL 2 Rorippa palustris ((L.) Besser) OBL 2 X X X Rorippa sylvestris ((L.)Besser) FACW * X X X Rosa multiflora (Thunb. ex Murray) FACU * X X X Rosa OBL 5 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 151 X X palustris (Marshall) Rosa setigera (Michx.) FACU Rosa sp. 4 na X X X X X X X Rubus allegheniensi s (Porter) FACU- 1 Rubus occidentalis (L.) UPL 1 Rudbeckia hirta (L.) FACU- 1 X Rudbeckia triloba (L.) FACU 5 X X X Rumex crispus (L.) FACU * Sagittaria latifolia (Willd.) OBL 1 X X X X X X Sagittaria sp. OBL * X X X Salix alba (L.) FACW * X X X X X Salix amygdaloides (Andersson) FACW 3 X X X X X Salix babylonica (L.) FACW- * X X X X X Salix interior (Rowlee) OBL 1 X X X X X X X X X X X X X X X X X X X X X X X X X X Salix matsudana Salix nigra (Marshall) FACW+ Salix sp. 2 X X X X X X X X X na X Sambucus canadensis OBL 3 X X X Samolus floribundus (Kunth) OBL 4 X X X Saururus cernuus (L.) OBL 8 X X X 152 X X X X X X X X X X X X X X Schoenoplect us acutus ((Muhl. ex Bigelow) Love & Love) OBL 7 OBL 2 X X X Scirpus atrovirens (Willd.) OBL 1 X X X Scirpus cyperinus ((L.) Kunth.) FACW+ 1 X X X X Scirpus fluviatilis ((Torr.) A. Gray) OBL 5 X X X X Scirpus pungens (Vahl) FACW+ 5 Seteria glauca ((L.) P. Beauv.) FAC * Setaria viridis ((L.) P. Beauv.) UPL * Sium suave (Walter) OBL 6 Solanum carolinense (L.) UPL * Solanum dulcamara (L.) FAC- * Solidago altissima (L.) FACU 1 Solidago graminifolia ((L.) Salisb.) FAC 1 Solidago juncea (Aiton) UPL 2 Solidago patula (Muhl. ex Willd.) OBL 6 Schoenoplect us tabernaemont ani ((C.C. Gmel.) Palla) X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 153 X X X X X X X X X X X X X X Solidago rugosa (Mill.) FAC Solidago sp. 2 X 8 X X Solidago speciosa (Nutt.) UPL 5 Solidago uliginosa (Nutt.) OBL 9 Sonchus oleraceus (L.) UPL * Sorghasrum nutans ((L.) Nash) UPL 5 Sparganium americanum (Nutt.) OBL 6 Sparganium eurycarpum (Engelm. ex A. Gray) OBL 4 Spartina pectinata (Link) OBL 5 Symplocarpu s foetidus ((L.) Salisb. ex Barton) OBL 7 Taraxacum officinale (Weber ex F.H. Wigg.) FACU- * Toxicodendro n radicans ((L.) Kuntze) FAC 1 Trifolium dubium (Sibth.) UPL Trifolium hybridum (L.) X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X * X X X FACU- * X X X X X Trifolium pratense (L.) FACU- * X X X Typha angustifolia (L.) OBL * X X X Typha latifolia (L.) OBL 1 X X X X X X X X X 154 Typha x glauca (Godr.) OBL * Typha sp. OBL na X X X Ulmus americana (L.) FACW- 2 X X X Ulmus rubra (Muhl.) FAC 3 X X Ulmus sp. X X X X X X X X X X X X X X X na Utrica dioica ((Muhl. ex Willd.) Wedd.) FAC- 1 Utricularia vulgaris (L.) OBL 6 Verbascum blattaria (L.) UPL * Verbascum thapsus (L.) UPL * X Verbena hastata (L.) FACW+ 4 X Verbena urticifolia (L.) FACU 3 Vernonia gigentea ((Walter) Trel.) FAC 2 X Vernonia noveboracens is ((L.) Michx.) FACW+ 3 X Vernonia sp. X X X OBL 6 Viburnum lentago (L.) FAC 5 Vicia sp. X X X X X X X X X X X X X na Vinca minor (L.) UPL * Viola sororia (Willd.) FAC- 1 X X X X X X X X X X X na Veronic scutellata (L.) X X X 155 Viola sp. na X Vitus riparia (Michx.) FACW 3 Vitis vulpina (L.) FAC 3 Xanthium strumarium (L.) FAC * X Species Wetland Indicator Status C of C Trumbull Creek Phase I X X 2008 2009 X 2010 X X X X X X Trumbull Creek Phase II North 2008 2009 2010 X X X X X X X X X X Trumbull Creek Phase II South 2008 2009 2010 Calamus Swamp 2010 Abies balsamea Abutilon theophrasti (Medik.) UPL * Acalypha rhomboidea (Raf.) FAC- 0 Acalypha virginica (L.) FACU- 0 Acer negundo (L.) FAC+ 3 Acer rubrum (L.) FAC 2 Acer saccharinum (L.) FAC 3 Acer saccharum (Marshall) FACU- 5 X n a X Acer sp. Acorus calamus (L.) OBL * Actaea alba (L.) UPL 7 Agrostis FACU- * X X X X X X X X X X 156 X X X X X X X X tenuis (Sibth.) Alisma plantagoaquatica (L.) OBL 2 Alliaria petiolata FACU * Allium canadense (L.) FACU 2 Ambrosia artemisiifolia (L.) FACU 0 Ambrosia trifida (L.) FAC 0 Andropogon gerardii (Vitman) FAC 5 Apocynum cannabinum (L.) FACU 1 Aristolochia serpentaria (L.) UPL 7 Artemisia vulgaris (L.) FACU- * Asclepias incarnate (L.) OBL 4 X X X Asclepias syriaca (L.) FACU- 1 X X X Asclepias tuberosa (L.) UPL 4 Asimina triloba ((L.) Dunal) FACU+ 6 Aster ericoides (L.) FACU 2 Aster lanceolatus (Willd.) FACW 3 Aster novaeangliae (L.) FACW- 2 X X Aster pilosus (Willd.) UPL 1 X X Aster FACW 6 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 157 X X X X X praealtus (Poir.) Aster racemosus (Elliott) FACW X X X n a Aster sp. Aster umbellatus (Mill.) 2 FACW Betula sp. 3 X n a X Bidens aristota ((Michx.)Brit ton) FACW- 4 Bidens cernua (L.) OBL 2 Bidens connata (Muhl. ex Willd.) FACW+ 3 Bidens coronata ((L.) Britton) OBL 3 Bidens frondosa (L.) FACW 2 X X X X X X X X X X X n a Bidens sp. X X Bidens vulgata (Greene) FACW 2 X Boehmeria cylindrica ((L.) Sw.) FACW+ 4 X Brasenia schreberi (J.F. Gmel.) OBL 7 Campsis radicans (L.) FAC 1 Carex bromoides (Schkuhr ex Willd.) FACW 7 X Carex frankii (Kunth) OBL 2 X X X X X X 158 X X X X X Carex intumescens (Rudge) FACW+ 5 X X X Carex lupilina (Muhl. ex Willd.) OBL 3 X X X Carex lurida (Wahlenb.) 0BL 3 X X X Carex tribuloides (Wahlenb.) FACW+ 4 X X X Carex sp. na Carex utriculata (Boott) OBL 7 Carex vulpinoidae (Michx.) OBL 1 X X Carpinus caroliniana (Walter) FAC 5 X X Carya glabra ((Mill.) Sweet) FACU- 5 X X Carya ovalis ((Wangenh.) Sarg.) UPL 5 X X Carya ovata ((Miller) K.Koch) FACU- 6 X Cassia fasiculata (Michx.) FACU 3 Catalpa bignoniodes (Walter) UPL * Cepthalanthu s occidentalis (L.) OBL 6 Chrisanthem um leucanthemu m (L.) UPL * Cichorium intybus (L.) UPL * Cicuta OBL 3 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 159 bulbifera (L.) Cicuta maculata (L.) OBL 3 Cicuta sp. OBL n a Cirscium altissimum ((L.) Hill) UPL 4 Cirscium arvense ((L.) Scop.) FACU * Convolvulus sepium (L.) FAC- 1 Cornus amomum (Mill.) FACW 2 Cornus florida (L.) FACU- 5 X X X X X X X X X X X X X X X X Cuscuta gronovii (Willd. Ex Schulte) FACW+ 3 Cuscuta sp. NA n a Cyperus erythrorhizos (Muhl.) FACW+ 4 Cyperus esculentus (L.) FACW 0 Cyperus squarrosus (L.) FACW+ 3 Cyperus strigosus (L.) FACW 1 X X X X X X X X X Daucus carota (L.) UPL * X X X X X X X X X Decodon verticillutus ((L.)Elliott) OBL 6 UPL 4 Desmodium cuspidatum ((Muhl. ex Willd.) DC ex X X n a Cornus sp. X X X X X X X X X X X X X X X X X X 160 Loudon) Dianthus armeria (L.) UPL * Dipsacus sylvestris (L.) FACU- * Duchesnea indica ((Andrews) Focke) FACU- * Echinacea purpurea ((L.) Moench) UPL 6 Echinochloa crusgali ((L.) P. Beauv.) FACU * X X Echinochloa muricata ((P. Beauv.) Fernald) FACW+ 3 X X Eleocharis acicularis ((L.) Roem. & Schult.) OBL 3 Eleocharis obtusa ((Willd.) Schult.) OBL 1 Eleocharis ovata ((Roth) Roem. & Schult.) OBL 9 Eleocharis quadrangulat a ((Michx.) Roem. & Schult.) OBL 4 Elodia canadensis (Michx.) OBL 3 Epilobium coloratum (Biehler) OBL 1 Epilobium sp. n a Equisetum sp. n a Erechtites FACU X X X X X X X X X X X X X X X X X X X X X X X X X X X 2 161 X X X X X X X X X X X X X X X hieracifolia ((L.) Raf. ex DC.) Erigeron annuus ((L.) Pers.) FACU 0 X X X X X X X X X n a Erigeron sp. Eupatorium fistulosum (Barratt) FACW 6 Eupatorium hyssopifolium (L.) UPL 4 Eupatorium maculatum (L.) FACW 6 Eupatorium perfoliatum (L.) FACW+ 3 Eupatorium serotinum (Michx.) FAC- 2 Festuca pratensis (Huds.) FACU- * Fragaria virginiana (Duchesne) FACU 1 Fraxinus americanus (L.) FACU 6 X Fraxinus pennsylvanic a (Marshall) FACW 3 X X X X X X X X X X X X X X X X X X X X X X X X X X n a Galium sp. Galium asperllum (Michx.) OBL 4 Galium tinctorium ((L.) Scop.) OBL 4 Geum aleppicum (Jacq.) FAC 3 Geum FAC+ 2 X 162 laciniatum (Murray) Geum lanceolatum (Murray) FAC+ 5 X N a Geum sp. Glechoma hederacea (L.) FACU * Gleditsia triacanthos (L.) FAC- 4 Glyceria striata ((Lam.) Hitchc.) OBL 2 Helenium autumnale (L.) FACW+ 4 Helianthus divaricatus (L.) UPL 4 Helianthus gigenteus (L.) FACW 6 Hemerocallis fulva ((L.)L.) UPL * Hibiscus laevis (All.) OBL 7 Hordem jubatum (L.) FAC 5 Hypericum canadense (L.) FACW 7 X X X Hypericum mutilum (L.) FACW 3 X X Hypericum perforatum (L.) UPL * Impatiens capensis (Meerb.) FACW 2 Ipomoea puppurea ((L.) Roth) UPL * Iris sp. X X X X X X X X X X X X X X X X X X X X X X X X X X X X n X X X 163 a Juglans nigra (L.) FACU 5 Juncus canadensis (J. Gay ex Laharpe) OBL 4 Juncus dudleyi (Wiegand) FACW- 3 Juncus effuses (L.) FACW+ 1 Juncus tenuis (Willd.) FAC- 1 Juncus torreyi (Coville) FACW 3 Lathyrus palustris (L.) FACU- 5 Leersia oryzoides ((L.) Sw.) OBL 1 X X X Lemna minor (L.) OBL 3 X X X Lespedeza violacea ((L.) Pers.) UPL 4 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X n a Lillium sp. Lindernia dubia ((L.) Pennell) OBL 2 Lobelia cardinalis (L.) FACW+ 5 Lobelia siphilitica (L.) FACW+ 3 Lonicera maackii ((Rupr.) Maxim.) UPL * X X X X X n a Lonicera sp. Lotus corniculatus X FACU- * X X X 164 (L.) Ludwigia alternifolia (L.) FACW+ 3 X X X Ludwigia palustris ((L.) Elliott) OBL 3 X X X Lycopus americanus (Muhl. ex W.P.C. Barton) OBL 3 X X X X X X n a Lycopus sp. Lycopus uniflorus (Michx.) OBL 3 Lysimachia nummularia (L.) OBL * Lythrum salicaria (L.) FACW+ * Mentha aravensis (L.) FACW 2 Mimulus ringens (L.) OBL 4 X X X Morus rubra (L.) FACU 7 X X X Nelumbo lutea (Willd.) OBL 7 Nuphar advena ((Aiton) W.T.Aiton) OBL 4 X X X Nymphaea odorata (Aiton) OBL 6 X X X Oenthera biennis (L.) FACU- 1 Onoclea sensibilis (L.) FACW 2 X n a X Oxalis sp. Oxalis acetosella (L.) X FAC- X X X X X X X X X X X X X X X X X X X X X X X X 9 165 X X Oxalis stricta (L.) UPL 0 Panicum dichotomiflor um (Michx.) FACW- 0 Panicum virgatum (L.) FAC 4 Parthenociss us quinquefolia ((L.) Planch.) FACU 2 Penthorum sedoides (L.) OBL 2 Phalaris arundinacea (L.) FACW+ * Phaseolus polystachios ((L.) B.S.P.) UPL 3 Phleum pretense (L.) FACU * Phragmites australis ((Cav.) Trin.) FACW * Phyla lanceolata ((Michx.)Gre ene) OBL 3 Phytolacca americana (L.) FACU+ 1 X Plantago major (L.) FACU * X Platanus occidentalis (L.) FACW- 7 Poa palustris (L.) FACW 5 Podophyllum peltatum (L.) FACU 4 Polygonum hydropiper (L.) OBL 1 Polygonum OBL 6 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Polygonum coccineum X X X X X X X 166 X X X X X X X hydropiperoi des (Michx.) Polygonum lapathifolia (L.) FACW+ 1 Polygonum pennylvanica (L.) FACW 0 Polygonum persicaria (L.) FACW * X X Polygonum sagittatum (L.) OBL 2 X X Polygonum virginianum (L.) FAC 3 Pontideria cordata (L.) OBL 6 Populus deltoides (W. Bartram ex Marshall) FAC 3 Populus tremuloides (Michx.) FACU 2 Potamogeton natans (L.) OBL 8 Potamogeton pectinatus (L.) OBL 2 Potamogeton sp. X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X n a Prenanthes altisima (L.) FACU- 4 X X X Prunella vulgaris (L.) FACU+ 0 X X X Quercus bicolor (Willd.) FACW+ 7 X X X X X Quercus palustris (Muenchh.) FACW 5 X X X X X Quercus rubra (L.) FACU- 6 X Ranunculus FACW- 1 X X X 167 X X X X X abortivus (L.) Ranunculus hispidus (Michx.) FAC 4 Rhus typhina (L.) UPL 2 Rorippa palustris ((L.) Besser) OBL 2 Rorippa sylvestris ((L.)Besser) FACW * Rosa multiflora (Thunb. ex Murray) FACU * X X X X X X Rosa palustris (Marshall) OBL 5 X X X X X X Rosa setigera (Michx.) FACU 4 X X n a Rosa sp. Rubus allegheniensi s (Porter) FACU- 1 Rubus occidentalis (L.) UPL 1 Rudbeckia hirta (L.) FACU- 1 Rudbeckia triloba (L.) FACU 5 Rumex crispus (L.) FACU * Sagittaria latifolia (Willd.) OBL 1 Sagittaria sp. OBL * Salix alba (L.) FACW * Salix amygdaloides (Andersson) FACW 3 X X X X X X X X X X X X X X X X X 168 Salix babylonica (L.) FACW- * Salix interior (Rowlee) OBL 1 FACW+ 2 Salix matsudana Salix nigra (Marshall) X X X n a Salix sp. Sambucus canadensis OBL 3 Samolus floribundus (Kunth) OBL 4 Saururus cernuus (L.) OBL 8 Schoenoplect us acutus ((Muhl. ex Bigelow) Love & Love) OBL 7 Schoenoplect us tabernaemont ani ((C.C. Gmel.) Palla) OBL 2 Scirpus atrovirens (Willd.) OBL 1 Scirpus cyperinus ((L.) Kunth.) FACW+ 1 Scirpus fluviatilis ((Torr.) A. Gray) OBL 5 Scirpus pungens (Vahl) FACW+ 5 Seteria glauca ((L.) P. Beauv.) FAC * Setaria viridis ((L.) P. Beauv.) UPL * X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 169 X Sium suave (Walter) OBL 6 Solanum carolinense (L.) UPL * Solanum dulcamara (L.) FAC- * Solidago altissima (L.) FACU 1 Solidago graminifolia ((L.) Salisb.) FAC 1 X X X Solidago juncea (Aiton) UPL 2 X X X Solidago patula (Muhl. ex Willd.) OBL 6 X X Solidago rugosa (Mill.) FAC 2 Solidago sp. X X X X 8 Solidago speciosa (Nutt.) UPL 5 Solidago uliginosa (Nutt.) OBL 9 Sonchus oleraceus (L.) UPL * Sorghasrum nutans ((L.) Nash) UPL 5 Sparganium americanum (Nutt.) OBL 6 Sparganium eurycarpum (Engelm. ex A. Gray) OBL 4 Spartina pectinata (Link) OBL 5 Symplocarpu s foetidus ((L.) Salisb. ex Barton) OBL 7 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 170 Taraxacum officinale (Weber ex F.H. Wigg.) FACU- * Toxicodendro n radicans ((L.) Kuntze) FAC 1 Trifolium dubium (Sibth.) UPL * Trifolium hybridum (L.) FACU- * Trifolium pratense (L.) FACU- * Typha angustifolia (L.) OBL * Typha latifolia (L.) OBL 1 Typha x glauca (Godr.) OBL * Typha sp. OBL n a Ulmus americana (L.) FACW- 2 X Ulmus rubra (Muhl.) FAC 3 X n a Ulmus sp. Utrica dioica ((Muhl. ex Willd.) Wedd.) FAC- 1 Utricularia vulgaris (L.) OBL 6 Verbascum blattaria (L.) UPL * Verbascum thapsus (L.) UPL * Verbena hastata (L.) FACW+ 4 Verbena urticifolia (L.) FACU 3 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 171 X X X X Vernonia gigentea ((Walter) Trel.) FAC 2 Vernonia noveboracens is ((L.) Michx.) FACW+ 3 X X X X X X X X n a Vernonia sp. Veronic scutellata (L.) OBL 6 Viburnum lentago (L.) FAC 5 n a Vicia sp. Vinca minor (L.) UPL * Viola sororia (Willd.) FAC- 1 X X X X X X X X n a Viola sp. Vitus riparia (Michx.) FACW 3 Vitis vulpina (L.) FAC 3 Xanthium strumarium (L.) FAC * 172 Appendix D: Olentangy River Wetland Research Park Experimental Wetlands Vegetation Community Maps from 2008-2011 173 Figure D.1 2008 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park 174 Figure D.2 2009 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park 175 Figure D.3 2010 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park 176 Figure D.4 2011 vegetation map of dominant communities in the two experimental wetlands at the Olentangy River Wetland Research Park 177 Appendix E: Calculations for Metabolism Chambers Gross Primary Productivity and Respiration gC = m2 hr ( Flow Rate * ) ∆ mg C-CO2 m3 * 60 *60 Area of Chamber Base * 1000 ∆ mg C-CO2 m3 = ( 12.01 * ppmin CO2 * atm 0.08214 * Kin - 12.01 * ppmout CO2 * atm 0.08214 * Kout ) ppmin = ppm CO2 from Inflow ppmout = ppm CO2 from Outflow atm = Barometric Pressure (atm) Kin = Ambient Temperature (K) Kout = Chamber Temperature (K) Flow Rate (m3/s) = (√ 2*lb/ft2 ρ ) * 1.12 * CA * 0.02832 lb/ft2 = Air Pressure Reading from Inflow Pitot Tube CA = Cross Sectional Area of Pipe ρ (slug/ft ) = 3 lb/ft2 1716.0 * R lb/ft2 = Barometric Pressure R = Ambient Temperature (R) 178 Appendix F: Statistical Tables 179 F.1 Chapter 2 Statistical Tables F.1.1 Mitigation vs. Reference Wetlands aov1<-aov(Species.Richness~status) summary(aov1) Df status Residuals Mean F value Pr(>F) Sq 7363 7363 20.33 7e-05 12675 362 Sum Sq 1 35 *** aov1<-aov(NumberCommunities~status) summary(aov1) Df status Residuals Mean F value Pr(>F) Sq 1 9.95 9.946 1.548 0.254 35 258.32 7.381 Sum Sq aov5<-aov(FQAIscore~status) summary(aov5) Df status Residuals Mean F value Pr(>F) Sq 63.7 63.73 4.451 0.0421 * 501.2 14.32 Sum Sq 1 35 ANOV3<-lm(H~status) summary.aov(ANOV3) Mean F value Pr(>F) Sq 1 0.2917 0.29168 1.6309 0.2117 29 5.1865 0.17884 6 observations deleted due to missingness Df status Residuals Sum Sq ANOV4<-lm(CDI~status) summary.aov(ANOV4) Df status Residuals Mean F value Pr(>F) Sq 1 0.2859 0.28587 2.014 0.1647 35 4.9681 0.14195 Sum Sq aov8<aov(Biomass.Weighted.by.Community.area~status) summary(aov8) Df status Residuals 180 Mean F value Pr(>F) Sq 1 427293 427293 18.63 0.000124 *** 35 802670 22933 Sum Sq aov1<-aov(loganpp~status) summary(aov1) Df status Residuals 1 35 181 Mean F value Pr(>F) Sq 0.764 0.764 6.864 0.0129 * 3.896 0.1113 Sum Sq F.1.2 Age of Mitigation Bank Wetlands aov4<-aov(Species.Richness~ATS) summary(aov4) Df ATS Residuals 1 28 Sum Sq Mean Sq F value Pr(>F) 1887 1887.1 5.031 0.033 * 10502 375.1 1 28 Sum Sq Mean Sq F value Pr(>F) 1.22 1.217 0.131 0.72 260.73 9.312 1 28 Sum Sq Mean Sq F value Pr(>F) 116.7 116.69 9.218 0.00513 ** 354.6 12.66 1 28 Sum Sq Mean Sq F value Pr(>F) 0.247 0.24706 1.653 0.209 4.185 0.14946 aov3<-aov(NumberCommunities~ATS) summary(aov3) Df ATS Residuals aov5<-aov(FQAIscore~ATS) summary(aov5) Df ATS Residuals aov2<-aov(H.~ATS) summary(aov2) Df ATS Residuals aov1<-aov(CDI~ATS) summary(aov1) Df ATS Residuals 1 28 Sum Sq Mean Sq F value Pr(>F) 0.268 0.2682 1.827 0.187 4.111 0.1468 Df Sum aov6<aov(Biomass.Weighted.by.Community.area~ATS) summary(aov6) Df ATS Residuals 1 28 Sum Sq Mean Sq F value Pr(>F) 20612 20612 8.705 0.006 ** 66299 2368 1 28 Sum Sq Mean Sq F value Pr(>F) 0.1321 0.13209 14.374 0.000787 *** 0.2573 0.00919 aov7<-aov(loganppw~ATS) summary(aov7) Df ATS Residuals 182 F.1.3 Hydrology aov2<-aov(Species.Richness~Hydrology) summary(aov2) Df Hydrology Residuals Sum F Mean Sq Pr(>F) Sq value 2 9751 4875 16.11 1.2e-05 34 10288 303 *** aov2<-aov(NumberCommunities~Hydrology) summary(aov2) Df Hydrology Residuals Sum F Mean Sq Pr(>F) Sq value 2 14.93 7.466 1.025 0.367 34 247.66 7.284 aov6<-aov(FQAIscore~Hydrology) summary(aov6) Df Hydrology Residuals Sum F Mean Sq Pr(>F) Sq value 2 116.1 58.06 4.399 0.02 * 34 448.8 13.2 ANOV9<-lm(H~Hydrology) summary.aov(ANOV9) Df Hydrology Residuals Sum Sq Mean Sq F Pr(>F) value 0.01302 0.0691 0.7945 1 0.18845 29 5.4651 3 6 observations deleted due to missingness 1 0.013 ANOV10<-lm(CDI~Hydrology) summary.aov(ANOV10) Df Hydrology Residuals Sum F Mean Sq Pr(>F) Sq value 2 0.4617 0.23086 1.6379 0.2093 34 4.7923 0.14095 aov9<-aov(Biomass.Weighted.by.Community.area~Hy drology) summary(aov9) Df Hydrology Residuals 183 Sum F Mean Sq Pr(>F) Sq value 2 236863 118431 4.055 0.0263 * 34 993100 29209 F.1.4 Location in Ohio aov3<-aov(Species.Richness~Location) summary(aov3) Df Location Residuals Mean F Pr(>F) Sq value 3400 3400 7.151 0.0113 * 16639 475 Sum Sq 1 35 aov4<-aov(NumberCommunities~Location) summary(aov4) Df Location Residuals Mean F Pr(>F) Sq value 121.6 121.64 29.04 4.94e-06 146.6 4.19 Sum Sq 1 35 *** aov7<-aov(FQAIscore~Location) summary(aov7) Df Location Residuals ANOV5<-lm(H~Location) summary.aov(ANOV5) Sum Sq Location Residuals Mean F Pr(>F) Sq value 163.7 163.7 14.28 0.000589 *** 401.2 11.46 Sum Sq 1 35 Mean Sq F value Pr(>F) 1 0.1294 0.12938 0.7015 0.4091 29 5.3488 0.18444 6 observations deleted due to missingness > > ANOV6<-lm(CDI~Location) summary.aov(ANOV6) Df Location Residuals Mean F Pr(>F) Sq value 0.7625 0.76252 5.942 0.02 * 4.4915 0.12833 Sum Sq 1 35 aov3<aov(Biomass.Weighted.by.Community.area~Location) summary(aov3) Df Location Residuals 184 Mean F Pr(>F) Sq value 1 3023 3023 0.087 0.77 35 1223272 34951 Sum Sq F.2 Chapter 3 Statistical Tables F.2.1 Wetland vegetation aov6<-aov(Species.Richness~Wet land*YS) summary(aov6) Df Wetland YS Wetland:YS Residuals Sum Sq 1 1 1 2 37.5 6.25 0.25 1.5 Mean Sq F value Pr(>F) 37.5 50 0.0194 * 6.25 8.333 0.102 0.25 0.333 0.622 0.75 aov4<-aov(FQAIscore~Wetland*YS) summary(aov4) Df Wetland YS Wetland:YS Residuals Sum Sq Mean Sq F value Pr(>F) 1 18.027 18.027 540.8 0.00184 ** 1 0.09 0.09 2.7 0.24206 1 0.09 0.09 2.7 0.24206 2 0.067 0.033 aov3<-aov(CDI~Wetland*YS) summary(aov3) Df Wetland YS Wetland:YS Residuals 1 1 1 2 Sum Sq Mean Sq F value Pr(>F) 0.05607 0.05607 0.624 0.512 0.06003 0.06003 0.668 0.5 0.00023 0.00023 0.003 0.965 0.17962 0.08981 1 1 1 2 Sum Sq Mean Sq F value Pr(>F) 20.17 20.167 2.847 0.234 12.25 12.25 1.729 0.319 0.25 0.25 0.035 0.868 14.17 7.083 1 1 1 2 Sum Sq Mean Sq F value Pr(>F) 24890 24890 158.26 0.00626 ** 242 242 1.54 0.34047 2992 2992 19.02 0.04875 * 315 157 aov11<aov(macrophyte~Wetland*YS) summary(aov11) Df Wetland YS Wetland:YS Residuals aov7<aov(WANPPannual~Wetland*YS) summary(aov7) Df Wetland YS Wetland:YS Residuals 185 aov8<aov(WBNPPannual~Wetland*YS) summary(aov8) Df Wetland YS Wetland:YS Residuals 1 1 1 2 Sum Sq Mean Sq F value Pr(>F) 42447 42447 2.832 0.234 68826 68826 4.592 0.165 5618 5618 0.375 0.603 29977 14988 1 1 1 2 Sum Sq Mean Sq F value Pr(>F) 132346 132346 7.355 0.113 60903 60903 3.385 0.207 16810 16810 0.934 0.436 35987 17993 aov10<aov(tnpp.annual~Wetland*YS) summary(aov10) Df Wetland YS Wetland:YS Residuals 186 F.2.2 Nutrient Analysis aov1<-aov(logn~Wet land) summary(aov1) Df Wetland Residuals 1 77 Sum Sq Mean Sq F value Pr(>F) 0.0093 0.009324 0.59 0.445 1.2162 0.015795 aov2<-aov(logp~Wet land) summary(aov2) Df Wetland Residuals Sum Sq 1 77 0 3.638 Mean Sq F value Pr(>F) 0.00017 0.004 0.953 0.04725 0.442 3.527 Mean Sq F value Pr(>F) 0.4421 9.652 0.00265 ** 0.0458 aov3<-aov(logk~Wet land) summary(aov3) Df Wetland Residuals Sum Sq 1 77 aov4<-aov(Ca~Wet land) summary(aov4) Df Wetland Residuals aov6<-aov(srtal~Wet land) > Wetland Residuals Sum Sq 1 8.279e+07 77 1.606e+09 Mean Sq F value Pr(>F) 82791300 3.969 0.0499 * 20862048 summary(aov6) Df Sum Sq Mean Sq F value Pr(>F) 1 1.407 1.4066 7.642 0.00713 ** 77 14.172 0.1841 aov9<-aov(logfe~Wet land) summary(aov9) Df Wetland Residuals Sum Sq 1 77 0.58 9.711 Mean Sq F value Pr(>F) 0.5804 4.603 0.0351 * 0.1261 187 aov10<-aov(Mn~Wet land) summary(aov10) Df Sum Sq Wetland Residuals 1 77 Mean Sq 167 413500 167 5370 F value Pr(>F) 0.031 0.861 aov<aov(N~year) summary(aov) Df Sum Sq year Residuals 1 2 Mean Sq 3.585 0.995 F value 3.585 0.497 Pr(>F) 7.209 0.115 aov3<-aov(logk~Spe cies) summary(aov3) Df Species Residuals Sum Sq 8 70 2.529 1.44 Mean Sq F value Pr(>F) 0.31613 15.37 8.89e-13 0.02057 *** Mean Sq F value Pr(>F) 166229979 32.38 <2e-16 5133274 *** aov17<-aov(Ca~Spe cies) summary(aov17) Df Species Residuals Sum Sq 8 1.330e+09 70 3.593e+08 aov6<-aov(srtal~Spe cies) summary(aov6) Df Species Residuals Sum Sq 8 70 4.646 10.933 Mean Sq F value Pr(>F) 0.5808 3.719 0.00113 ** 0.1562 aov9<-aov(logfe~Spe cies) summary(aov9) Df Species Residuals Sum Sq 8 70 2.958 7.333 Mean Sq F value Pr(>F) 0.3697 3.529 0.00175 ** 0.1048 188 F.2.3 Edge Vegetation aov1<aov(hanpp~Wetland+YS) summary(aov1) Df Sum Sq Wetland YS Residuals 1 1 1 Mean Sq 529 9 225 F value 529 9 225 Pr(>F) 2.351 0.04 0.368 0.874 aov2<aov(hbnpp~Wetland+YS) summary(aov2) Df Wetland YS Residuals 1 1 1 Sum Sq Mean Sq F value 3861225 3861225 3218436 3218436 357604 357604 Pr(>F) 10.8 9 0.188 0.205 total litterfall aov1<-aov(talf~wetland) summary(aov1) Df Sum Sq wetland Residuals 1 34 55 58540 Mean Sq 54.6 1721.8 F value Pr(>F) 0.032 0.86 tree aboveground net primary pro ductivity aov<-aov(tnpp~wetland) summary(aov) Df wetland Residuals 1 4 Sum Sq Mean Sq F value Pr(>F) 0.0236 0.02359 0.177 0.696 0.5341 0.13353 aov<aov(sd~w) summary(aov) Df w Residuals Sum Sq 1 22 1.17 1.61 Mean Sq F value Pr(>F) 1.1702 15.99 0.000605 *** 0.0732 189 F.3 Chapter 4 Statistical Tables F.3.1 Gross Primary Productivity aov1<-aov(gpp~year) summary(aov1) Df year Residuals Sum Sq Mean Sq F-value 1 0 0 38 970 25.53 Pr(>F) 0 0.997 aov2<-aov(gpp~month) summary(aov2) Df month Residuals Sum Sq Mean Sq 5 468.9 93.78 34 501.1 14.74 F-value 6.364 Pr(>F) 0.000286 *** aov3<-aov(gpp~species) summary(aov3) Df species Residuals Sum Sq Mean Sq 4 351.2 87.79 35 618.8 17.68 F-value 4.965 Pr(>F) 0.00281 ** aov1<-aov(gpp~solar) summary(aov1) Df solar Residuals Sum Sq Mean Sq 1 283.7 283.66 38 686.4 18.06 F value 15.71 Pr(>F) 0.000315 *** aov1<-aov(gpp~ambient) summary(aov1) Df ambient Sum Sq 1 227 Mean Sq 227.05 190 F value 11.69 Pr(>F) 0.00173 ** Residuals 32 621.7 19.43 aov4<-aov(gpp~soil) summary(aov4) Df soil Residuals Sum Sq Mean Sq F value 1 245.5 245.51 32 603.2 18.85 Pr(>F) 13.02 0.00104 ** aov2<-aov(gpp~wd) summary(aov2) Df wd Residuals Sum Sq Mean Sq F value 1 18.2 18.21 32 830.5 25.95 Pr(>F) 0.702 0.408 Tukey multiple comparisons of means 95% family-wise confidence level Fit: aov(formula = gpp ~ species) $species diff lwr upr p adj pharg-open 7.39705627 1.26151561 13.5325969 0.0115694 scirpus-open 1.54089259 -4.83071609 7.9125013 0.9561739 sparg-open 1.5239843 -6.27961075 9.3275794 0.9797372 typha-open 6.22748877 -0.01538727 12.4703648 0.0508264 scirpus-pharg -5.85616368 -11.28988982 -0.4224375 0.0293667 sparg-pharg -5.87307196 -12.93168927 1.1855453 0.1413911 typha-pharg -1.1695675 -6.45175302 4.112618 0.9679899 sparg-scirpus -0.01690829 -7.28165992 7.2478433 1 typha-scirpus 4.68659618 -0.86804349 10.2412358 0.1322577 typha-sparg 4.70350447 -2.44860854 11.8556175 0.3409683 191 Tukey multiple comparisons of means 95% family-wise confidence level Fit: aov(formula = gpp ~ month) $month diff August-April lwr upr p adj 7.4694196 0.3738395 14.5649998 0.0342913 July-April 10.1216729 3.0260928 17.2172531 0.0017244 June-April 9.3468142 1.8674161 16.8262124 0.007505 May-April 4.2136815 -2.8818987 11.3092616 0.483828 September-April 2.3586492 -5.120749 9.8380474 0.9296991 July-August 2.6522533 -3.1412636 8.4457702 0.7373203 June-August 1.8773946 -4.3803189 8.1351081 0.9424242 May-August -3.2557382 -9.0492551 2.5377787 0.5435877 September-August -5.1107704 -11.3684839 1.146943 0.1632857 June-July -0.7748587 -7.0325722 5.4828548 0.9989606 May-July -5.9079915 -11.7015084 -0.1144746 0.0434788 September-July -7.7630238 -14.0207372 -1.5053103 0.0080777 May-June -5.1331328 -11.3908463 1.1245807 0.1599124 September-June -6.988165 -13.6779421 -0.298388 0.0363672 September-May -1.8550323 -8.1127457 4.4026812 0.9451575 192 F.3.2 Respiration aov7<-aov(resp~year) summary(aov7) Df year Residuals Sum Sq 1 38 Mean Sq 5.7 459.9 F-value 5.717 12.102 Pr(>F) 0.472 0.496 aov8<-aov(resp~month) summary(aov8) Df month Residuals Sum Sq 5 34 Mean Sq 140.6 325 F-value 28.12 9.559 Pr(>F) 2.942 0.026 aov10<-aov(resp~spe cies) summary(aov10) Df species Residuals Sum Sq 4 35 Mean Sq 59.1 406.6 F-value 14.76 11.62 Pr(>F) 1.271 0.3 aov4<-aov(resp~solar) summary(aov4) Df solar Residuals Sum Sq 1 32 Mean Sq F value 14.36 14.359 307.63 9.613 Pr(>F) 1.494 0.231 aov6<-aov(resp~ambient) summary(aov6) Df ambient Residuals Sum Sq 1 32 Mean Sq 41.31 280.68 F value 41.31 8.77 Pr(>F) 4.71 0.0375 aov9<-aov(resp~soil) summary(aov9) Df soil Residuals Sum Sq 1 32 26.09 295.9 Mean Sq F value 26.088 9.247 Pr(>F) 2.821 0.103 aov7<-aov(resp~wd) summary(aov7) Df wd Residuals Sum Sq 1 32 Mean Sq 5.2 316.8 193 F value 5.159 9.901 Pr(>F) 0.521 0.476 Fit: Tukey multiple comparisons of means 95% family-wise confidence level aov(formula = resp ~ month) $month diff August-April July-April June-April May-April September-April July-August June-August May-August September-August June-July May-July September-July May-June September-June September-May lwr -0.5584066 -1.2301503 -0.2714699 3.3138235 3.1461692 -0.6717437 0.2869367 3.8722301 3.7045758 0.9586805 4.5439738 4.3763196 3.5852933 3.4176391 -0.1676542 upr -6.2728773 -6.944621 -6.2950509 -2.4006472 -2.8774118 -5.3375895 -4.7527527 -0.7936157 -1.3351136 -4.081009 -0.121872 -0.6633699 -1.4543961 -1.9700155 -5.2073437 194 5.156064 4.48432 5.752111 9.028294 9.16975 3.994102 5.326626 8.538076 8.744265 5.99837 9.20982 9.416009 8.624983 8.805294 4.872035 p adj 0.9996711 0.9861333 0.9999928 0.509777 0.618958 0.9978583 0.9999771 0.1511007 0.2558845 0.9920945 0.0599484 0.1196508 0.2884381 0.4110625 0.9999984 F.3.3 Methane Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by year chi-squared = 2.3775, df = 1, p-value = 0.1231 Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by month Chi-squared = 21.349, df = 5, p-value = 0.0006958 Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by species chi-squared = 3.5147, df = 3, p-value = 0.3189 df = 37, p-value = 0.181 df = 70, p-value = 0.4451 df = 34, P-value = 0.049 df = 28, p-value = 0.02272 Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by solar chi-squared = 44.657, Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by ambient chi-squared = 70.9715, Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by soil Chi-squared = 48.732, Kruskal-Wallis rank sum test data: Kruskal-Wallis ch4 by depth chi-squared = 44.8744, 195 p.value: Comparisons Multiple comparison test after Kruskal-Wallis 0.05 obs.dif April-August April-July April-June April-May April-September August-July August-June August-May August-September July-June July-May July-September June-May June-September May-September critical.dif difference 21.5625 32.47013FALSE 37.0625 32.47013TRUE 41.75 32.47013TRUE 22 32.47013FALSE 14.4375 32.47013FALSE 15.5 26.51175FALSE 20.1875 26.51175FALSE 0.4375 26.51175FALSE 7.125 26.51175FALSE 4.6875 26.51175FALSE 15.0625 26.51175FALSE 22.625 26.51175FALSE 19.75 26.51175FALSE 27.3125 26.51175TRUE 7.5625 26.51175FALSE Wilcoxon rank sum test with continuity correction data: ch4[month April] and ch4[month June] W = 5, p-value = 0.0003405 alternative hypothesis: true location shift is not equal to 0 95 percent confidence interval: -28.87594 sample estimates: -10.53378 difference in location Wilcoxon rank sum test with continuity correction data: ch4[month April] and ch4[month July] W = 16, p-value = 0.003629 alternative hypothesis: true location shift is not equal to 0 95 percent confidence interval: -30.159909 sample estimates: difference in location 196 -6.600953 Wilcoxon rank sum test with continuity correction data: ch4[month June] and ch4[month September] W = 213, p-value = 0.001449 alternative hypothesis: true location shift is not equal to 0 95 percent confidence interval: 6.108392 sample estimates: difference in location 197 21.978579
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