Modeling Wildlife Responses to a Proposed Marsh
Enhancement for the McDaniel Slough Project Area
Arcata, California
A report to:
The California Department of Fish and Game
and
The City of Arcata, Environmental Services
Prepared by:
Matthew Johnson and the Upland Wildlife Habitat Ecology Class
Spring 2002
Department of Wildlife
Humboldt State University
1 June, 2002
This report stems from work conducted by the Humboldt State University’s Upland
Wildlife Habitat Ecology class of spring 2002. Students participating in the project were
(in alphabetical order): Monet Belltawn, Julia Boland, Kelley Breen, Kevin Crouch,
Suzanna Elkjer, Bradley Eversull, Terrence Glab Jr, David Gonzales, Justin McMahon,
Petrena Muscio, Chet Ogan, Carrie Ransom, Lindsay Reynolds, Josh Schmalenberger,
Morgan Strachan, Travis Taylor, James Tietz, Jonathon Velasquez, Jesse Waite, and
Clarence Weckman. Efforts by Chet Ogan and James Tietz were especially helpful in
summarizing current vegetation and wildlife surveys, respectively. Their instructor, Matt
Johnson, compiled individually written reports by each student, finalized the modeling
process, and prepared this document.
We thank Dr. Stan Harris (HSU emeritus professor) and Andrea Pickart (USFWS) for
presenting to the class the merits of fresh and salt marsh considerations for the restoration
project. We thank the City of Arcata, especially Brian Kang, for thoughtful and patient
cooperation in providing GIS maps of the area, and we thank the Redwood Sciences Lab
(USFS) for its donation of computer and large-format printer time. The California
Department of Fish and Game provide permission to work in the area and was helpful
along the way. Drs. Rick Brown, Stan Harris, and Tim Lawlor of HSU offered
comments on the realism of model-predictions for mammals and birds; Dr. Hartwell
Welsh of the Redwood Sciences Lab provided comments for reptiles and amphibians.
Andrea Pickart kindly permitted the use of photographs and the salt marsh map on page
1. Carol Ralph and Juli Neander were helpful with assisting plant identification. The
Wildlife stockroom provided field equipment.
ii
Summary
1. The McDaniel Slough Project Area (MSPA) along the northern shore of Humboldt
Bay is a potential site for the reintroduction of salt marsh. Our objectives were to (a)
describe the current vegetation in the area, (b) predict potential vegetation according
to three alternative management scenarios that would breach levees and allow salt
water to inundate the area, (c) conduct and compare wildlife surveys of the MSPA
and a representative salt marsh, and (d) use the California Wildlife Habitat
Relationship system to model potential wildlife effects of each management scenario.
2. The MSPA is currently dominated by perennial grassland and pasture; small
riparian inclusions, levees dominated by coastal shrubs, and interspersed shrubs and
small trees add structural complexity (Fig. 2). This diversity of habitat results in
higher (non-fish vertebrate) wildlife species richness and diversity than in a
representative salt marsh nearby (Table 6, Fig. 9).
3. The most recently proposed management scenario (“Alternative 4”) involves a
narrow breach of the bay-side levee, which would constrain the passage of salt water
into and out of the MSPA, creating a “muted” tidal flow. This muted-flow scenario
would result in the creation of 37 ha of salt marsh, of which 6 ha would be of an
elevation favorable for locally rare salt marsh plants. However, because much of the
area inside the bay levee is low in elevation, this scenario would create approximately
50 ha of tidal mudflat habitat. The same scenario with a wider levee breach would
allow a relatively free passage of salt water into and out of the MSPA, creating a
“full” tidal flow that may restrict the resulting salt marsh to a higher elevation. This
full-flow scenario would thus result in only 11 ha of salt marsh and over 75 ha of
mudflat. A third scenario with a levee protecting 40 ha of the lowest elevation
perennial grassland from salt water inundation (the “Green & Gold” scenario) would
result in 29 ha of salt marsh (with 6 favorable for the rare plants) and only 15 ha
of mudflat. Figures 6-8 illustrate the vegetation predicted under each of these scenarios.
4. Modeling results suggest more species would be positively than negatively affected
by all three scenarios, though many positive responses stem from the creation of new
freshwater ponds and riparian woodlands and not the creation of salt marsh. The
iii
Green & Gold scenario offers the most positive wildlife responses, followed by the
Alternative 4-muted and then the Alternative-4 full flow scenarios (Fig. 10). Guilds
reliant on grassland habitats (e.g., rodents, raptors, insectivores, grassland songbirds)
would be especially negatively impacted by both the Alternative 4- muted and full
flow scenarios (Table 10). The Green & Gold scenario greatly mitigates these losses
by retaining some perennial grassland habitat at the expense of less mudflat, which is
little-used by wildlife. Shorebirds and, to a lesser extent, waterbirds respond
favorably to the creation of mudflat and thus would be less positively affected by the
Green & Gold scenario than either Alternative 4 scenario.
5. Although salt marsh supports low wildlife diversity, endemic plants of the MSPA
make more substantive contributions to gamma diversity than do virtually any of the
wildlife species. Therefore, the reintroduction of some salt marsh is therefore
advisable from a biodiversity perspective. However, mudflats are locally common
and offer relatively little from either a botanical or wildlife perspective, so our
recommendation is to optimize the project area by reintroducing some salt marsh
while restricting mudflat and retaining some perennial grassland.
6. Our modeling results should be interpreted with caution because the tidal elevational
threshold below which salt marsh will not become established profoundly influences
all predictions of a proposed breaching of levees along the bay. We suggest
additional data be obtained to better predict this threshold and understand the capacity
for MSPA’s soil to expand after inundation with salt water.
iv
Table of Contents
Summary ............................................................................................................................ iii
Introduction..........................................................................................................................1
Methods................................................................................................................................4
Current vegetation
Potential vegetation
Wildlife surveys
Wildlife-habitat-modeling
Results................................................................................................................................10
Current vegetation
Potential vegetation
Wildlife surveys
Wildlife-habitat-modeling
Discussion ..........................................................................................................................17
Literature Cited ..................................................................................................................21
Tables (1-10)......................................................................................................................24
Figures (1-10).....................................................................................................................34
Appendices (1-4)................................................................................................................44
v
Introduction
Over the past 130 years, 87% of the native salt marsh around Humboldt Bay has
been converted to agricultural wetlands, pasture, and city development (Williams et al.
1985). Less than 600 acres of salt marsh remain around the bay (A. Pickert, pers. com.,
see figure at right). This loss has had a profound effect on the bay’s ecology because
high productivity salt marshes are legendary for
providing valuable ecological services, such as
the delivery of nutrients to coastal habitats,
absorption of water pollution, and added
See close-up
view below
structural complexity required by many
immature estuarine fish and invertebrates (Long
and Mason 1983, Ricklefs 1990). The
conversion of Humboldt Bay’s salt marshes also
threatens several rare plant species, such as the
Humboldt Bay owl’s clover (Castilleja ambigua
spp. humboldtiensis) and the Point Reyes bird’s
beak (Cordylanthus maritimus spp. palustris).
The McDaniel Slough Project Area
Source: U.S. Fish & Wildlife Service National Wetland Inventory
(MSPA) along the northern shore of Humboldt Bay is a potential site for the
reintroduction of salt marsh. The
N
W
area is approximately 103 ha and
E
straddles the McDaniel Slough,
S
lo
McDaniel S
ug
Grassland
Pasture
also known as the lower reaches
of Janes Creek (see figure at
h
left). The California Department
of Fish and Game (CDFG)
purchased the area west of
200
0
200
400 Meters
McDaniel Slough in 1988 as part
of the Mad River Wildlife Area,
and insufficient management funds have allowed the area to go fallow with non-native
grasses. The City of Arcata acquired the Hunt property (pasture in figure) and several
1
other holdings east of the slough in 1999. The City’s acquisitions were intended to allow
the expansion of the Arcata Marsh and Wildlife Sanctuary and/or the spread of Janes
Creek floodwaters into low-lying areas to relieve flooding concerns (during the winters of
1996-97 and 1997-98 heavy rains coincided with peak high tides causing Janes Creek to
back up between 11th and 14th Streets). Currently, the CDFG and the City of Arcata are
jointly managing the area. They have proposed a salt marsh restoration effort, which
would involve breaching levees along the bay and allowing high tides to inundate the
area with salt water. Tidal action would then reintroduce salt marsh plants to the area
naturally. Thus, the area offers an important salt marsh restoration opportunity.
However, prior research and observations have shown that the MSPA houses
significant wildlife populations in its current grassland state (Dunk 1992, Harris 1996).
Tall perennial grasslands around Humboldt Bay
support abundant rodent populations, including
the highest densities of California voles ever
reported (Dunk 1992). Consequently, these
habitats provide important hunting grounds for
several raptors, especially the Northern Harrier,
the White-tailed Kite, and the Short-eared Owl
(scientific names for all wildlife species
mentioned in the text are provided in Appendix
1). Like salt marsh, the distribution of perennial
grasslands around Humboldt Bay has also
contracted from historic conditions, so the reversion of the MSPA from glassland to salt
marsh would negatively affect grassland species.
At a public meeting in May 2000, the City of Arcata prepared a list of objectives,
opportunities, and constraints associated with the project. Local ranchers, other
concerned community members, wildlife and botany professionals, and city staff
discussed proposals by a consulting firm, Philip Williams and Associates. Public
comments varied from those strongly supporting the plan (largely for botanical,
ichthyological, or recreational reasons) to those in strong opposition (largely for bird and
other wildlife reasons). In February 2001, another meeting was held in which similar
2
concerns were voiced, with some tension among opposing viewpoints. Dr. Stan Harris
(2001) in a letter to the Arcata Eye argued against the salt marsh plan and encouraged
considering an additional freshwater habitat in the project area by expanding the Arcata
Marsh & Wildlife Sanctuary. This was followed by a rebuttal from the local chapter of
the California Native Plant Society (CNPS 2001). A third public meeting was held in
November 2001, during which CDFG and the City of Arcata described their mostfavored option, called “Alternative 4,” which includes the creation of both fresh and salt
marsh habitats (see Fig. 1; figures are appended to the end of this report, beginning on page
34).
Fresh
and brackish ponds would be created near the current Arcata Marsh & Wildlife Sanctuary
(some to serve in municipal wastewater treatment), and breached levees along the bay
would permit tidal action to reintroduce salt marsh in the remainder of the area. David
Anderson, in an article in the Times Standard (8 Feb 2001) and a Times Standard
editorial (9 Feb 2001), summarized the marsh restoration plan and the various public
concerns.
In the spring of 2002, Humboldt State University’s Upland Wildlife Habitat
Ecology class undertook a course project to evaluate the wildlife responses to the
proposed restoration of the MSPA. We had four objectives. First, we sought to describe
the current vegetation of the area through plant surveys, Global Positioning System
(GPS) mapping of important shrub elements, and Geographic Information System (GIS)
analysis of broad vegetation types. Second, we sought to predict potential vegetation
likely to occur in the MSPA resulting from three different habitat management scenarios:
two variations of Alternative 4 and one scenario that would retain some of the existing
perennial grassland. Our third objective was to conduct and compare wildlife surveys of
the MSPA and a nearby salt marsh similar in extent to that likely to occur after breaching
the levees. Fourth, we sought to use the California Wildlife Habitats Relationship
computer modeling system (CWHR; Mayer and Laudenslayer 1988) to predict the
wildlife responses to each of the three habitat management scenarios.
3
Methods
Current Vegetation
We described current vegetation at the MSPA with vegetation transects, GPS
mapping of important shrub elements, and Geographic Information System (GIS)
analysis of broad vegetation types. East-west transects spanning the width of the
grassland, pasture, and freshwater sloughs were distributed systematically at 5 or 10 m
intervals, depending on region and date. Along each transect at 5 m intervals, surveyors
identified the plant at the tip of the right foot (as described in Higgins et al. 1996) to the
lowest possible taxon or morphological group. These data were analyzed to yield
estimates of frequency for various plant groups, which serve as indicators of basal cover.
We used several methods to help identify plants as accurately as possible. On 9
March Carol Ralph, a local member of California Native Plant Society, helped us identify
common plants in the area. Juli Neander on the City of Arcata staff provided us a copy
of a plant survey of the project area done by a consultant, Mignon Bivin, in fall 1998 and
spring 2000. In addition, the Arcata Marsh Interpretative Center provided a list of
common plants around the Arcata Marsh project and a photo album of common plants
around the Marsh Project. Nonetheless, plant identification was difficult because most
plant keys rely on flowers and mature vegetative structures for definitive identification,
and most plants were not in bloom in early March. Moreover, various students collected
the data with varying degrees of plant identification skill. Thus, our project-wide
analyses were constrained by the lowest common level of classification. Finer level
analyses were possible for some regions within the project area, such as along the lower
reaches of Janes Creek/McDaniel Slough.
We attempted to locate and record every significant shrub and small tree. We
recorded the UTM coordinates of the center of each shrub or tree using hand-held GPS
receivers. The length and width of each shrub/tree patch was then paced to the nearest
0.5-meter and recorded. Each plant was classified as either a thicket/clump or individual
runners of vine strands (e.g., of Rubus). Area of the thickets/clumps were calculated
using the formula for the area of an ellipse (A= π * ( a / 2 * b / 2) ) where a and b are the
major and minor axes (if a = b then A = π r2). In some cases where shrubs were clearly
4
triangular or rectangular the appropriate area calculations were used. Areas for
individual runners were estimated at 0.1 m2. These areas were summed for important
shrub species as a measure of shrub cover.
We obtained a vegetation GIS layer and a digital elevation map from Brian Kang
of the City of Arcata. These were converted to the NAD27 (continental U.S.) datum and
layered over a true-color photo mosaic of Humboldt Bay obtained from the USFWS
(1997) using ArcView3.2®. The vegetation layer distinguished 9 vegetation types (Table
1). After the plant surveyors had amassed considerable field time in the project area and
had studied habitat classification systems in the classroom, we cross-walked these 9
vegetation types to habitat types and stages as described by the California Wildlife
Habitats Relationship System (CWHR; Mayer and Laudenslayer 1988; Table 1). We
then recoded each polygon in the GIS vegetation layer to correspond to the CWHR
system, occasionally splitting a polygon if our findings suggested it was comprised of
two or more distinct habitat types. The area (and % of the total area) of each habitat type
and stage was calculated from the resulting map (Fig. 2). Lastly, the plant surveyors
characterized the presence or absence of 124 “habitat elements” recognized by the
CWHR system (Table 2).
Potential Vegetation
To predict potential vegetation likely to occur in the MSPA resulting from each
habitat management scenarios, we relied heavily on three sources of information – one
source of elevation data and two sources of data on the distribution of vegetation in
relation to elevation. First, we used the City’s digital elevation map of the area with
contours at 1 foot intervals in mean sea level (MSL) and a GIS layer of spot elevations
(to 0.01 foot MSL). Details concerning the input data for these data layers are available
from the City of Arcata. Second, we used descriptions of plant distribution and marsh
vegetation types in relation to tidal elevation from a Master’s thesis by A. L. Eicher from
HSU (1987). Eicher’s thesis describes the distribution of locally important salt marsh
plants in relation to mean-low-low-water (MLLW), which is the long-term average of
daily low tide heights during each low lunar tide cycle. Her plant distribution data are
reproduced in Appendices 2 & 3. To convert MSL to MLLW, we used the local
5
correction of MSL = MLLW-3.74 ft, which was provided by the Woodley Island office
of the National Oceanic and Atmospheric Administration (NOAA). This approach
suggested that salt marsh should grow down to a lower elevational threshold of 2.0 feet
(MSL), which fortunately corresponded well to the 1-foot contour digital elevation map.
Unfortunately, Eicher’s data were from the mid 1980’s and plant distributions, especially
that of Spartina densiflora, have changed significantly in the last 20 years. Therefore, we
used the 1997 aerial photo of the MSPA as our third source of information. We
determined the elevation of the “edge” of the current salt marsh outside the McDaniel
Slough area by overlaying the spot elevations of the MSPA with the aerial photo, and
tracing the salt marsh’s edge. Only 3 spot elevation points “lined-up” with the edge the
salt marsh, but there were consistently 2.82 feet above MSL in elevation (Fig. 3).
Therefore, we used 2.8 feet (MSL) as a second possible lower threshold for salt marsh.
We modeled three different habitat management scenarios. We based the first
scenario on Alternative 4, which involves building freshwater ponds in the western area
of MSPA and breaching levees to allow salt marsh elsewhere (Fig. 1). Communication
with the City of Arcata indicated that the most recently preferred plan involves a
narrower breach in the bay-side levee than depicted in Fig. 1, which would constrain the
passage of salt water into and out of the MSPA, creating a “muted” tidal flow. Plants
would likely grow lower in elevation under a muted tidal flow (Long and Mason 1983),
therefore, we used 2.0 feet as the predicted lower elevational threshold for salt marsh in
this scenario, which we termed “Alternative 4 – muted.” The second management
scenario we modeled was identical to the first except with the modification of a wider
breach in the bay-side levee (as depicted in Fig. 1). A wide breach would allow free
passage of salt water into and out of the MSPA, creating a “full” tidal flow much like
what exists on the bay side of the levees. Therefore, we used 2.8 feet (which corresponds
to the current bay-side salt marsh distribution) as the predicted lower threshold for salt
marsh for this scenario, which we termed “Alternative 4 – full.” The third management
scenario was one we informally discussed as a class and was meant to provide a
compromise between losing grasslands valuable for raptors and providing appropriate
tidal habitat for important salt marsh plants. The scenario is identical to Alternative 4muted except that a levee would be built connecting the bay-side levee to the levee at the
6
corner of V-street and Old Samoa Blvd, thereby retaining the grasslands in the western
area of MSPA and eliminating the need for the levee along the far western boundary (Fig.
4). For lack of anything better, we termed this third scenario the “Green & Gold”
scenario.
For all three scenarios, elevation contours were digitized into polygons using
ArcView3.2®. Each polygon was then coded to a CWHR type and stage as determined
by its elevation and position relative to existing, proposed, and breached levees. The
CWHR habitat types, stages, and corresponding elevations are provided in Table 5, and
we provide corresponding “common names” for vegetation types that are consistent with
salt marsh literature (Long and Mason 1983, Eicher 1987). In the northeast corner of the
MSPA, we deleted the contours entirely and created new polygons corresponding to the
brackish pond, freshwater ponds, and wooded habitat proposed by the Alternative 4 and
the Green & Gold scenarios. Because the digital elevation map only distinguished 1-foot
intervals, we used the spot elevation data to manually trace a new contour corresponding
to 2.8 feet. Rather than shift all plant distributions correspondingly, we simply
constrained the distribution of “salt marsh-low” to 2.8-3 feet, then resumed “salt marshmid” at 3 feet. This work resulted in three new GIS vegetation layers, once for each
scenario, which were used to calculate the area (and % of the total area) of each habitat
type and stage for each scenario.
Wildlife Surveys
For wildlife surveying purposes, four vegetation strata were defined in the project
area: pasture, perennial grassland, riparian & slough, and coastal scrub (e.g., Rubus and
Baccharis). From 1 to 23 March 2002, each of the four strata was surveyed for species
composition four times a week, twice in the morning and twice in the late afternoon.
Birds were surveyed using strip transects and area searches while mammals were
surveyed using track plates. Other vertebrates such as amphibians were not surveyed.
Due to the short time for data collection, additional species were included in the final list
from other observations and previous studies (e.g., Dunk 1992, Harris 1996).
To compare the wildlife community of the MSPA to that of a salt marsh, we also
conducted surveys at the mouth of the Jacoby Creek (Fig. 5). This representative salt
7
marsh plot was chosen over the small area of salt marsh on the south edge of the MSAP
because of the latter’s small size and potentially large wildlife influence from the upland
habitats of the MSPA. The Jacoby creek salt marsh is 16.95 ha in area and is only 1.8
kilometers east of the MSPA. We felt that this allowed for a higher quality comparison
in relation to the proposed restoration goal.
The riparian & slough, coastal scrub, and salt marsh strata were surveyed using a
strip transect of various lengths (Fig. 5) as described by Ralph et al. (1993). An observer
began at one end of the stratum and walked along the edge recording all birds
encountered within ten meters of the stratum. Birds noted outside the 10-meter boundary
of the stratum being searched were recorded separately and used only for species
composition of the entire study area. The same side of the stratum was surveyed each
time to ensure consistency. Flags were placed at 50-meter intervals along the transect and
the observer aimed to pass a flag every five minutes. In the salt marsh habitat, it was
noted whether the tide height was high or low.
The pasture and perennial grassland strata were surveyed following an area search
method described by Ralph and Hollinger (2001). The perennial grassland search area
was 0.35 ha larger than the pasture search area (Fig. 5). For each count, 1-2 observers
walked haphazardly around the search area for 20 minutes identifying and recording all
species encountered within the area’s boundary. Birds noted outside the stratum search
area were recorded separately and used only for species composition of the entire study
area.
Raptor counts were also conducted from near the center of the perennial grassland
(Fig. 5) before three of the afternoon surveys to obtain average abundances. A spotting
scope was set up at this location and all raptors and Turkey Vultures detected in the study
area were noted. Due to the trees of the riparian corridor, raptors flying in the pasture
habitat were not visible to the observer. Five scans were conducted over twenty minutes
and the highest count for each species was recorded.
Mammal species were surveyed using seven track plates distributed amongst the
strata for a total of 28 track-plate nights (Zielinski and Kucera 1995). Two were placed
in the perennial grassland and two along the riparian while the salt marsh, slough, and
coastal scrub received one a piece. The pasture plot did not receive any track plates due
8
to the threat of equipment damage by cattle. For track plate analysis, all habitats within
the MSPA were lumped due to the insufficient sample size. Each plate was baited with
chicken or fish during late afternoon surveys and checked the following morning. On the
last survey day of the week, all plates and contact paper were removed from the field. In
addition, physical remains, tracks, and scat were identified in the field and recorded.
Small mammal information was gathered from previous literature (Dunk 1992).
The species diversity between the MSPA and the Jacoby Creek salt marsh were
analyzed using a Shannon-Weaver index (Stiling 1999). Due to tidal differences in
species composition at the salt marsh, the high and low tide communities were analyzed
separately. We used rarefaction procedures (Simberloff 1978) to subsample the MSPA
and high tide salt marsh datasets because of biases associated with unequal numbers of
individuals detected between the habitats. Rarefaction calculations were performed with
an on-line rarefaction calculator maintained by John Brzustowski in the Biology
Department of the University of Alberta (2002).
We compared the results of the wildlife surveys to the species list generated for
the MSPA by a CWHR (version 7.0) model run using the input data for existing
vegetation habitat types, stages, and elements as determined by the current vegetation
surveys (see Wildlife-Habitat-Modeling below). For the bird and mammal lists, we
consulted ornithologists and mammalogists (see acknowledgments on page 2) to
eliminate species from the model lists that were considered unlikely to occur in the study
area once every ten years. Modeling errors of omission (detected but not predicted by the
model) and commission (predicted but not detected) were tabulated, and a Jaccard index
of community similarity (Stiling 1999) was used to compare our observed species list
with the predicted results from the CWHR model.
Wildlife-Habitat-Modeling
To model the effects of the three management scenarios, we used the CWHR
modeling program. Specifically, we used “weighted habitat comparison” reports to
model the effects of the habitat on all non-fish vertebrate wildlife. We ran three models;
each evaluated the change in “habitat value” for vertebrate species by converting the
MSPA from its current condition to one of the three management scenarios. In a
9
weighted habitat comparison, “habitat suitability” rankings (0-1) are weighted by the
percentage composition of each vegetation type. The resulting weighted “habitat values”
range from 0 to 100 for each species for each of four habitat conditions (the current
condition and conditions resulting from each of the three scenarios), with high numbers
indicating a combination of high suitability and/or high quantity of habitat. Thus, if the
habitat value of the MSPA was modeled to be 25.78 for a species in the current condition
and 12.75 with conditions resulting from the “Alternative 4 – muted” scenario, then the
change in habitat value for that species would be –13.03.
We evaluated model outputs for each vertebrate class (amphibians, reptiles, birds,
and mammals) and for each of 15 “ecological guilds” (Appendix 1). We classified each
species to guild based on available natural history information (Ingles 1965, Ehrlich et al.
1988). We used two metrics to evaluate model outputs. First, we calculated the mean
change in habitat value for each class and guild resulting from the conversion of the
current condition to conditions arising from each of the three management scenarios.
Second, we tabulated the number of species in each class and guild predicted to be
affected positively (change in habitat value ≥0) or negatively (change in habitat value <0)
by each scenario. We used chi-squared tests of independence to statistically evaluate
differences in the distribution of positively and negatively affected species among
management scenarios.
For all models, we set the suitability threshold in CWHR as “medium” or “high”
for reproductive, cover, and feeding habitat, and we set the element exclusion level at
“essential.” These choices excluded wildlife species that have low or unsuitable habitat
suitability rankings (for reproductive, cover, and feeding) for all habitats within in the
MSPA low and/or rely essentially on habitat elements not present in the MSPA.
Results
Current Vegetation
Cross-walking the City’s vegetation types to CWHR habitat types and stages
resulted in the majority of the area being classified as either perennial grassland or
pasture (Fig. 2). Our vegetation transects confirmed this general finding. The transects
yielded 5,797 points, which were classified (based on lowest common classification
10
among various students) as either “grass,” “blackberry,” “willow/alder,” “herb/forb,” or
“water.” The results indicate that, overall, the area is currently nearly 97% grass and
herb/forb, though the distribution of these broad types varies somewhat among the
CWHR habitat types of perennial grassland, pasture, and freshwater emergent wetland
(Table 3).
More precise plant classifications were made along the McDaniel Slough
waterway, where students recorded the distribution of select plant species in relation to
the distance to the tide gates at the mouth of the slough. These tide gates currently do not
prevent salt water from getting into the channels inside the levee, therefore, the fresh
water in Janes Creek and the sloughs are mixed with salt water to create brackish water.
This creates a gradient of plants species of various salt tolerances along the creek (Table
4). For example, cattail (Typha latifolia) was found along the entire creek, water parsley
(Oenanthe sarmentosa) was high on the banks near the mouth, but grew at the creek edge
past 400 meters, and salt marsh bullrush (Scirpus robustus) was found only in the first
400 meters.
Saltwater intrudes also into the perennial grassland and pasture habitats mostly
along old natural channels. Saltgrass (Distichilus spicata) is tolerant of salt water and
was found along these perennial grasslands. In total, 14 species of “wetland plants” (as
determined by the Corp of Engineers Wetlands Delineation Manual 1987, Appendix 4)
were identified in the perennial grassland, or 46.7% of the 30 total species total found.
For the perennial grassland to have a wetland rating, 50% of the plants need to be
wetland species (Corp of Engineers Wetlands Delineation Manual 1987).
Most of the shrubs and trees that we mapped were located in the VRI habitat on
the west levee of Janes Creek. The rest were scattered but tended to be concentrated
along water channels in the perennial grassland habitat (Fig. 2). Unfortunately, time
constraints did not permit us to complete the shrub mapping, though the majority of the
area west of the McDaniel Slough was surveyed (see yellow boundary in Fig. 2). Area
calculations indicated that shrub and tree cover were highest for Rubus (1.63 ha or 2.4%
cover), Baccharis (0.08 ha or 0.1% cover), and Salix (0.07 ha or 0.1% cover).
11
Potential Vegetation
All three management scenarios involve dramatic shifts in the habitat composition
of MSPA relative to its current condition (Table 5, and compare Fig. 2 to Figs. 6-8). The
total project area is approximately 103 ha, of which nearly 93% is currently perennial
grassland or pasture. Under an “Alternative 4” scenario, much of these grasslands would
be converted to some other habitat. Because a significant portion of the area inside the
bay-levee is currently lower in elevation than the bay, much of the grassland would be
converted to tidally flooded mudflat after breaching the levees. However, the
proportional contribution of mudflat after breaching varies significantly with the variation
in the predicted lower threshold of the salt marsh growth. Roughly 50% of the area is
predicted to be mudflat under a muted tidal regime (2.0 foot salt marsh threshold),
whereas 76% is predicted to be mudflat with a full tidal flow (2.8 foot salt marsh
threshold) (Table 5). Likewise, the extent of low salt marsh also varies considerably with
variation in the predicted lower threshold; over 36% of the area would be some form salt
marsh with a 2.0 foot threshold (muted flow), but only 11% would be salt marsh with a
2.8 foot threshold (full flow) (Table 5).
Under the Green & Gold scenario, much the lowest elevation area in the
southwest area of MSPA would be diked and maintained in roughly its current state.
Thus, 40% of the area would be retained in perennial grassland, 29% would be converted
to some form of salt marsh, and only 15% would be converted to mudflat (Table 5).
Wildlife Surveys
Species richness was higher in the MSPA than in the representative Jacoby Creek
salt marsh (Table 6). The Shannon-Weaver index corroborates the simple species
richness counts by showing a higher diversity in the MSPA than in the salt marsh at
either high or low tide. Rarefaction of these three habitats shows that the MSPA is still
the most diverse even after subsampling to equalize sample sizes (i.e., number of
individuals detected) (Fig. 9). Amongst the four individual habitat strata surveyed in the
MSPA, the riparian stratum was the most diverse according to a Shannon-Weaver index
followed by coastal scrub, perennial grassland, and pasture. The raptor surveys indicated
12
a moderate population density for two species and the occurrence of four others (Table
7).
The CWHR model predicted that a total of 168 bird species should occur in the
MSPA (after removal of unlikely species, Appendix 1). Forty-nine species were shared
between the CWHR bird list and our observed detections while there were 8 omission
and 119 commission errors (Table 8). Models often produce high commission error rates
(Boone and Krohn 2002), but the low values shown by the Jaccard index suggest that the
CWHR model output was relatively poorly correlated with our field data (Table 8).
Five mammal species were identified in the MSPA during our fieldwork
(Appendix 1). A literature search revealed four more mammal species detected in the
MSPA that were not detected during our surveys. The CWHR model predicted a total of
36 mammal species after removal of unlikely species (Appendix 1). All nine species
detected during our field surveys (or revealed by literature) were shared by the CWHR
model prediction (= zero omission species). There were 27 commission species (Table
8). The Jaccard index was also low for the mammal data, which again reveals a relatively
poor correlation between the CWHR model and our field surveys (Table 8).
Wildlife-Habitat-Modeling
The three management scenarios resulted in changes in habitat value for 314
wildlife species (Table 9). Of these, 62 were considered unlikely to occur in the MSPA
once in ten years (based on expert opinion, see methods) and were excluded from
subsequent analyses. The remaining 252 species were comprised of 10 amphibians 7
reptiles, 197 birds, and 38 mammals.
Alternative 4 – muted tidal flow scenario. Under this scenario, the mean habitat
change from current to modeled conditions resulted in negative effects for amphibians,
reptiles, and mammals (Table 10). Birds showed only a slight positive overall effect,
though nearly twice as many bird species were positively (130) as negatively (67)
affected.
Among herptile guilds, the effects were fairly consistent regardless of terrestrial
or aquatic guilds, with roughly 60% of each guild negatively affected. Notable species
negatively affected included the Pacific tree frog (habitat value change –72.9) and
13
common garter snake (-57.3). Positive affects were much less dramatic and arose mainly
due to the creation of new freshwater ponds. The most positively affected species
included the rough-skinned newt (+8.6) and the Northwestern salamander (+6.8).
Among bird guilds, all shorebirds and all but three waterbirds were positively
affected, with the strongest benefits to species likely to use mudflats such as Marbled
Godwits and sandpipers as well as several species of gulls and terns (generally >+30 in
habitat value). Cattle Egrets are “waterbirds” more closely associated with upland
habitats, and thus showed predictably negative effects (-41.7). Raptors and upland birds
were also strongly negatively impacted. Eighteen of 22 raptors were predicted to be
negatively affected by this scenario, with notable declines in habitat value for several
raptor species currently conspicuous in the area: Short-eared Owl (-30.5), Northern
Harrier (-18.0), and four species of Buteo hawks (-11 to -47). White-tailed kites, also
currently very common in the area, showed a less dramatic effect (-7.7) because the
CWHR model considers salt marsh habitat suitable foraging habitat for this species.
Waterfowl showed variable responses, with a comparatively similar number of species
positively and negatively affected (16 and 14, respectively). In general, waterfowl
adapted to use saline habitats, such as Brant and Greater Scaup, showed positive
responses (+43.7 and +34.1, respectively), while those often associated with freshwater
and/or grasslands showed negative impacts, such Gadwall and Northern Shoveler (-28.8
and –32.5, respectively). Among songbirds and their allies, Song Sparrows (+25.6),
Marsh Wrens (+19.2), and American Pipits (+20.7) all showed substantial positive
responses, while many other (45 species) showed modest positive responses. Western
Meadowlarks, Red-winged Blackbirds, and two species of locally uncommon upland
sparrows (Lark and Grasshopper) were most negatively affected (all <-40 habitat value),
while many others (27 species) showed more modest negative responses.
Among mammals, most (24 of 38) were negatively affected regardless of guild,
though more bats were positively than negatively affected, and two carnivores showed
significant positive effects, the river otter (+36.5) and mink (+45.5). The one marine
mammal, the harbor seal, was very positively affected (+51.2). Insectivores and small
rodents were especially negatively affected, including the currently superabundant
California vole, which showed a substantial loss of habitat value (-59.1).
14
Alternative 4-full tidal flow scenario. The modeled wildlife responses to this
scenario were very similar to those of the Alternative 4-muted flow scenario (Table 10)
even though the two scenarios differ markedly in the predicted extent of salt marsh versus
tidal mudflat habitats (Table 5). The similarity in modeled wildlife responses thus
reflects the fact that mudflats and salt marshes provide habitat for relatively few wildlife
species. Like with the Alternative 4-muted flow scenario, the mean habitat change for
this scenario was negative for amphibians, reptiles, and mammals, but slightly positive
for birds (Table 10). Among herptile guilds, the effects were identical to those of the
Alternative 4-muted flow scenario.
Among bird guilds, shorebirds and waterbirds were again very positively affected,
but slightly more so than in the muted scenario because, in general, mudflat provides
more habitat for these species than does salt marsh. Raptors and upland birds (mainly
quail) were again strongly negatively impacted. Because the full flow scenario has less
salt marsh, the negative effects were more pronounced than in the muted scenario for
those species that may occasionally use salt marsh as foraging habitat (e.g., -15.9 for
White-tailed Kite). Waterfowl again showed variable responses, but in general were
slightly more exaggerated because of the fuller tidal cycle and more exposed mudflat.
For example, puddle ducks that were negatively affected under the muted scenario (e.g.,
Mallard and American Wigeon) were more negatively affected under full flow scenario
due to their modest use of salt marsh habitats but avoidance of tidal mudflats. Songbirds
also showed highly variables responses, but this time Song Sparrows and Marsh Wrens
were much less positively affected (+6.4 and + 2.7, respectively), because of the
substantial decrease in quantity of salt marsh habitat with this scenario relative to the
muted cycle. As before, grassland-associated species (e.g., Western Meadowlarks) were
very negatively affected.
Like with the Alternative 4-muted flow scenario, most mammals (26 of 38) were
negatively affected regardless of guild. Species reliant on grasslands were again severely
negatively impacted (e.g., Botta’s pocket gopher –89.4). Species unlikely to use mudflat
were even harder hit than with the muted flow scenario. For example, the California vole
showed a more dramatic loss of habitat value under the full than the muted scenario (75.6). The comparatively more tidal flat, however, resulted in a slightly more positive
15
effect on the harbor seal (+51.2). Insectivores were again very negatively affected (–
58.53 mean habitat change).
Green & Gold scenario. Under this scenario, the retention of perennial grassland
habitats resulted in substantially different modeled wildlife responses (Table 10).
Overall, negative effects were dampened relative to the other two scenarios for
amphibians, reptiles, and mammals (Table 10). Birds showed a slightly stronger positive
overall effect, and over three times as many species were positively (150) as negatively
(47) affected.
Among herptile guilds, the effects were fairly consistent with the other scenarios,
with over half of the species negatively affected regardless of guild. However, the
average decline in habitat value was substantially less for both guilds as compared to the
other two scenarios (Table 10).
Among bird guilds, shorebirds and waterbirds were again positively affected, but
not as dramatically as under the other scenarios. This was especially true for shorebirds,
which responded favorably to the mudflat habitat created under the other scenarios but
which is comparatively rare under the Green & Gold scenario. The retention of grassland
habitats was perhaps most beneficial for raptors: roughly similar numbers were positively
and negatively affected under this scenario, in contrast to their strongly negative
responses to the other two scenarios. Quail were also less negatively affected under this
scenario. Waterfowl showed on average more favorable responses to this scenario than
the others, though the aforementioned species that utilize salt marsh (e.g., Brant and
Greater Scaup) showed dampened positive effects. Among songbirds and their allies,
there were more positive responses (56 species) than with the other two scenarios. Song
Sparrows and Marsh Wrens showed the most substantial positive effects (+22.1 and
+16.8, respectively). Grassland-affiliated species (e.g., Western Meadowlarks and some
sparrows) were again negatively affected, but less so than under the other scenarios.
Pasture-affiliated species (e.g., Brewer’s Blackbirds), remained similarly negatively
affected (-22.9) because of the consistent removal of existing pasture habitat under all
three scenarios.
Among mammals, again many were negatively affected (23 of 38), though fewer
than under the other scenarios. Bats, large rodents & allies, and ungulates responded
16
fairly similarly as they did in the other scenarios, but among insectivores, the vagrant
shrew showed a positive response to this scenario, whereas it showed negative responses
to the others. Carnivores responded less negatively to this scenario, including a positive
effect for bobcat, which had previously shown only negative responses. Small rodents
still showed substantial negative effects, though less so than under the other scenarios.
For example, California voles showed a comparatively small negative response (-25).
In sum, the three management scenarios yielded somewhat different modeled
effects on wildlife species (Fig. 10). The two variations on Alternative 4 – muted tidal
flow and full tidal flow – showed similar overall effects (χ2 = 0.03, df = 1, P = 0.86),
though particular species were significantly affected by the proportionally higher
abundance of salt marsh and lower abundance of tidal mudflat under the muted scenario.
By retaining grasslands over mudflat, the Green & Gold scenario showed more positive
and fewer negative effects than either the Alternative 4-full flow (χ2 = 4.61, df = 1, P =
0.03) or the Alternative 4-muted flow scenarios (χ2 = 3.86, df = 1, P = 0.05). In
particular, the effects were less negative for herptiles, raptors, mammalian insectivores,
rodents, and ungulates. However, the effects of the Green & Gold scenario were also less
positive for shorebirds, waterbirds, and the harbor seal.
Discussion
The results of our modeling suggest the proposed salt marsh restoration will have
dramatic effects on the wildlife of the MSPA. The Green & Gold scenario offers the
most positive wildlife responses, followed by the Alternative 4-muted and then the
Alternative-4 full flow scenarios (Fig. 10). There are more species positively than
negatively affected by all three modeled scenarios, though many positive responses stem
from the creation of new freshwater ponds and riparian woodlands and not the creation of
salt marsh. Salt marsh supports relatively few wildlife species (Mayer and Laudenslayer
1988), as verified by our wildlife surveys (Fig. 9).
The effects of the proposed restoration scenarios on wildlife vary greatly by
ecological guild. Guilds reliant on grassland habitats (e.g., rodents, raptors, insectivores,
grassland songbirds) would be especially negatively impacted by both the Alternative 4muted and full flow scenarios (Table 10). The Green & Gold scenario greatly mitigates
17
these losses by retaining some perennial
grassland habitat at the expense of less
mudflat. Shorebirds and, to a lesser extent,
waterbirds respond favorably to the creation
of mudflat and thus were less positively
affected by the Green & Gold scenario than
Short-eared owl
(Asio flammeus)
either Alternative 4 scenario.
Our modeling results should be interpreted with caution, because the tidal
elevational threshold below which salt marsh will not become established profoundly
influences all predictions of a proposed breaching of levees along the bay. If that
threshold is close to 2.0 feet MSL (as reported in
Eicher 1987 and which may occur under a muted
tidal flow), then roughly 36% of the MSPA is
predicted to revert to some form of salt marsh after
the levees are breached. However, if the lower
threshold is 2.8 feet (as suggested by the current
distribution of salt marsh outside the bay-side levee
and which may occur with a full tidal flow), then
only 11% of the MSPA would be salt marsh, and
over 75% would exist as mudflat too low to support
Tidal mudflat
wetland plants (Table 5). A better understanding of
the distribution of salt marsh with elevation and a
better prediction of how soil within the MSPA may expand after flooding is critical to
evaluate the potential impacts of the proposed project on plant and animal life in the area.
Our elevational analyses also suggest that a relatively small area of the MSPA is
at an elevation favorable the Humboldt Bay owl’s clover (Castilleja ambigua spp.
humboldtiensis) and the Point Reyes bird’s beak (Cordylanthus maritimus spp. palustris),
two locally important salt marsh plants. According to Eicher (1987), these two species
reach peak cover roughly between 4 and 6 feet MSL. Assuming no expansion of the soil
after flooding (which needs to be addressed by qualified soil ecologists), our model
suggests that only about 6% of the MSPA will provide favorable habitat for these species
18
Cord grass
(Spartina densiflora)
– and this value does not change significantly among the three scenarios we modeled.
The remaining salt marsh is too low for these species and would likely be dominated by
Salicornia virginica and/or Spartina densiflora. We optimistically modeled Salicornia as
dominant from 2-3 feet (2.8-3 feet in the full-flow scenario) based on Eicher’s data from
the mid 1980’s. Since that time, Spartina densiflora has expanded dramatically,
including in low and high salt marshes (USFWS, pers. com.). Spartina densiflora
expansion is particularly problematic
Cordgrass
(Spartina densiflora)
in disturbed area, such as recent
restoration sites. Although the
USFWS has found some success
controlling the expansion of Spartina
densiflora via intensive manual
removal on small experimental plots,
without such costly management it
could very well come to dominate
nearly all of any salt marsh habitat
created by the proposed restoration of the MSPA. The project’s objectives include low
cost maintenance. Therefore, the managing entities should consider seriously the
acceptability of one of the following two alternatives: a) Spartina densiflora expansion
throughout the restored salt marsh, or b) the considerable cost to exclude Spartina
densiflora from low (< 3 feet) and high (>5 feet) areas of the marsh. If neither of these is
acceptable, the proposal should be reconsidered, because the control of Spartina
densiflora at little cost appears unlikely.
By providing freshwater ponds, salt marsh, and retaining some perennial
grassland, the Green & Gold scenario clearly has more positive wildlife effects than does
either of the two Alternative 4 scenarios. Moreover, because the area modeled to be
retained as grassland is relatively low in elevation, most of it would only become mudflat
of little botanical and modest wildlife value under the other scenarios. In fact, the
predicted cover of salt marsh declines only 8% from the scenario maximizing salt marsh
(Alternative 4 –muted) to the Green & Gold scenario (Table 5). Thus, the Green & Gold
scenario appears to provide benefits of grassland habitat with little price in salt marsh.
19
However, this report does not evaluate flood control issues, and a qualified hydrologist
should evaluate how the Green & Gold scenario could help alleviate flooding concerns,
perhaps by installing operable flood gates along the grassland levee, allowing it to flood
during rare high tides coincident with winter storms.
Our wildlife surveys confirmed that salt marsh provides habitat for
relatively few species (Fig. 9), but our surveys also revealed a relatively weak correlation
between predicted (based on CWHR models) and observed species occurrence in the
MSPA (Table 8). The very high commission error rate can be partially explained by the
fact that our surveys were only conducted in March and thus were unable to fully
document the species present in the project area. In addition, these errors may arise from
the relatively small spatial scale of the project (~100 ha). Raphael and Marcot (1986)
have indicated that models such as CWHR are most useful for determining the
occurrence of species in general vegetation types over a large region and less useful in
small areas. A more serious concern, then, is over omitted species (detected but not
observed), which can misdirect management efforts (Garrison et al. 1999). We
documented eight bird species that were not predicted (omission errors; e.g., Doublecrested Cormorant, Bufflehead, Peregrine Falcon, Black-capped Chickadee, and Nelson’s
Sharp-tailed, Fox, White-throated and Swamp Sparrows). Moreover, there were several
species that experience suggests could be found in the MSPA but were not included in
the predicted lists (e.g., Red-breasted Nuthatch, Vaux’s Swift). These errors may arise in
the CWHR’s level of geographic precision. Its predictions are derived from habitat
association and then modified by the assemblage of species by county. Thus, when we
queried it for grasslands in Humboldt County, it has no way to distinguish coastal
grasslands (as in the MSPA) from more inland grasslands (e.g., along the Bald Hills in
Redwood National Park). Nonetheless, models provide means of quantifying responses
of proposed land use actions before they are conducted, and their general results, more
than species-by-species predictions, can often be helpful for management decisions
(Morrison et al. 1998, Roloff et al. 2001). For example, our CWHR analyses clearly
indicated that both Alternative 4 scenarios would negatively affect all raptors, grassland
birds, and small rodents and mammalian insectivores, while waterbirds would be
positively affected.
20
We did not model any alternatives that leave the entire grassland intact or create
Humboldt
Bay owl’s
new additional freshwater ponds in lieu of creating
a restored
saltclover
marsh. Although both
(Castilleja ambigua ssp. humboldtiensis)
of these non-restoration alternatives would likely have higher non-fish vertebrate value
than any of the scenarios modeled here, it is
very important to recognize the contribution
Humboldt Bay owl’s clover
(Castilleja ambigua ssp. humboldtiensis)
of regionally rare salt marsh habitat and its
associated plant species to biodiversity at
large spatial scales. Land managers
sometimes focus on local diversity (which
could probably be maximized in MSPA by
creating more freshwater habitat) at the
expense of managing for habitats that
contribute little to local diversity (e.g. salt marsh) but make substantial contributions to
“gamma diversity” – that is, the diversity across an entire region (Noss et al. 1997). In
this context, endemic taxa take precedence over ubiquitous species. In the case of
MSPA, the endemic plants make much more substantive contributions to gamma
diversity than do virtually any of the wildlife species and are therefore elevated in
importance.
Literature Cited
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assessment. Pages 265-270 in Predicting species occurrences issues of accuracy
and scale. J. M. Scott et al. (eds.). Island Press, Washington D.C.
California Native Plant Society. 2001. “Let’s prioritize salt marsh restoration for
McDaniel Slough.” Arcata Eye. 13 March 2001.
Dunk, J. 1992. Black shouldered kite – small mammal vegetation relationships in north
western California. Humboldt State masters thesis.
Eicher, A. L. 1987. Salt marsh vascular plant distribution in relation to tidal elevation.
M.A. Thesis. Humboldt State University, Arcata, California.
Harris, S. W. 1996. Northwestern California Birds, 2nd edition. Humboldt State
University Press, Arcata, California.
21
Harris, S. W. 2001. “The Janes Creek/McDaniel Slough Project.” Arcata Eye. March
2001.
Higgins, K. F., J. L. Oldemeyer, K. J. Jenkins, G. K. Clambey, and R. F. Harlow. 1996.
Vegetation sampling and measurement. Pages 567-591 in Research and
Management Techniques for Wildlife and their Habitats, T. A. Bookhout (ed.).
The Wildlife Society, Bethusda, Maryland.
Long, S. P. and C. F. Mason. 1983. Salt marsh ecology. Blackie, Glasgow and London,
United Kingdom.
Mayer, K. E. and W. F. Laudenslayer. 1988. A guide to wildlife habitats of California.
California Department of Forestry and Fire Protection, Sacramento, California.
166 pp.
Morrison, M. L., B. G. Marcot, and R. W. Mannan. 1998. Modeling Wildlife-Habitat
Relationships. Pp. 309-349, in Wildlife-Habitat Relationships. The University of
Wisconsin Press, Madison, Wisconsin. 435 pp.
Noss, R. F., M. A. O'Connell, and D. D. Murphy. 1997. Chapter 1, "Species and
habitats" in: The Science of Conservation Planning: habitat conservation under
the endangered species act. Island Press, Washington, D.C.
Ralph, C. John and K. R. Hollinger. 2001. A Draft of the Redwood Sciences Laboratory
and the Klamath Demographic Monitoring Network Mist-netting Station
Management Procedures. Redwood Sciences Lab, Arcata, CA.
Ralph, C. J. et al. 1993. Handbook of Field Methods for Monitoring Landbirds. Pacific
Southwest Research Station. Albany, CA.
Raphael, M. G., and B. G. Marcot. 1986. Validation of a wildlife-habitat-relationships
model: Vertebrates in a Douglas-fir sere. Wildlife 2000: Modeling habitat
relationships of terrestrial vertebrates, ed. J. Verner, M. L. Morrison, and C. J.
Ralph, 129-38. Madison: University of Wisconsin Press.
Ricklefs, R. E. 1990. Ecology, 3rd edition, W. H. Freeman and Co., New York.
Roloff, G. J., G. F. Wilhere, T. Quinn, S. Kohlmann. 2001. An overview of models and
their role in wildlife management. Pages 168-186 in D. H. Johns, T. A. O’Neil
eds. Wildlife-habitat relationships in Oregon and Washington. Oregon State
University Press, Corvallis, Oregon.
22
Simberloff, D. S. 1978. Use of rarefaction and related methods in ecology. In K.L.
Dickson, J. Cairns, Jr., and R.J. Livingston (eds.), Biological Data in Water
Pollution Assessment: Quantitative and Statistical Analyses pp. 150-165.
American Society for Testing and Materials STP 652, Philadelphia.
http://www.biology.ualberta.ca/jbrzusto/rarefact.php
Stiling, P. 1999. Ecology: theories and applications. 3rd ed. Prentice Hall, New Jersey.
Williams, J., S. Weber, and D. Hull. 1984. The Arcata Marsh Primer II. City of Arcata.
Zielinski, W. J. and T. E. Kucera. 1995. A detection manual for wolverine, fisher, lynx
and marten in the western United States. Gen. Tech. Report, USDA Forest
Service, Pacific Southwest Research Station, PSW-GTR-157. 163 pp.
23
Table 1. Vegetation types distinguished in a City of Arcata vegetation map of the
McDaniel Slough Project Area (MSPA) and their corresponding California Wildlife
Habitats Relationships System (CWHR) habitat types and stages.
CWHR Habitat Types
CWHR Habitat Stages*
Perennial grassland (PGS) and Pasture (PAS)
2M, 2D
Aquatic
Fresh emerent wetland (FEW)
1S, 2M, 2D
Brackish marsh
Fresh emerent wetland (FEW)
1S, 2M
Vegetation Type
Agricultural field
Developed
Freshwater marsh
Mud flat
Ruderal/upland
Salt marsh
Willow riparian
*
Fresh emergent wetland and Valley foothill
riparian (VRI)
Modeled as building elements
within other habitat types
2M, 2D and 3M
Estuarine (EST)
3M
Coastal scrub (CSC)
3S
Saline emergent wetland
2D
Valley foothill riparian (VRI)
3M
Stages refer to the size (numeral) and cover (letter) of the habitat. For herbaceous
habitats, 1 and 2 size codes correspond to < and > 12” in height, respectively. For shrubdominated habitats (costal scrub), size code 3 corresponds to mature shrubs (1-25%
crown decadence). For tree-dominated habitats, size code 3 corresponds to pole trees (611” trunk diameter at breast height). For herbaceous habitats, cover codes S, M, and D
correspond to sparse (2-9%), moderate (40-59%), dense (60-100%) cover respectively.
For shrub- and tree-dominated habitats, cover codes S, M, and D correspond to sparse
(10-24%), moderate (40-59%), dense (60-100%) cover respectively (open cover classes,
25-39% cover, were not present in the study area). These designations follow the CWHR
protocol (Mayer and Laudenslayer 1988).
24
Table 2. Habitat elements modeled for the McDaniel Slough Project Area for current conditions and under
3 habitat management scenarios (see text for details of each scenario). An X indicates presence, empty
indicates absence. Scenario abbreviation are CC = current condition, A4F = Alternative 4—full flow, A4M
= Alternative 4—muted flow, GG = Green & Gold scenario. See text for details.
Element
Scenario
CC A4F A4M GG
Acorns
Algae
Amphibians
Aquatics,
emergent
Aquatics,
submerged
Bank
Barren
Berries
Birds, large
Birds, medium
Birds, small
Bogs
Brush piles
Buildings
Burrows
Layer, shrub
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Campground
Carrion
Element
X
X
X
X
Layer, tree
Lichens
Lithic
Litter
Duff
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Dump
Eggs
Fences
Fern
Fish
Flowers
Forbs
Fruits
Fungi
Grain
Graminoids
Grass/agricult.
Grass/water
Insects, flying
Insects,
terrestrial
Invertebrates
Invertebrates,
aquatic
Jetty
Kelp
Lakes
Layer,
herbaceous
X
X
X
X
X
Snag, large
sound
Snag, med.
Rotten
Snag, med.
sound
Snag, sm. rotten
Soil, aerated
Log, large sound
Log, med. hollow
Log, med. rotten
Log, med. sound
Mammals, large
Mammals, med.
Mammals, small
Soil, friable
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Mine
Moss
Mud flats
Nectar
Nest island
X
X
X
X
X
X
X
Log, large rotten
Nest box
X
X
X
X
X
X
X
Snag, sm. sound
Cliff
X
X
X
X
X
X
X
Element
Log, large hollow
Cave
Cones
Scenario
CC A4F A4M GG
Soil, organic
Soil, saline
Soil, sandy
Streams,
intermittent
Streams,
permanent
Stump, rotten
Stump, sound
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Salt ponds
Sand dune
Sap
Seeds
Shrub/agricult.
Shrub/grass
Shrub/water
Shrubs
Slash, large
hollow
Slash, large
rotten
Slash, large
sound
Slash, small
Snag, large
rotten
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Talus
Transmission
lines
Tree leaves
Roots
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Steep slope
Ponds
Rock
X
Springs, hot
Tidepools
Riparian
inclusion
Rivers
X
Springs
Pack station
Reptiles
X
Springs, mineral
Nest platform
Nuts
Soil, gravelly
Scenario
CC A4F A4M GG
Tree/agriculture
Tree, broken top
live
Tree, with
cavities
Tree, with loose
bark
Tree/grass
Tree/shrub
Tree/water
Trees, fir
Trees, hardwood
X
Trees, pine
Vernal pools
Water
Water, created
body
Water, fast
Water, slow
Water/agricult.
Wharf
Table 3. Frequency of plant groups (and % of total) at “toe points” at 5 m intervals
along transects systematically distributed throughout the grassland, pasture, and
freshwater slough vegetation strata of the McDaniel Slough Project Area (MSPA).
Vegetation Strata
Perennial
grassland
Pasture
Freshwater Slough
Total
3864 (78.2)
583 (86.9)
120 (64.9)
4567 (78.8)
Blackberry
18 (0.4)
5 (0.7)
0
23 (0.4)
Willow/Alder
13 (0.3)
0
0
13 (0.2)
Herb/Forb
908 (18.4)
76 (11.3)
65 (34.1)
1049 (18.1)
Water
138 (2.8)
7 (1.0)
0
145 (2.5)
4941
671
185
5797
Plant Group
Grass
n
Table 4. Approximate distribution of select plants along a salt-brackish-fresh water
gradient of the McDaniel Slough. Salinity increases with decreasing distance to the
mouth of the slough.
Distance upstream from mouth in meters
100 200 300 400
Saltmarsh
bullrush
Carex spp
Juncus spp
Cattail
Cinquefoil
Water parsley
Velvet grass
Teasel
Dock spp
California aster
Fescue
Pennywort
26
500
600
700
800
900 1000
Table 5. Local vegetation types of the McDaniel Slough Project Area (MSPA), their corresponding habitat types and stages of the
California Wildlife Habitat Relationships System (CWHR), elevational ranges (in feet above mean sea level, MSL), and area in the
MSPA's current condition and as predicted under 3 habitat management scenarios (see text for scenario details).
Total Area in ha (%)
CWHR
Stage*
Elevation range
(MSL)
Current
Condition
Perennial grassland PGS
2D
variable; 1-4 ft
58.7 (57)
-
-
39.7 (39)
Perennial grassland, short-moderate Perennial grassland PGS
2M
variable; 1-4 ft
1.9 (2)
-
-
-
Pasture
Pasture PAS
NA
variable; 1-4 ft
32.1 (31)
-
-
-
Salt marsh low - Salicornia
Saline emergent wetland SEW
1M
2-3 ft or 2.8-3 ft
0.7 (1)
30.4 (30)
4.8 (5)
22.4 (22)
Saline emergent wetland SEW
2D
3-4 ft
2.4
4.9
4.9
4.8
Saline emergent wetland SEW
2D
4-6 ft
0.1
1.3
1.3
1.3
Local Vegetation Type Name
Corresponding CWHR Habitat Type
Perennial grassland, tall-dense
Salt marsh mid - Spartina
Salt marsh high (mixed spp.)
**
Alternative 4 Alternative 4 Green & Gold
muted (2.0 ft) full (2.8 ft)
scenario
Salt marsh mid & high combined
Saline emergent wetland SEW
2D
3-6 ft
2.5 (2)
6.2 (6)
6.2 (6)
6.1 (6)
Slough, short-sparse
Fresh emergent wetland FEW
1S
0-1 ft
2.0 (2)
-
-
2.0 (2)
Slough, tall-sparse
Fresh emergent wetland FEW
2M
1-2 ft
0.7 (1)
-
-
0.7 (1)
Slough/marsh, tall-dense
Fresh emergent wetland FEW
2D
variable; 1-4 ft
1.8 (2)
-
-
0.7 (1)
Riparian/mixed woodland
Valley foothill riparian VRI
3M
variable; 3-8 ft
0.9 (1)
4.9 (5)
4.9 (5)
4.9 (5)
Coastal scrub (Baccharis)
Coastal scrub CSC
3S
variable; 6-8 ft
1.5 (1)
2 (2)
2 (2)
2.2 (2)
Brackish lake
Estuarine EST
2M
-
-
2.3 (2)
2.3 (2)
2.3 (2)
Tidal mudflat
Estuarine EST
3M
< 2ft
-
50.3 (49)
75.9 (74)
15.1 (15)
Freshwater lake/marsh
Lacustrine LAC
2M
-
-
6.7 (7)
6.7 (7)
6.7 (7)
102.8 ha
102.8 ha
102.8 ha
102.8 ha
Total
*
See Table 1 for descriptions of stage abbreviations.
**
The CWHR system does not distinguish between mid and high salt marsh, both of which correspond to tall, dense saline emergent
wetland (SEW 2D). These two vegetation types are distinguished on maps (Figs. 6-8) but were lumped for modeling purposes.
Table 6. Species richness and Shannon-Weaver index results for birds in the McDaniel
Slough Project Area (MSPA) and a representative salt marsh near Jacoby Creek at low
and high tide. Number of species is based on the maximum of 12 counts conducted in
March 2002 (see Fig. 5 for count-transect locations).
Survey area/condition
# Species
Total mean Abundances
H-value
55
155
3.67
Riparian stratum
37
95
3.13
Perennial grassland stratum
17
46
2.25
Pasture stratum
6
26
1.47
Coastal scrub stratum
16
35
2.45
Salt Marsh (high tide)
39
1548
1.86
Salt Marsh (low tide)
17
77
2.37
MSPA (all strata combined)
Table 7. Average raptor abundance (number of birds) from three standardized counts
from a single central position in the McDaniel Slough Project Area (MSPA) conducted in
March 2002. Each count’s total was the highest recorded number of raptors detected
during 5 scans conducted over a twenty minute period on a single morning. See
Appendix 1 for scientific names and raptor species designations.
Species
Mean abundance
White-tailed Kite
5
Northern Harrier
4.7
Red-shouldered Hawk
1
American Kestrel
0.3
Red-tailed Hawk
0.3
Short-eared Owl
0.3
Turkey Vulture
1.3
28
Table 8. Comparison of species predicted to be present in the McDaniel Slough Project
Area (MSPA) under current conditions by CWHR with species detected via surveys
conducted in March 2002 and/or observed in earlier studies. Commission species were
predicted but not detected; omission species were detected but not predicted. Jaccard
index of similarity values are provided.
Comparison group
Birds
Mammals
Total
# Species
Predicted by
CWHR
# Species
Observed via
surveys or
Dunk
# Commission
Species
# Omission
Species
Jaccard Index
of Similarity
168
57
119
8
0.278
36
9
27
0
0.250
204
66
146
8
0.274
29
Table 9. Habitat values for every verterbrate species predicted to occur in the MSPA under its current condition and
each of the three management scenarios. See text for explanation of habitat values.
Habitat Value
Common Name
Northwestern Salamander
Rough-Skinned Newt
Ensatina
California Slender Salamander
Western Toad
Pacific Chorus Frog
Red-Legged Frog
Foothill Yellow-Legged Frog
Bullfrog
Pacific Giant Salamander
Red-Throated Loon
Common Loon
Pied-Billed Grebe
Horned Grebe
Red-Necked Grebe
Eared Grebe
Western Grebe
Clark's Grebe
Brown Pelican
Double-Crested Cormorant
Brandt's Cormorant
American Bittern
Great Blue Heron
Great Egret
Snowy Egret
Cattle Egret
Green Heron
Black-Crowned Night Heron
White-Faced Ibis
Tundra Swan
Greater White-Fronted Goose
Snow Goose
Ross' Goose
Brant
Canada Goose
Wood Duck
Green-Winged Teal
Mallard
Northern Pintail
Blue-Winged Teal
Cinnamon Teal
Northern Shoveler
Gadwall
Eurasian Wigeon
American Wigeon
Canvasback
Redhead
Ring-Necked Duck
Greater Scaup
Lesser Scaup
Oldsquaw
Surf Scoter
White-Winged Scoter
Common Goldeneye
Bufflehead
Hooded Merganser
Common Merganser
Red-Breasted Merganser
Ruddy Duck
Turkey Vulture
Osprey
White-Tailed Kite
Bald Eagle
Northern Harrier
Sharp-Shinned Hawk
Cooper's Hawk
Red-Shouldered Hawk
Red-Tailed Hawk
Ferruginous Hawk
Rough-Legged Hawk
American Kestrel
Merlin
Prairie Falcon
California Quail
Virginia Rail
Sora
American Coot
Black-Bellied Plover
Pacific Golden-Plover
Semipalmated Plover
Killdeer
Black-Necked Stilt
American Avocet
Greater Yellowlegs
Change in Habitat Value
Current
Condition
Alternative 4 muted (2.0 ft)
Alternative 4 full (2.8 ft)
Green & Gold
2.40
9.20
9.20
10.60
Current to Current to
Alt. 4 muted Alt. 4 full
6.8
6.8
Current to
G&G
8.2
1.00
9.60
9.60
9.60
8.6
8.6
8.6
0.70
3.30
3.30
3.30
2.6
2.6
2.6
1.00
5.00
5.00
5.00
4
4
4
64.00
11.40
11.40
39.20
-52.6
-52.6
-24.8
86.20
13.30
13.30
55.30
-72.9
-72.9
-30.9
44.90
6.60
6.60
35.70
-38.3
-38.3
-9.2
0.70
3.40
3.40
3.40
2.7
2.7
2.7
85.70
10.40
10.40
47.30
-75.3
-75.3
-38.4
3.00
5.00
5.00
6.40
2
2
3.4
0.90
0.90
0.90
0.9
0.9
0.9
19.80
28.00
8.60
19.8
28
8.6
20.80
9.80
21.10
14.8
3.8
15.1
1.30
1.30
1.30
1.3
1.3
1.3
0.90
0.90
0.90
0.9
0.9
0.9
7.70
38.00
15.80
34.90
30.3
8.1
27.2
3.70
27.60
38.60
15.50
23.9
34.9
11.8
3.70
27.60
38.60
15.50
23.9
34.9
11.8
39.90
1.80
1.80
27.20
-38.1
-38.1
-12.7
21.20
29.40
10.00
21.2
29.4
10
1.30
1.30
1.30
1.3
1.3
1.3
6.00
4.10
9.20
3.70
9.40
5.1
-0.4
5.3
22.20
36.60
39.40
32.90
14.4
17.2
10.7
45.20
58.90
55.90
62.90
13.7
10.7
17.7
6.60
60.70
46.70
40.60
54.1
40.1
34
27.10
-41.7
-41.7
-14.6
41.70
4.90
9.70
9.70
12.70
4.8
4.8
7.8
7.90
52.30
32.80
40.10
44.4
24.9
32.2
3.20
3.10
3.10
5.50
-0.1
-0.1
2.3
43.70
20.50
9.50
45.10
-23.2
-34.2
1.4
30.80
20.50
9.50
36.60
-10.3
-21.3
5.8
29.50
4.70
4.70
24.30
-24.8
-24.8
-5.2
29.00
3.90
3.90
23.10
-25.1
-25.1
0.30
44.00
52.60
18.70
43.7
52.3
18.4
51.10
3.10
3.10
36.80
-48
-48
-14.3
-5.9
3.20
5.60
5.60
7.90
2.4
2.4
4.7
63.10
4.70
4.70
45.80
-58.4
-58.4
-17.3
66.40
41.50
30.50
70.70
-24.9
-35.9
4.3
51.80
65.90
63.20
69.40
14.1
11.4
17.6
49.70
23.90
34.90
41.30
-25.8
-14.8
-8.4
4.50
14.70
20.20
10.70
10.2
15.7
6.2
37.20
4.70
4.70
29.40
-32.5
-32.5
-7.8
50.20
21.40
10.40
49.80
-28.8
-39.8
-0.4
29.70
20.50
9.50
35.60
-9.2
-20.2
5.9
63.30
17.70
9.50
55.80
-45.6
-53.8
-7.5
3.60
38.80
55.60
18.80
35.2
52
15.2
3.30
22.20
30.40
13.50
18.9
27.1
10.2
4.50
3.90
3.90
7.40
-0.6
-0.6
2.9
34.10
50.90
11.40
34.1
50.9
11.4
33.00
46.70
40.20
-7.6
6.1
-0.4
22.90
33.90
7.90
22.9
33.9
7.9
28.30
42.00
9.60
28.3
42
9.6
40.60
0.40
34.10
50.90
11.40
34.1
50.9
11.4
35.20
48.90
16.50
34.8
48.5
16.1
14.3
33.00
46.70
14.30
33
46.7
2.70
8.10
8.10
9.70
5.4
5.4
7
3.40
7.50
7.50
9.80
4.1
4.1
6.4
28.30
42.00
9.60
28.3
42
9.6
4.80
8.60
8.60
11.50
3.8
3.8
6.7
60.90
6.50
6.50
44.50
-54.4
-54.4
-16.4
14.6
3.70
19.60
11.40
18.30
15.9
7.7
23.30
15.60
7.40
26.80
-7.7
-15.9
3.5
1.90
23.10
23.10
14.60
21.2
21.2
12.7
67.20
49.20
29.70
75.50
-18
-37.5
8.3
14.20
4.10
4.10
12.40
-10.1
-10.1
-1.8
13.90
3.70
3.70
12.00
-10.2
-10.2
-1.9
15.60
4.30
4.30
13.90
-11.3
-11.3
-1.7
46.70
17.20
6.20
31.70
-29.5
-40.5
-15
47.20
0.90
0.90
17.60
-46.3
-46.3
-29.6
-29.8
48.20
0.90
0.90
18.40
-47.3
-47.3
21.90
11.70
6.20
23.20
-10.2
-15.7
14.50
7.90
2.40
15.20
-6.6
-12.1
0.7
60.60
5.50
5.50
43.50
-55.1
-55.1
-17.1
47.40
7.00
7.00
36.20
-40.4
-40.4
-11.2
6.00
20.50
6.80
19.20
14.5
0.8
13.2
6.10
24.10
7.40
21.80
18
1.3
15.7
6.60
51.10
45.40
34.30
44.5
38.8
27.7
1.20
36.90
42.40
16.50
35.7
41.2
15.3
1.30
46.00
51.80
20.70
44.7
50.5
19.4
32.80
49.60
10.10
32.8
49.6
10.1
1.60
42.70
51.30
18.70
41.1
49.7
17.1
2.60
46.00
51.80
21.50
43.4
49.2
18.9
2.60
52.60
52.90
26.30
50
50.3
23.7
1.3
Common Name
Lesser Yellowlegs
Willet
Spotted Sandpiper
Whimbrel
Long-Billed Curlew
Marbled Godwit
Ruddy Turnstone
Black Turnstone
Red Knot
Western Sandpiper
Least Sandpiper
Dunlin
Baird's Sandpiper
Pectoral Sandpiper
Stilt Sandpiper
Short-Billed Dowitcher
Long-Billed Dowitcher
Common Snipe
Wilson's Phalarope
Red-Necked Phalarope
Red Phalarope
Bonaparte's Gull
Heermann's Gull
Mew Gull
Ring-Billed Gull
California Gull
Herring Gull
Thayer's Gull
Western Gull
Glaucous-Winged Gull
Caspian Tern
Elegant Tern
Common Tern
Forster's Tern
Band-Tailed Pigeon
Mourning Dove
Barn Owl
Western Screech Owl
Great Horned Owl
Northern Pygmy Owl
Burrowing Owl
Long-Eared Owl
Short-Eared Owl
Northern Saw-Whet Owl
Common Nighthawk
Anna's Hummingbird
Rufous Hummingbird
Allen's Hummingbird
Belted Kingfisher
Red-Breasted Sapsucker
Downy Woodpecker
Hairy Woodpecker
Northern Flicker
Western Wood-Pewee
Willow Flycatcher
Pacific-Slope Flycatcher
Black Phoebe
Say's Phoebe
Ash-Throated Flycatcher
Western Kingbird
Horned Lark
Purple Martin
Tree Swallow
Violet-Green Swallow
Northern Rough-Winged Swallow
Cliff Swallow
Barn Swallow
American Crow
Common Raven
Chestnut-Backed Chickadee
Bushtit
Bewick's Wren
House Wren
Winter Wren
Marsh Wren
Ruby-Crowned Kinglet
Western Bluebird
Swainson's Thrush
Hermit Thrush
American Robin
Varied Thrush
Wrentit
Northern Mockingbird
American Pipit
Cedar Waxwing
Northern Shrike
Current
Condition
Alternative 4 muted (2.0 ft)
Alternative 4 full (2.8 ft)
Green & Gold
Current to Current to
Alt. 4 muted Alt. 4 full
Current to
G&G
1.30
49.10
54.90
24.20
47.8
53.6
3.90
55.50
55.60
29.50
51.6
51.7
0.90
21.60
32.60
7.50
20.7
31.7
6.6
23.10
51.30
54.40
38.70
28.2
31.3
15.6
44.20
52.60
55.70
53.40
8.4
11.5
9.2
2.00
56.90
57.00
28.80
54.9
55
26.8
32.80
49.60
10.10
32.8
49.6
10.1
32.80
49.60
10.10
32.8
49.6
10.1
16.20
24.40
5.00
16.2
24.4
5
4.00
51.30
54.40
26.40
47.3
50.4
22.4
4.60
55.50
55.60
29.80
50.9
51
25.2
2.60
49.30
52.40
23.80
46.7
49.8
21.2
32.80
49.60
10.10
32.8
49.6
10.1
32.80
49.60
10.10
32.8
49.6
22.9
25.6
10.1
2.30
2.30
2.30
2.3
2.3
2.3
0.90
52.90
53.00
25.70
52
52.1
24.8
3.00
49.30
52.40
24.10
46.3
49.4
21.1
5.40
15.80
4.80
15.40
10.4
-0.6
10
17.80
47.50
50.20
36.50
29.7
32.4
18.7
32.80
49.60
10.10
32.8
49.6
10.1
0.90
32.80
49.60
11.00
31.9
48.7
10.1
31.00
44.70
12.30
31
44.7
12.3
22.90
33.90
7.90
22.9
33.9
7.9
28.10
41.80
9.40
28.1
41.8
9.4
5.00
43.50
35.00
29.50
38.5
30
24.5
4.00
57.90
58.00
32.00
53.9
54
28
30.40
44.10
11.70
30.4
44.1
11.7
22.30
33.30
7.30
22.3
33.3
7.3
28.30
42.00
9.60
28.3
42
9.6
27.90
41.60
9.20
27.9
41.6
9.2
24.60
35.60
10.50
23.7
34.7
9.6
11.50
17.00
4.00
11.5
17
4
37.20
54.00
14.50
37.2
54
14.5
1.30
48.70
48.70
26.50
47.4
47.4
25.2
0.40
1.50
1.50
1.50
1.1
1.1
1.1
1.80
4.90
4.90
5.60
3.1
3.1
3.8
22.70
5.90
5.90
19.50
-16.8
-16.8
-3.2
-2.4
0.90
20.90
5.90
5.90
18.50
-15
-15
23.30
16.10
7.90
27.40
-7.2
-15.4
4.1
0.90
3.70
3.70
3.70
2.8
2.8
2.8
71.60
2.00
2.00
27.80
-69.6
-69.6
-43.8
30.60
4.50
4.50
17.10
-26.1
-26.1
-13.5
67.40
36.90
11.90
70.90
-30.5
-55.5
3.5
0.60
2.80
2.80
2.80
2.2
2.2
2.2
22.20
13.40
5.20
24.70
-8.8
-17
2.5
1.60
5.10
5.10
5.10
3.5
3.5
3.5
1.00
3.30
3.30
3.30
2.3
2.3
2.3
1.70
5.30
5.30
5.30
3.6
3.6
3.6
2.00
14.30
8.80
13.10
12.3
6.8
11.1
0.60
2.80
2.80
2.80
2.2
2.2
2.2
1.00
5.00
5.00
5.00
4
4
4
0.40
2.20
2.20
2.20
1.8
1.8
1.8
20.50
4.00
4.00
16.60
-16.5
-16.5
-3.9
0.80
3.90
3.90
3.90
3.1
3.1
3.1
0.90
4.50
4.50
4.50
3.6
3.6
3.6
0.70
3.30
3.30
3.30
2.6
2.6
2.6
31.50
24.30
10.60
38.90
-7.2
-20.9
7.4
16.70
-26
-26
-9.3
3.30
3.30
3.30
2.6
2.6
2.6
12.60
-19.5
-19.5
-6.9
-13.8
26.00
0.70
19.50
39.60
25.80
-39.6
-39.6
21.20
2.30
2.30
16.20
-18.9
-18.9
-5
23.70
13.70
8.20
26.60
-10
-15.5
2.9
21.80
16.30
21.80
22.70
-5.5
0
24.00
19.70
11.50
31.00
-4.3
-12.5
7
53.10
47.00
33.30
65.60
-6.1
-19.8
12.5
68.50
43.20
18.20
77.20
-25.3
-50.3
8.7
12.60
-19.5
-19.5
-6.9
20.70
0.40
0.40
13.80
-20.3
-20.3
-6.9
0.40
2.20
2.20
2.20
1.8
1.8
1.8
1.50
5.20
5.20
5.20
3.7
3.7
3.7
1.00
5.00
5.00
5.00
4
4
4
1.70
6.30
6.30
6.30
4.6
4.6
4.6
19.50
0.9
0.70
3.30
3.30
3.30
2.6
2.6
2.6
6.60
25.80
9.30
23.40
19.2
2.7
16.8
0.70
3.40
3.40
3.40
2.7
2.7
2.7
12.60
-19.5
-19.5
-6.9
1.00
5.00
5.00
5.00
4
4
4
0.70
3.40
3.40
3.40
2.7
2.7
2.7
1.00
2.80
2.80
3.20
1.8
1.8
2.2
0.70
3.40
3.40
3.40
2.7
2.7
2.7
0.80
1.60
1.60
1.60
0.8
0.8
0.8
1.00
2.00
2.00
2.00
1
1
1
0.90
21.60
32.60
7.50
20.7
31.7
6.6
0.60
2.80
2.80
19.50
32.50
2.80
2.2
2.2
2.2
20.90
-32.5
-32.5
-11.6
Common Name
Loggerhead Shrike
European Starling
Cassin's Vireo
Hutton's Vireo
Warbling Vireo
Orange-Crowned Warbler
Yellow Warbler
Yellow-Rumped Warbler
Black-Throated Gray Warbler
Townsend's Warbler
Macgillivray's Warbler
Common Yellowthroat
Wilson's Warbler
Yellow-Breasted Chat
Western Tanager
Black-Headed Grosbeak
Lazuli Bunting
Spotted Towhee
Lark Sparrow
Savannah Sparrow
Grasshopper Sparrow
Song Sparrow
Lincoln's Sparrow
Golden-Crowned Sparrow
White-Crowned Sparrow
Dark-Eyed Junco
Red-Winged Blackbird
Tricolored Blackbird
Western Meadowlark
Yellow-Headed Blackbird
Brewer's Blackbird
Brown-Headed Cowbird
Bullock's Oriole
House Finch
Pine Siskin
Lesser Goldfinch
American Goldfinch
Virginia Opossum
Vagrant Shrew
Coast Mole
Broad-Footed Mole
Little Brown Myotis
Yuma Myotis
Long-Eared Myotis
Fringed Myotis
Long-Legged Myotis
California Myotis
Silver-Haired Bat
Big Brown Bat
Hoary Bat
Townsend's Big-Eared Bat
Brush Rabbit
Black-Tailed Jackrabbit
Botta's Pocket Gopher
Western Harvest Mouse
Deer Mouse
Dusky-Footed Woodrat
California Vole
Norway Rat
House Mouse
Pacific Jumping Mouse
Common Porcupine
Coyote
Gray Fox
Black Bear
Ringtail
Raccoon
Long-Tailed Weasel
American Mink
Striped Skunk
Northern River Otter
Bobcat
Harbor Seal
Elk
Mule Deer
Western Pond Turtle
Western Fence Lizard
Western Skink
Southern Alligator Lizard
Common Garter Snake
Western Terrestrial Garter Snake
Pacific Coast Aquatic Garter Snake
Current
Condition
Alternative 4 muted (2.0 ft)
Alternative 4 full (2.8 ft)
Green & Gold
Current to Current to
Alt. 4 muted Alt. 4 full
Current to
G&G
0.70
1.30
1.30
1.30
0.6
0.6
0.6
3.30
7.20
7.20
8.20
3.9
3.9
4.9
0.70
3.30
3.30
3.30
2.6
2.6
2.6
0.90
4.50
4.50
4.50
3.6
3.6
3.6
1.00
5.00
5.00
5.00
4
4
4
1.70
6.30
6.30
6.30
4.6
4.6
4.6
1.00
5.00
5.00
5.00
4
4
4
13.60
3.40
3.40
11.70
-10.2
-10.2
-1.9
0.60
2.80
2.80
2.80
2.2
2.2
2.2
0.40
2.20
2.20
2.20
1.8
1.8
1.8
0.70
3.30
3.30
3.30
2.6
2.6
2.6
60.10
39.30
14.30
68.00
-20.8
-45.8
7.9
1.30
5.40
5.40
5.40
4.1
4.1
4.1
0.70
3.30
3.30
3.30
2.6
2.6
2.6
0.40
2.20
2.20
2.20
1.8
1.8
1.8
1.00
5.00
5.00
5.00
4
4
4
1.40
5.90
5.90
5.90
4.5
4.5
4.5
1.40
4.60
4.60
4.60
3.2
3.2
3.2
60.00
2.00
2.00
40.00
-58
-58
-20
56.60
37.10
12.10
50.00
-19.5
-44.5
-6.6
37.50
-58.5
-58.5
-21
30.20
25.6
6.4
22.1
58.50
8.10
33.70
14.50
17.50
-27.3
-27.3
-9.8
0.40
0.90
0.90
0.90
0.5
0.5
0.5
0.60
1.10
1.10
1.10
0.5
0.5
0.5
0.70
3.30
3.30
3.30
2.6
2.6
2.6
65.70
17.20
9.00
55.30
-48.5
-56.7
-10.4
17.20
2.80
2.80
13.80
-14.4
-14.4
-3.4
59.70
1.30
1.30
39.30
-58.4
-58.4
-20.4
2.70
-10.5
-10.5
-7.8
-22.9
-22.9
-22.9
27.30
10.50
22.90
37.30
4.10
4.10
27.90
-33.2
-33.2
-9.4
0.40
2.20
2.20
2.20
1.8
1.8
1.8
1.30
4.40
4.40
4.40
3.1
3.1
3.1
13.20
1.70
1.70
10.00
-11.5
-11.5
-3.2
14.00
3.50
3.50
11.80
-10.5
-10.5
-2.2
13.80
3.70
3.70
12.00
-10.1
-10.1
-1.8
4.60
6.30
6.30
8.60
1.7
1.7
4
65.00
30.80
14.30
65.20
-34.2
-50.7
0.2
25.10
-38.9
-38.9
-13.8
5.00
5.00
43.00
-86
-86
-48
1.50
1.50
1.50
1.5
1.5
1.5
20.30
2.40
2.40
10.70
-17.9
-17.9
-9.6
1.20
6.90
6.90
6.90
5.7
5.7
5.7
0.30
1.70
1.70
1.70
1.4
1.4
1.4
0.70
3.30
3.30
3.30
2.6
2.6
2.6
8.20
4.60
4.60
4.60
-3.6
-3.6
-3.6
38.90
91.00
7.50
3.30
3.30
3.30
-4.2
-4.2
-4.2
29.00
6.30
6.30
19.70
-22.7
-22.7
-9.3
0.70
3.30
3.30
3.30
2.6
2.6
2.6
0.20
0.40
0.40
0.40
0.2
0.2
0.2
70.10
1.50
1.50
30.70
-68.6
-68.6
-39.4
57.00
1.50
1.50
22.20
-55.5
-55.5
-34.8
90.70
1.30
1.30
39.30
-89.4
-89.4
-51.4
66.40
29.10
12.60
51.60
-37.3
-53.8
-14.8
27.20
28.40
11.90
25.80
1.2
-15.3
-1.4
0.70
3.30
3.30
3.30
2.6
2.6
2.6
84.20
25.10
8.60
59.20
-59.1
-75.6
-25
21.20
3.30
3.30
3.30
-17.9
-17.9
-17.9
63.40
23.80
7.30
45.00
-39.6
-56.1
-18.4
60.40
5.00
5.00
30.10
-55.4
-55.4
-30.3
2.90
3.30
3.30
5.00
0.4
0.4
2.1
56.30
13.90
8.40
33.80
-42.4
-47.9
-22.5
53.50
4.40
4.40
26.50
-49.1
-49.1
30.50
3.90
3.90
16.50
-26.6
-26.6
-14
14.40
4.80
4.80
13.10
-9.6
-9.6
-1.3
10.50
14.10
5.90
13.30
3.6
-4.6
2.8
60.50
4.80
4.80
34.00
-55.7
-55.7
-26.5
-27
9.00
54.50
35.00
43.00
45.5
26
34
69.30
27.10
13.40
54.20
-42.2
-55.9
-15.1
5.00
41.50
38.70
29.10
36.5
33.7
24.1
30.80
20.20
9.20
35.10
-10.6
-21.6
4.3
34.40
51.20
11.70
34.4
51.2
11.7
54.20
4.40
4.40
32.60
-49.8
-49.8
-21.6
41.00
5.00
5.00
21.70
-36
-36
-19.3
6.00
10.90
10.90
14.20
4.9
4.9
8.2
2.00
7.00
7.00
7.00
5
5
5
40.60
6.30
6.30
31.40
-34.3
-34.3
-9.2
40.60
6.30
6.30
31.40
-34.3
-34.3
-9.2
65.40
8.10
8.10
37.20
-57.3
-57.3
-28.2
8.30
10.10
10.10
15.40
1.8
1.8
7.1
6.60
10.80
10.80
14.80
4.2
4.2
8.2
Table 10. Mean habitat change of vertebrate classes and guilds and number of species positively and negatively affected by the
conversion of MSPA to each of three management scenarios as modeled by CWHR.
Vertebrate classes & guilds
All amphibians
All reptiles
Aquatic
Terrestrial
mean positive/ no
change
change
-28.48
-15.71
-24.0
4
-15.5
6
negative
3
4
mean positive/ no
change
change
negative
-28.48
-15.71
-24.0
4
3
-15.5
6
4
mean
change
-11.33
-2.59
-7.3
-4.1
positive/ no
change
negative
4
6
3
4
All birds
Waterfowl
Waterbirds
Raptors
Shorebirds
Songbirds/Allies
Upland birds
3.6
-0.4
19.3
-19.5
35.9
-6.2
-12.1
16
32
4
28
48
2
14
3
18
0
31
1
4.0
2.9
20.6
-23.7
42.4
-8.2
-12.1
17
31
4
27
49
2
13
4
18
1
30
1
4.4
4.2
11.5
-5.6
15.9
0.2
-2.1
21
33
10
28
56
2
9
2
12
0
23
1
All mammals
Bats
Insectivores
Small rodents
Large rodents
Ungulates
Carnivores
Marine mammals
-21.4
-3.4
-53.0
-36.9
-41.2
-42.9
-13.5
34.4
6
0
2
1
0
4
1
4
3
6
2
2
7
0
-24.7
-3.4
-58.5
-45.1
-41.2
-42.9
-19.1
51.2
6
0
1
1
0
3
1
4
3
7
2
2
8
0
-9.7
-1.3
-20.5
-19.6
-24.0
-20.5
-3.4
11.7
6
1
1
1
0
5
1
4
2
7
2
2
6
0
Figure 1. Map of “Alternative 4” habitat management scenario available online from the City of Arcata. The wide bayside levee breach depicted in this figure would likely result in a relatively unrestricted tidal flow, which we modeled as a
“full tidal flow.” We also modeled Alternative 4 with a narrow breach and a “muted” tidal flow. See Figs. 6 and 7 for
predicted vegetation resulting from the muted and full flow scenarios, respectively.
Shrubs & trees
Alnus rubra
Baccharis pilularis
Picea sitchensis
Rubus discolor
Rubus ursinus
Salix spp.
Sambucus sp.
Malus sylvestris
Boundary for shrub data
CWHR habitat types
Coastal scrub dike/levee
Salt marsh - low
Salt marsh -mid
Pasture
Perennial grassland
Salt marsh
Buildings/urban elements
Riparian/mixed woodland
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200
0
200
400 Meters
W
E
S
Figure 2. Current vegetation in the MSPA in terms of habitat types recognized by the California Wildlife Habitat
Relationships System. Also depicted are significant shrubs and trees, which we mapped with hand-held GPS receivers within
the yellow outlined area.
Spot elevation in feet above MSL
2.82 ft
2.82 ft
2.82 ft
3.11 ft
N
100
0
100
200 Meters
Figure 3. Low tide aerial photo (1997) of the existing salt marsh on the bay-side levees currently of the McDaniel
Slough Project Area (MSPA). The elevations of 3 points along the edge of the salt marsh and one point slightly inside
the salt marsh are shown. Although the sample size is very small, the salt marsh edge is consistently at 2.82 ft mean
sea level (MSL).
“Green & Gold”
Habitat management scenario
Remove eco-levee
Add flood
levee
Remove flood
levee
Narrow dike breach
Figure 4. Diagram of the “Green & Gold” habitat management scenario based on the map available online from the City of
Arcata for “Alternative 4.” Changes relative to Alternative 4 are shown in yellow font. This management scenario is intended to
mitigate the loss of perennial grassland by retaining some of it behind the levee bisecting the project area. See Fig. 8 for
predicted vegetation resulting from this scenario.
#
Jacoby creek salt marsh
Salt marsh survey transect
Grassland survey area
Pasture survey area
Slough survey transect
Riparian survey transect
Levee survey transect
Raptor survey point
Project Boundary
N
#
N
100
0
100 200 300 400 Meters
100
a)
0
100
200 Meters
b)
Figure 5. Locations of wildlife survey areas, transects, and points for the (a) McDaniel Slough Project Area and (b) Jacoby
Creek salt marsh. All surveys conducted in March, 2002.
Alternative 4 - muted flow (2.0 feet)
Tidal mudflat
Salt marsh low - Salicornia
Salt marsh mid - Spartina
Salt marsh high - mixed
Coastal scrub - dike/levee
Freshwater lake/marsh
Brackish lake
Riparian/mixed woodland
N
300
0
300
600 Meters
Figure 6. Predicted vegetation following the Alternative 4 – muted tidal flow habitat management scenario in which salt
marsh is modeled to grow to a lower elevational threshold of 2.0 feet mean sea level.
Alternative 4 - full flow (2.8 feet)
Tidal mudflat
Salt marsh low - Salicornia
Salt marsh mid - Spartina
Salt marsh high - mixed
Coastal scrub - dike/levee
Freshwater lake/marsh
Brackish lake
Riparian/mixed woodland
N
300
0
300
600 Meters
Figure 7. Predicted vegetation following the Alternative 4 – full tidal flow habitat management scenario in which salt
marsh is modeled to grow to a lower elevational threshold of 2.8 feet mean sea level.
"Green & Gold option"
Tidal mudflat
Salt marsh low - Salicornia
Salt marsh mid - Spartina
Salt marsh high - mixed
Coastal scrub dike/levee
Freshwater lake/marsh
Brackish lake
Riparian/mixed woodland
Perennial grassland
Slough
N
300
0
300
600 Meters
Figure 8. Predicted vegetation following the “Green & Gold” habitat management scenario in which a levee retains
some perennial grassland and salt marsh is modeled to grow to a lower elevational threshold of 2.0 feet mean sea level
under a muted tidal flow.
45
Number of bird species
40
35
30
25
20
15
10
5
0
155
1548
MSPA
Salt Marsh (high tide)
77
Salt Marsh (low tide)
Figure 9. The number of bird species as adjusted by rarefaction in the MSPA and in the Jacoby Creek salt marsh at
high and low tides. Error bars indicate +/- 1 standard deviation resulting from rarefaction. White numerals indicate
the sample size (# of individual birds detected). No error bars exists for salt marsh at low tide because it had the
lowest sample size and was therefore not subsampled by rarefaction.
180
Number of species
160
175
Positively affected
Negatively affected
154
151
140
120
100
98
100
77
80
60
40
Current to Alt. 4-muted
Current to Alt. 4-full
Current to Green & Gold
Figure 10. The number of species predicted to be postively and negatived affect by the conversion of the MSPA to each
of three management scenarios according to modeling via CWHR. Chi-squared analyses indicated that the Green &
Gold scenario resulted in signifcantly different numbers of positive and negative species than both Alternative 4
management scnearios, which did not differ from each other (see text for details).
Appendix 1. Species mentioned in text, their scientific names, ecological guild, predicted occurrence in the McDaniel
Slough Project Area (based on its current condition using CWHR -- see text), and bird and mammal species
occurrence based on surveys conducted in March 2002 (see text).
Predicted
Presence
Observed
*
Presence
Ambystoma gracila
Hyla regilla
Ranas aurora
Rana boylei
Rana catesbeiana
Clemmys marmotata
Thamnophis atratus
X
na
X
na
X
na
X
na
X
na
X
na
X
na
Terrestrial Herptiles
Rough-Skinned Newt
A012 Ensatina
A014 California Slender Salamander
A032 Western Toad
A048 Pacific Giant Salamander
R022 Western Fence Lizard
R036 Western Skink
R040 Southern Alligator Lizard
R061 Common Garter Snake
R062 Western Terrestrial Garter Snake
Taricha granulosa
Ensatina eschscholtzi
Batrachoseps attenuatus
Bufo boreas
Dicamptodon ensatus
Sceloporus occidentalis
Eumeces skiltonianus
Gerrhonotus multicarinutus
Thamnophis sirtalis
Thamnophis elegans
X
na
X
na
X
na
X
na
X
na
X
na
X
na
X
na
X
na
X
na
A010 Del Norte Salamander
Plethodon elongatus
CCommon Name
Aquatic Herptiles
A002 Northwestern Salamander
A039 Pacific Tree Frog
A040 Red-Legged Frog
A043 Foothill Yellow-Legged Frog
A046 Bullfrog
R004 Western Pond Turtle
R078 Pacific Coast Aquatic Garter Snake
A006
Scientific name
A020 Black Salamander
Aneides flavipunctatus
A021 Clouded Salamander
Aneides ferreus
R048 Ringneck Snake
Diadophis punctatus
R049 Sharp-Tailed Snake
Contia tenuis
R051 Racer
Coluber constrictor
R053 Striped Racer
Masticophis lateralis
R057 Gopher Snake
Pituophis melanoleucus
R058 Common Kingsnake
Lampropeltis getulus
R059 California Mountain Kingsnake
Lampropeltis zonata
R076 Western Rattlesnake
Crotalis viridis
Waterbirds
Red-Throated Loon
B003 Common Loon
B006 Pied-Billed Grebe
B007 Horned Grebe
B008 Red-Necked Grebe
B009 Eared Grebe
B010 Western Grebe
B043 Brown Pelican
B044 Double-Crested Cormorant
B046 Brandt's Cormorant
B049 American Bittern
B051 Great Blue Heron
B052 Great Egret
B053 Snowy Egret
B057 Cattle Egret
B058 Green Heron
B059 Black-Crowned Night Heron
B062 White-Faced Ibis
B145 Virginia Rail
B146 Sora
B149 American Coot
B211 Bonaparte's Gull
Gavia stellata
Gavia immer
Podilymbus podiceps
Podiceps auritus
Podiceps grisegena
Podiceps nigricollis
Aechmophorus occidentalis
Pelecanus occidentalis
Phalacrocorax auritus
Phalacrocorax penicillatus
Botarus lentiginosus
Ardea herodias
Ardea alba
Egretta thula
Bubulcus ibis
Butorides virescens
Nycticorax nycticorax
Plegadis chihi
Rallus limicola
Porzana carolina
Fulica americana
Larus philadelphia
B001
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CCommon Name
B212 Heermann's Gull
B213 Mew Gull
B214 Ring-Billed Gull
B215 California Gull
B216 Herring Gull
B217 Thayer's Gull
B220 Western Gull
B221 Glaucous-Winged Gull
B227 Caspian Tern
B229 Elegant Tern
B231 Common Tern
B233 Forster's Tern
Scientific name
Larus heermanni
Larus canus
Larus delawarensis
Larus californicus
Larus argentatus
Larus thayeri
Larus occidentalis
Larus glaucescens
Sterna caspia
Sterna elegans
Sterna hirundo
Sterna forsteri
B042 American White Pelican
Pelecanus erythrorhynchos
B235 Black Tern
Chlidonias niger
B247 Rhinoceros Auklet
Cerorhina monocerata
Waterfowl
Tundra Swan
B070 Greater White-Fronted Goose
B071 Snow Goose
B072 Ross' Goose
B074 Brant
B075 Canada Goose
B076 Wood Duck
B077 Green-Winged Teal
B079 Mallard
B080 Northern Pintail
B082 Blue-Winged Teal
B083 Cinnamon Teal
B084 Northern Shoveler
B085 Gadwall
B086 Eurasian Wigeon
B087 American Wigeon
B089 Canvasback
B090 Redhead
B091 Ring-Necked Duck
B093 Greater Scaup
B094 Lesser Scaup
B097 Long-Tailed Duck
B099 Surf Scoter
B100 White-Winged Scoter
B101 Common Goldeneye
B103 Bufflehead
B104 Hooded Merganser
B105 Common Merganser
B106 Red-Breasted Merganser
B107 Ruddy Duck
Cygnus columbianus
Anser albifrons
Chen caerulescens
Chen rossii
Branta bernicla
Branta canadensis
Aix sponsa
Anas crecca
Anas platyrhynchos
Anas acuta
Anas discors
Anas cyanoptera
Anas clypeata
Anas strepera
Anas penelope
Anas americana
Aythya valisineria
Aythya americana
Aythya collaris
Aythya marila
Aythya affinis
Clangula hyemalis
Melanitta perspicillata
Melanitta fusca
Bucephala clangula
Bucephala albeola
Lophodytes cucullatus
Mergus merganser
Mergus serrator
Oxyura jamaicensis
B098 Black Scoter
Melanitta nigra
B102 Barrow's Goldeneye
Bucephala islandica
Raptors
Turkey Vulture
B110 Osprey
B111 White-Tailed Kite
B113 Bald Eagle
B114 Northern Harrier
B115 Sharp-Shinned Hawk
B116 Cooper's Hawk
B119 Red-Shouldered Hawk
B123 Red-Tailed Hawk
B124 Ferruginous Hawk
B125 Rough-Legged Hawk
B127 American Kestrel
B128 Merlin
Peregrine Falcon
B131 Prairie Falcon
Cathartes aura
Pandion haliaetus
Elanus leucurus
Haliaeetus leucocephalus
Circus cyaneus
Accipiter striatus
Accipiter cooperii
Buteo lineatus
Buteo jamaicensis
Buteo regalis
Buteo lagopus
Falco sparverius
Falco columbarius
Falco peregrinus
Falco mexicanus
B067
B108
Predicted
Presence
Observed
Presence *
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CCommon Name
B262 Barn Owl
B264 Western Screech Owl
B265 Great Horned Owl
B267 Northern Pygmy Owl
B269 Burrowing Owl
B272 Long-Eared Owl
B273 Short-Eared Owl
B274 Northern Saw-Whet Owl
Scientific name
Tyto alba
Otus kennicottii
Bubo virginianus
Glaucidium gnoma
Athene cunicularia
Asio otus
Asio flammeus
Aegolius acadicus
B117 Northern Goshawk
Accipiter gentilis
B126 Golden Eagle
Aquila chrysaetos
Shorebirds
Black-Bellied Plover
B156 Semipalmated Plover
B158 Killdeer
B163 Black-Necked Stilt
B164 American Avocet
B165 Greater Yellowlegs
B166 Lesser Yellowlegs
B168 Willet
B170 Spotted Sandpiper
B172 Whimbrel
B173 Long-Billed Curlew
B176 Marbled Godwit
B177 Ruddy Turnstone
B178 Black Turnstone
B180 Red Knot
B183 Western Sandpiper
B185 Least Sandpiper
B191 Dunlin
B193 Stilt Sandpiper
B196 Short-Billed Dowitcher
B197 Long-Billed Dowitcher
B199 Common Snipe
B200 Wilson's Phalarope
B629 Pacific Golden-Plover
B648 Baird's Sandpiper
B649 Pectoral Sandpiper
B655 Red-Necked Phalarope
B656 Red Phalarope
Pluvialis squatarola
Charadrius semipalmatus
Charadrius vociferus
Himantopus mexicanus
Recurvirostra americana
Tringa melanoleuca
Tringa flavipes
Catoptrophorus semipalmatus
Actitis macularia
Numenius phaeopus
Numenius americanus
Limosa fedoa
Arenaria interpres
Arenaria melanocephala
Calidris canutus
Calidris mauri
Calidris minutilla
Calidris alpina
Calidris himantopus
Limnodromus griesus
Limnodromus scolopaceus
Gallinago gallinago
Phalaropus tricolor
Pluvialis fulva
Calidris bairdii
Calidris melanotos
Phalaropus lobatus
Phalaropus fulicaria
B154 Snowy Plover
Charadrius alexandrinus
Upland Gamebirds
California Quail
B251 Band-Tailed Pigeon
B255 Mourning Dove
Callipepla californica
Columba fasciata
Zenaida macroura
B133 Ring-Necked Pheasant
Phasianus colchicus
B136 Ruffed Grouse
Bonasa umbellus
B151
B140
B138 Wild Turkey
Meleagris gallopavo
B141 Mountain Quail
Oreortyx pictus
B260 Greater Roadrunner
Geococcyx californianus
Songbirds & Allies
Common Nighthawk
B287 Anna's Hummingbird
B291 Rufous Hummingbird
B292 Allen's Hummingbird
B293 Belted Kingfisher
B299 Red-Breasted Sapsucker
B303 Downy Woodpecker
B304 Hairy Woodpecker
B307 Northern Flicker
B311 Western Wood-Pewee
B315 Willow Flycatcher
B320 Pacific-Slope Flycatcher
Chordeiles minor
Calypte anna
Selasphorus rufus
Selasphorus sasin
Ceryle alcyon
Sphyrapicus ruber
Picoides pubescens
Picoides villosus
Colaptes auratus
Contopus sordidulus
Empidonax trailii
Empidonax difficilis
B276
Predicted
Presence
Observed
Presence *
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CCommon Name
B321 Black Phoebe
B323 Say's Phoebe
B326 Ash-Throated Flycatcher
B333 Western Kingbird
B337 Horned Lark
B338 Purple Martin
B339 Tree Swallow
B340 Violet-Green Swallow
B341 Northern Rough-Winged Swallow
B343 Cliff Swallow
B344 Barn Swallow
B353 American Crow
B354 Common Raven
Black-Capped Chickadee
B357 Chestnut-Backed Chickadee
B360 Bushtit
B368 Bewick's Wren
B369 House Wren
B370 Winter Wren
B372 Marsh Wren
B376 Ruby-Crowned Kinglet
B380 Western Bluebird
B385 Swainson's Thrush
B386 Hermit Thrush
B389 American Robin
B390 Varied Thrush
B391 Wrentit
B393 Northern Mockingbird
B404 American Pipit
B407 Cedar Waxwing
B409 Northern Shrike
B410 Loggerhead Shrike
B411 European Starling
B415 Cassin's Vireo
B417 Hutton's Vireo
B418 Warbling Vireo
B425 Orange-Crowned Warbler
B430 Yellow Warbler
B435 Yellow-Rumped Warbler
B436 Black-Throated Gray Warbler
B437 Townsend's Warbler
B460 Macgillivray's Warbler
B461 Common Yellowthroat
B463 Wilson's Warbler
B467 Yellow-Breasted Chat
B471 Western Tanager
B475 Black-Headed Grosbeak
B477 Lazuli Bunting
B483 Spotted Towhee
B495 Lark Sparrow
B499 Savannah Sparrow
B501 Grasshopper Sparrow
B505 Song Sparrow
B506 Lincoln's Sparrow
Nelson's Sharp-Tailed Sparrow
Fox Sparrow
White-Throated Sparrow
Swamp Sparrow
B509 Golden-Crowned Sparrow
B510 White-Crowned Sparrow
B512 Dark-Eyed Junco
B519 Red-Winged Blackbird
B520 Tricolored Blackbird
B521 Western Meadowlark
B522 Yellow-Headed Blackbird
Scientific name
Sayornis nigricans
Sayornis saya
Myiarchus cinerascens
Tyrannus verticalis
Eremophila alpestris
Progne subis
Tachycineta bicolor
Tachycineta thalassina
Stelgidopteryx serripennis
Petrochelidon fulva
Hirundo rustica
Corvus brachyrhynchos
Corvus corax
Poecile atricapilla
Poecile rufescens
Psaltriparus minimus
Thryomanes bewickii
Troglodytes aedon
Troglodytes troglodytes
Cistothorus palustris
Regulus calendula
Sialia mexicana
Catharus ustulatus
Catharus guttatus
Turdus migratorius
Ixoreus naevius
Chamaea fasciata
Mimus polyglottos
Anthus rubescens
Bombycilla cedrorum
Lanius excubitor
Lanius ludovicianus
Sturna vulgaris
Vireo cassinii
Vireo huttoni
Vireo gilvus
Vermivora celata
Dendoica petechia
Dendroica coronata
Dendroica nigrescens
Dendroica townsendi
Oporornis tolmiei
Geothlypis trichas
Wilsonia pusilla
Icteria virens
Piranga ludoviciana
Pheucticus melanocephalus
Passerina amoena
Pipilo maculatus
Chondestes grammacus
Passerculus sandwichensis
Ammodramus savannarum
Melospiza melodia
Melospiza lincolnii
Ammodramus nelsoni
Passerella iliaca
Zonotrichia albicollis
Melospiza georgiana
Zonotrichia atricapilla
Zonotrichia leucophrys
Junco hyemalis
Agelaius phoeniceus
Agelaius tricolor
Sturnella neglecta
Xanthocephalus xanthocephalus
Predicted
Presence
Observed
Presence *
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
CCommon Name
B524 Brewer's Blackbird
B528 Brown-Headed Cowbird
B532 Bullock's Oriole
B538 House Finch
B542 Pine Siskin
B543 Lesser Goldfinch
B545 American Goldfinch
B548 Clark's Grebe
Scientific name
Euphagus cyanocephalus
Molothrus ater
Icterus galbula
Carpodacus mexicanus
Carduelis pinus
Carduelis psaltria
Carduelis tristis
Phalacrocorax auritus
B277 Common Poorwill
Phalaenoptilus nuttalii
B294 Lewis' Woodpecker
Melanerpes lewis
B302 Nuttall's Woodpecker
Picoides nuttallii
B346 Steller's Jay
Cyanocitta stelleri
B348 Western Scrub-Jay
Aphelocoma californica
B358 Oak Titmouse
Baeolophus inornatus
B362 White-Breasted Nuthatch
Sitta carolinensis
B367 Canyon Wren
Catherpes mexicanus
B377 Blue-Gray Gnatcatcher
Polioptila caerulea
B381 Mountain Bluebird
Siala currucoides
B398 California Thrasher
Toxostoma redivivum
B484 California Towhee
Pipilo crissalis
B554 Plumbeous Vireo
Vireo plumbeus
B702 Chimney Swift
Chaetura vauxi
Predicted
Presence
Observed
Presence *
X
X
X
X
X
X
X
X
X
X
X
X
Bats
M021 Little
Brown Myotis
Myotis
M025 Long-Eared Myotis
M026 Fringed Myotis
M027 Long-Legged Myotis
M028 California Myotis
M030 Silver-Haired Bat
M032 Big Brown Bat
M034 Hoary Bat
M037 Townsend's Big-Eared Bat
Myotis lucifugus
Myotis yumanensis
Myotis evotis
Myotis thysanodes
Myotis volans
Myotis californicus
Lasionycteris noctivagans
Eptesicus fuscus
Lasiurus cinereus
Plecotus townsendii
M038 Pallid Bat
Antrozous pallidus
Insectivores
Shrew
M017 Coast Mole
M018 Broad-Footed Mole
Sorex vagrans
Scapanus orarius
Scapanus latimanus
M005 Fog Shrew
Sorex sonomae
M023 Yuma
M003 Vagrant
M011 Marsh Shrew
Sorex bendirii
M015 Shrew-Mole
Neutrichus gibbsii
M016 Townsend's Mole
Scapanus townsendii
Small Rodents
Pocket Gopher
M113 Western Harvest Mouse
M117 Deer Mouse
M127 Dusky-Footed Woodrat
M134 California Vole
M141 Norway Rat
M142 House Mouse
M144 Pacific Jumping Mouse
Thomomys bottae
Reithyrodontomys megalotis
Peromyscus maniculatus
Neotoma fuscipes
Microtus californicus
Rattus norvegicus
Mus musculus
Zapus trinotatus
M072 California Ground Squirrel
Spermophilus beecheyi
M075 Golden-Mantled Ground Squirrel
Spermophilus lateralis
M080 Northern Flying Squirrel
Glaucomys sabrinus
M081 Botta's
M119 Brush Mouse
Peromyscus boylii
M120 Pinon Mouse
Peromyscus truei
M128 Bushy-Tailed Woodrat
Neotoma cinerea
M135 Townsend's Vole
Microtus townsendii
M136 Long-Tailed Vole
Microtus longicaudus
M137 Creeping Vole
Microtus oregoni
M143 Western Jumping Mouse
Zapus princeps
X
X
X
X
X
X
X
X
X
X
D
X
X
X
X
D
X
D
X
X
X
X
X
D
CCommon Name
Large Rodents & Allies
M045 Brush Rabbit
M051 Black-Tailed Jackrabbit
M145 Common Porcupine
Scientific name
M052 Mountain Beaver
Aplodontia rufa
M112 American Beaver
Castor canadensis
M139 Common Muskrat
Ondatra zibethicus
Carnivores
Opossum
M146 Coyote
M149 Gray Fox
M151 Black Bear
M152 Ringtail
M153 Raccoon
M157 Long-Tailed Weasel
M158 American Mink
M162 Striped Skunk
M163 Northern River Otter
M166 Bobcat
Didelphis virginiana
Canis latrans
Urocyon cinereoargenteus
Urus americanus
Bassariscus astutus
Procyon lotor
Mustela frenata
Mustela vison
Mephitus mephitus
Lontra canadensis
Felis rufus
M154 American Marten
Martes americana
M001 Virginia
Sylvilagus bachmani
Lepus californicus
Erethizon dorsatum
M156 Ermine
Mustela erminea
M160 American Badger
Taxidea taxus
M165 Mountain Lion
Felis concolor
Predicted
Presence
Observed
Presence *
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Hooved Mammals
M177 Elk
M181 Mule
Deer
Cervus elaphus
Odocoileus hemionus
M176 Wild Pig
Sus scrofa
M186 Feral Goat
Capra hircus
Marine Mammals
Seal
M171 Harbor
X
X
Phoca vitulina
* X indicates the species was observed in March 2002, "D" indicates documented occurrence based on Dunk (1992)
Appendix 2.
Salt marsh vegetation types
High elevation
Mid-elevation
Low elevation
Appendix 3.
Appendix 4. Plants and CWHR habitats identified within the project area. Wetland ratings are given in the last column.
Habitats: CSC= coastal scrub, FEW= fresh emergent wetland, PAS= pasture, PGS= perennial grassland,
SEW= saline emergent wetland, VRI= valley riparian. Wetland rating for plant species- UPL (99% Upland),
FACU (facultative upland, 1<33% probability of occurring in wetlands), FAC- (less facultative),
FAC (facultative plants, 33-67% probability of occurring in wetland), FAC+ (more facultative),
FACW (Facultative wetland, 67-99% probability of occurring in wetlands), OBL (obligative wetland species,
>99% occurring in wetlands). Some plants are coded ad NI or Not Indicative or are not rated.
Wetland indicator species are in blue.
PLANT
Ferns
Sword fern
Trees/shrubs
Sitka spruce
Red Alder
Apple
Himalaya blackberry
California balckberry
Coyote bush
Willow
Elderberry
Grasses
Brome
Sedge
Hairgrass
Saltgrass
Fescue
Velvet grass
Rush
Soft sedge
Blue grass
Saltmarsh bullrush
Chilean cordgrass
Bullrush
Herbs/Forbs
Yarrow
Angelica
Calif Aster
Black mustard
Humboldt Bay owl's clover
Chickweed
Bull thistle
Miner's lettuce
Poison Hemlock
Queen Anne's Lace
Teasel
Fennel
Bedstraw
Marsh pennywort
Duckweed
Lupine
Clover
Water parsley
Plantain
Silver cinquefoil
Buttercup
Wild radish
Water cress
Dock spp.
Sheep sorrel
Pickleweed
Vetch
Scientific name
Habitat
Wetland rating
Polystichum munitum
CSC, PGS
FACU
Picea sitchensis
Alnus rubra
Malus sylvestris
Rubus discolor
Rubus ursinus
Baccharis pilularis
Salix spp.
Sambucus spp
CSC
CSC, VRI
CSC
CSC, PGS, VRI
CSC, PGS, VRI
CSC, PGS, VRI
CSC, PGS, VRI
PSG
NI
FACW
NI
FACW
FAC+
UPL
FACW
FACU
Bromus spp.
Carex spp.
Deschampsia ceaspitosa
Distichilis spicata
Festuca spp
Holcus lanatus
Juncus spp.
Juncus effusus
Poa pratensis
Scirpus robustus
Spartina densiflora
Typha latifolia
CSC
FEW, PGS
FEW, PGS
FEW, SEW
CSC, FEW, PGS, VRI
CSC, FEW, PGS, VRI
CSC, FEW, PGS, VRI
FEW
PGS
FEW
FEW, SEW
FEW, PGS
OBL
FACW
FACW
FACFAC
FACW
OBL
FACW
OBL
OBL
OBL
Achillea millefolium
Angelica hendersoni
Aster chilensis
Brassica nigra
Castilleja ambigua humboldtensis
Cerastrium arvense
Cirsium vulgare
Claytonia perfoliata
Conium maculatum
Daucus carota
Dipsacus sylvestris
Foeniculum vulgare
Galium aparine
Hydrocotyle ranunculoides
Lemna spp
Lupinus spp.
Medicagp arabica
Oenanthe sarmentosa
Plantago spp.
Potentilla anserina
Ranunculus spp
Raphanus sativa
Rorippa nasturtium-aquaticum
Rumex spp.
Rumex acetosella
Salicornia virginica
Vicia spp.
CSC, PGS, VRI
PGS
CSC, PGS
CSC, PGS
SEW
PGS
PAS, PGS
CSC, PGS
PGS
CSC, PGS
CSC, PGS
CSC
CSC, PGS
FEW
FEW
CSC
PAS, PGS
CSC, FEW, PGS
CSC, FEW, PGS
CSC, FEW, PGS
PGS
PGS
FEW
CSC, FEW, PGS
CSC, FEW, PGS
FEW, PGS, SEW
PGS
FACU
NI
FACU
NI
FAC
FAC
FACU
FACU
FACW
UPL
NI
FACFACU
OBL
OBL
UPL
OBL
FACOBL
UPL
OBL
FACFACOBL
FACU