Land Cover Classification and Natural Resource Inventory
City of Minnetrista
Hennepin County, Minnesota
Prepared By:
Jason J. Husveth, Ecologist
Critical Connections, Inc.
163 North Victoria Street
Saint Paul, Minnesota 55104
David W. Thill, Resource Specialist
Hennepin Conservation District
6900 Wedgwood Road, Suite 140
Maple Grove, Minnesota 55311
Table of Contents
BACKGROUND AND PURPOSE ………………………………………………...……………. 1
NATURAL RESOURCES OF MINNETRISTA (EXISTING DATA).……………………..… 1
Presettlement Vegetation …………………….…………………………………………………. 1
National Wetlands Inventory …….……………………………….…………………….………. 1
Hennepin County Soil Survey .…………….……………………….…………………………… 2
Minnesota County Biological Survey …………….…….……………………………….……… 2
LAND COVER CLASSIFICATION METHODOLOGY ………………….…………..……… 3
Minnesota Land Cover Classification Modifiers .….……………………..……………..…….. 3
NATURAL RESOURCE INVENTORY METHODOLOGY …….………….……….………. 6
Natural Community Assessment Ranking…………………………………..………….……… 6
Rare Species (Fall Surveys and Potential Species by Habitat Type).………..………....……... 6
LAND COVER CLASSIFICATION RESULTS ..…………………………......……….………. 9
NATURAL RESOURCE INVETORY RESULTS ….………………....……………………….. 11
RECOMMENDATIONS ……………………...………………………..………..….….………… 23
REFERENCES ……………………………………………………………..…………………….. 28
FIGURES ……………………………………………………………………………….. Appendix A
LAND COVER TABLES ….…………………………………………………………... Appendix B
MINNESOTA LAND COVER CLASSIFICATION METHODOLOGY ....……….. Appendix C
NATURAL COMMUNITY ASSESSMENT RANKING GUIUDELINES ...….…… Appendix D
LIST OF FIGURES:
(Appendix A)
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Project Location
Presettlement Vegetation
National Wetland Inventory
Hennepin County Soil Survey
Minnesota County Biological Survey
Level 1 Land Cover Classification
Level 3 Land Cover Classification
Natural Community Quality (MLCCS M_33x Modifier)
Natural Community Rankings (Modified Natural Heritage Ranking System)
Potential Greenway Corridors
Natural Community Remnants Considered for Future Rare Species Surveys
LIST OF TABLES:
(Appendix B)
Table 1.
Table 2.
Table 3.
Level 1 Land Cover Acreage
Level 3 Land Cover Acreage
Level 4/5 Land Cover Acreage
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 1 of 28
BACKGROUND AND PURPOSE:
Critical Connections, Inc. (CCI) was retained by the Hennepin Conservation District (HCD) to
conduct a land cover classification and natural resource assessment within the City of Minnetrista,
Hennepin County, Minnesota (Appendix A, Figure 1).
The purpose of this project was to classify land cover for the entire City of Minnetrista (19,805
acres) and to assess the relative ecological quality of the City’s remaining natural areas. The
Minnesota Land Cover Classification System (MLCCS) was used as the methodology for classifying
land cover within the city. The method used to assess natural community quality were based on field
assessment protocols developed by the Minnesota Department of Natural Resources Natural
Heritage and Non-game Research Program, and were slightly modified for use for a project at the
City scale (rather than a state wide scale). The land cover classification and natural resource
inventory were conducted between October and November of 2001, and the geographic information
system (GIS) database was developed in December 2001 and January 2002.
EXISTING DATA ON MINNETRISTA’S NATURAL RESOURCES:
Several existing sources of natural resource information were compiled and reviewed by the project
consultant, prior to conducting the detailed land cover classification and natural resource assessment
for the City of Minnetrista. These data resources included presettlement vegetation, biological
survey information for Hennepin County, wetland and water resource information, and the Hennepin
County soil survey. These data layers are described in detail in the following text:
Presettlement Vegetation
According to the original land survey notes (compiled in Minnesota between 1853 and 1856), the
presettlement vegetation of what is now western Hennepin County was comprised primarily of
maple-basswood forest (or “Big Woods”), with small inclusions of wet prairie and lakes. Occasional
tamarack bogs were also recorded within close proximity to the city (Appendix A, Figure 2). From
the original land survey notes, it is apparent that the City of Minnetrista was 5 to 10 miles west of a
major shift in predominant vegetation types; maple-basswood forest in western Hennepin County,
and oak openings and barrens and prairie in eastern Hennepin County (see figure 2). This shift in
vegetation is likely due to changes in mean annual precipitation, surficial geology, and soil types.
National Wetlands Inventory
The National Wetlands Inventory (NWI) is a national assessment of wetland resources, conducted by
the United States Fish and Wildlife Service between 1988 and 1992 within the state of Minnesota.
The NWI survey was based strictly on aerial photography reconnaissance and interpretation, thereby
being less accurate than the field-verified survey information collected for this project. However,
the NWI coverage is useful in giving an estimate of the extent (i.e. approximate geographic location)
and type (i.e. system, hydrologic regime, and predominant vegetation types) of wetlands within the
city (Appendix A, Figure 3).
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 2 of 28
Hennepin County Soil Survey
A digital version of the Soil Survey of Hennepin County was used to assess the historic and current
soil types that occur within the city (Appendix A, Figure 4). The soils of western Hennepin County
are predominantly fine textured silt loams and clay loams, which tend to support mesic native plant
communities in the uplands (such as mesic oak forest, maple basswood forest, and mesic prairie).
Furthermore, these soils are well suited for agricultural crops such as corn and soybeans, as well as
pasture lands. In addition, poorly drained landscape depressions are frequent to this portion of
western Hennepin County, and tend to support hydrophytic vegetation (i.e., wetland plants such as
sedges, grasses, rushes, and wetland herbs) and organic soil accumulation. According to the soil
survey, the predominant upland soil types within the City of Minnetrista are as follows: Lester,
Kilkenny, Hayden, and Erin loams. The most common hydric soils within the city include: Hamel,
Klossner, and Boots. During the land cover classification process, the soil survey is very useful in
determining if land cover types occur on hydric (i.e., poorly drained or wet) or non-hydric (i.e., welldrained or upland) soils, especially when classifying crops land and herbaceous vegetation types.
Minnesota County Biological Survey
In 1998, the Minnesota County Biological Survey (MCBS) conducted a comprehensive inventory of
remaining high quality natural communities and rare plant and animal species within Hennepin,
Carver, and Scott Counties (MCBS, 1998). Although much of the remnant natural vegetation within
the City of Minnetrista was reviewed through aerial photography and cursory ground surveys, only a
small subset of these remnants were of high enough quality to be surveyed in detail and included in
the county biological survey. Other remnants where either too degraded or too small in size to be
considered of high enough quality for inclusion in the survey.
Within the City of Minnetrista, ten natural community polygons were recorded by the county
biological survey. Of these, six where maple-basswood forest remnants (two of which are on the
very southern edge of section 35), two where tamarack swamp (in section 15), one cattail marsh was
documented in section 15, and a small area of lowland hardwood forest was documented on the
southern edge of section 35 (Appendix A, Figure 5).
Within one mile of the Minnetrista city boundary, several other natural community remnants where
included in the county biological survey, including numerous maple-basswood forest tracts, lowland
hardwood forests, cattail marshes, and a tamarack swamp. Most of these outlying natural
community remnants are south of sections 34 and 35, along the northern edge of Victoria and
Laketown Township. Although these communities do not occur within the city, they are important
resources within close proximity to the city, and may be worthy of consideration in future city and
regional open space planning efforts (see Appendix A, Figure 3).
The 1998 MCBS survey of Hennepin, Carver, and Scott Counties did not document any rare plant or
animal species within the City of Minnetrista. The only rare species record within close proximity to
Minnetrista is a rare fish, the pugnose shiner (Notropis anogenus). The pugnose shiner is a Special
Concern species in the state of Minnesota, and this record was last verified in 1969 within Cooks
Bay of Lake Minnetonka in Mound, Minnesota.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 3 of 28
LAND COVER CLASSIFICATION METHODOLOGY:
The MLCCS methodology was used to classify land cover within the City of Minnetrista. The full
methodology is described in detail within the MLCCS training manual (Version 4.2, March 2001)
and is included in Appendix C, of this report. A brief explanation of the method, and its application
to this project follows
The Minnesota Land Cover Classification method provides a five-level hierarchical system of land
cover codes and descriptions than can be used to describe natural land cover types (i.e., forests,
prairies, wetlands, shrub lands, etc.), and cultural land cover types (i.e., developed/ impervious areas,
agricultural fields, pastures and managed grasslands, quarries, etc.). Each level of the system
represents an increased level of detail in land cover classification and description, with level 1 being
the least detailed and level 5 being the most detailed. For the purposes of this project, all land cover
within the city was described to the greatest level of detail possible (i.e. levels 4 and 5 in most cases,
with the exception of some open water cover types which are only able to be classified to level 3
under this system).
In fall of 2001, the Hennepin Conservation District plotted 2000 true-color low altitude aerial
photographs for all sections within the City of Minnetrista. Critical Connections, Inc. used these
print outs as base maps to begin remote (i.e. off-site) classification of land cover types within the
city. Off-site interpretation of land cover types was aided by the use of 1994 color infrared aerial
photographs. In addition to color infrared photography, available data layers such as the National
Wetlands Inventory, the Hennepin County Soil Survey, and past crop information where used to aid
in offsite interpretation of land cover.
In October of 2001, field checking of off-site land cover classifications began. Several private
landowners within the city did not permit the project ecologist to access their land, thereby limiting,
in some cases, the degree of detail possible in land cover classification and natural community
quality assessment.
Minnesota Land Cover Classification System Modifiers
Several MLCCS modifiers were assessed in the field while conducting the land cover classification
of Minnetrista. These modifiers were assessed based on the methodology and definitions provided
in the MLCCS training manual (Appendix C). Once assessed, the modifier values were entered into
the GIS database for each land cover polygon.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 4 of 28
Natural quality modifier (M_33x)
The M_33x modifier was developed as part of MLCCS methodology as a cursory method to assess
the general natural quality of natural community and semi-natural land cover types. This modifier
has three general categories: High Quality Natural Community (331), Medium Quality Natural
Community (332), and Low Quality Natural Community (333). However, the assessment method is
based on general ecological variables, the method is applied in the same manner for all natural
community types. The following is the description of the M_33x modifier from the MLCCS training
manual:
331 - High quality natural community:
High quality examples of natural communities include a large portion of the species typical of the
community (see the community descriptions section, page 17). Few weedy plants are present.
(Weedy species can be native or non-native and are typical of disturbed areas. In forests weedy
species include boxelder, buckthorn, prickly ash, and garlic mustard; in prairies they include red
cedar, sumac, brome grass, and Kentucky blue-grass.) Most natural processes are occurring,
including disturbances such as fire or flooding, if appropriate. There is little or no evidence of
human disturbances, such as logging or livestock grazing.
332 - Medium quality natural community:
Medium quality examples of natural communities lack many of the species typical of the
community. Weedy species may be abundant, but they are not dominant over the typical native
species. (In communities with multiple layers of vegetation, weedy species are not dominant in any
layer.) Natural processes may have changed and there may be evidence of human disturbance, but
the nature of the community has not been altered beyond recognition.
333 - Low quality (natural community or semi-natural land):
In low quality examples of natural communities weedy species are dominant in any or all layers of
vegetation. Natural processes are highly altered and there are extensive human disturbances. The
community may not resemble any naturally occurring community (i.e. one described by DNR
Natural Heritage or NVCS).
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 5 of 28
Invasive species modifiers (M_4xx)
The M_4xx modifiers represent invasive plant species occurring within land cover polygons. For
the purpose of this project, the percent cover of each species of interest was estimated (rather than
simply providing a presence/absence value as specified in the MLCCS training manual, see
Appendix C). These species are important to track due to their invasive nature and potential threats
to native plant communities and biological diversity of native habitats. The cover classes used to
assess invasive species aerial cover (i.e. as viewed from above) is a follows:
Cover Class
Description
0
No Cover (species not observed)
1
1 – 5% Aerial Cover
2
6 – 25% Aerial Cover
3
26 – 50% Aerial Cover
4
51 – 75% Aerial Cover
5
76 – 100% Aerial Cover
The following is a list of invasive plant species and their associated modifier numbers that were
assessed for aerial coverage within land cover polygons within the City of Minnetrista:
Modifier Number
Common Name
Scientific Name
Growth Form
M_402
Purple Loosestrife
Lythrum salicaria
Herbaceous Perennial (Forb)
M_408
Common Buckthorn
Rhamnus cathartica
Understory Shrub/Small Tree
M_412
Reed Canary Grass
Phalaris arundinacea
Herbaceous Perennial (Grass)
Field checking modifiers
A field-checking modifier is provided in the GIS land cover database. This modifier indicates the
degree to which an individual polygon was checked in the field during the land cover assessment.
Most of the polygons within this project where partially observed (i.e. field check level 2). The
following is a list of field check modifier values and their associated description:
Field Check Level
1
Description
Visited Entirely
2
Visited Partially
3
Viewed From Edge
4
Viewed From A Distance
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 6 of 28
NATURAL RESOURCE INVENTORY AND ASSESSMENT METHODOLOGY:
Natural Community Quality Assessment
During the field checking of natural community land cover types, the project ecologist assessed the
overall ecological quality of natural vegetation remnants. In addition to assigning a natural
community quality modifier (M_33X) to natural and semi-natural land cover types, all natural
community remnants where assessed for their relative ecological quality using a more detailed,
community-specific methodology developed by the Minnesota Department of Natural Resources’
Natural Heritage and Non-game Research Program and the Minnesota County Biological Survey.
These DNR assessment protocols have been applied and refined for most natural community types
found within the Minneapolis/Saint Paul metropolitan area, and have been used as the assessment
methodology for the biological surveys of all the metropolitan counties. In some cases, the DNR
assessment protocols were slightly modified by the project ecologist to account for the range of
quality and conditions observed within the City of Minnetrista. Natural community assessment
protocols are provided in Appendix D of this report.
Within the GIS coverage and database for Minnetrista’s land cover, both the natural community
quality modifier (M_33X) and the Natural Heritage ranking scheme (A, B, C, and D) are provided.
Rare Species
As a result of the October 2001 start date of this project, it was not possible to collect detailed
floristic information within Minnetrista’s natural community remnants. Detailed floristic surveys
and rare species assessments are most appropriately and successfully conducted during the growing
season months (i.e., April through September in central Minnesota).
No new records of rare plants or animals where found while conducting cursory rare plant surveys
within Minnetrista’s remaining natural areas in the fall of 2001. However, several small areas of
suitable, moderate-quality habitat where observed that have the potential to harbor state-listed plant
species. The following are lists of potential rare species by habitat type that should be searched for
during the growing season (i.e., April through September) within the City of Minnetrista’s remaining
moderate natural community remnants (i.e. B and C rank communities). It is likely that at least
some of the natural community remnants within the city support rare species populations.
Maple Basswood Forest:
Common Name
Handsome sedge
Plantain-leaved sedge
Big tick-trefoil
Stemless tick-trefoil
Goldie’s fern
One-flowered broomrape
Ginseng
Snow trillium
Scientific Name
Carex formosa
Carex plantaginea
Desmodium cuspidatum
Desmodium nudiflorum
Dryopteris goldiana
Orobanche uniflora
Panax quinquefolia
Trillium nivale
Minnesota Status
Endangered
Endangered
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 7 of 28
Red Cedar Woodlands, Oak Woodland-Brushlands, and Savannas:
Common Name
Kitten-tails
Hill’s thistle
Scientific Name
Besseya bullii
Cirsium hillii
Minnesota Status
Threatened
Special Concern
Scientific Name
Carex plantaginea
Desmodium cuspidatum
Desmodium nudiflorum
Dryopteris goldiana
Panax quinquefolia
Trillium nivale
Minnesota Status
Endangered
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Scientific Name
Baptisia alba
Cypripedium candidum
Desmodium illinoense
Eryngium yuccifolium
Valeriana edulis
Minnesota Status
Special Concern
Special Concern
Special Concern
Special Concern
Threatened
Scientific Name
Juncus marginatus
Cypripedium candidum
Platanthera clavellata
Polygala cruciata
Rotala ramosior
Scleria triglomerata
Valeriana edulis
Viola lanceolata
Xyris torta
Minnesota Status
Special Concern
Special Concern
Endangered
Endangered
Threatened
Endangered
Threatened
Threatened
Endangered
Scientific Name
Decodon verticillatus
Utricularia gibba
Viola lanceolata
Xyris torta
Minnesota Status
Special Concern
Tracked by the DNR (Non-listed)
Threatened
Endangered
Oak Forest:
Common Name
Plantain-leaved sedge
Big tick-trefoil
Stemless tick-trefoil
Goldie’s fern
Ginseng
Snow trillium
Mesic Prairie:
Common Name
White wild indigo
Small white lady’s slipper
Illinois tick-trefoil
Rattlesnake master
Valerian
Wet Meadow:
Common Name
Marginated rush
Small white lady’s slipper
Club-spur orchid
Cross-leaved milkwort
Tooth cup
Tall nut rush
Valerian
Lance leaved violet
Twisted yellow eyed grass
Rich Fen:
Common Name
Water willow
Humped bladderwort
Lance leaved violet
Twisted yellow-eyed grass
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 8 of 28
Mixed Emergent Marsh:
Common Name
Water willow
Walter’s barnyard grass
Scientific Name
Decodon verticillatus
Echinochloa walteri
Minnesota Status
Special Concern
Tracked by DNR (Non-listed)
Scientific Name
Decodon verticillatus
Minnesota Status
Special Concern
Scientific Name
Polygonum arifolium
Minnesota Status
Tracked by the DNR (Non-listed)
Scientific Name
Polygonum arifolium
Carex formosa
Trillium nivale
Minnesota Status
Tracked by the DNR (Non-listed)
Endangered
Special Concern
Scientific Name
Decodon verticillatus
Platanthera clavellata
Polygonum arifolium
Cypripedium arietinum
Viola lanceolata
Xyris torta
Minnesota Status
Special Concern
Special Concern
Tracked by the DNR (Non-listed)
Threatened
Threatened
Endangered
Cattail Marsh:
Common Name
Water willow
Shrub Swamps:
Common Name
Halberd-leaved tear thumb
Lowland Hardwood Forest:
Common Name
Halberd-leaved tear thumb
Handsome sedge
Snow trillium
Tamarack Swamp:
Common Name
Water willow
Club spur orchid
Halberd-leaved tear thumb
Ram’s head lady slipper
Lance leaved violet
Twisted yellow-eyed grass
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 9 of 28
LAND COVER CLASSIFICATION RESULTS:
Land cover was classified to Levels 4 and 5 for all of the 19,805 acres within the City of Minnetrista.
91 unique land cover codes were used to describe 2,340 individual land cover polygons within the
city. Polygon size ranged from under .25 acres (in the case of small farm ponds and isolated
wetlands), to 1,340 acres (ex. large bays of western Lake Minnetonka).
According to a quantitative analysis of Minnetrista’s land cover, the most common land cover types
within the city are planted and maintained vegetation types (20000’s), which include agricultural
crops, hayfields, and pastures (5,427 acres in all, 27.4% of the total land cover). Over 19 percent of
Minnetrista’s land cover falls within the developed land category (10000’s), which includes
residential areas, farmsteads, commercial lands, and other land with greater than four percent
impervious surfaces (3,833 acres, 19.3%).
Of the natural and semi-natural (non-native species dominated) land cover types, herbaceous
vegetation types (60000’s) were most prevalent. The herbaceous land cover types comprised 21.3
percent of Minnetrista’s land cover (4,224 acres in all), and included natural communities such as
wet meadows, cattail marshes, rich fens, mixed emergent marshes, prairies, and non-native
dominated cover types such as reed-canary grass dominated wetlands, agricultural old fields, and
other fallow land.
Forest cover represented an important part of Minnetrista’s land cover, comprising almost 10 percent
of the city’s land cover (1,927 acres, 9.7%). Forest cover types (30000’s) within the city included
native community remnants such as maple-basswood forest, oak forest, lowland hardwood forest,
and floodplain forest. Non-native forest types within the city were predominantly disturbed second
growth forest types comprised of elm, box elder, ash, Cottonwood, and occasional basswood, maple,
and oak.
Open water land cover types (90000’s) accounted for over 16 percent of the city’s land cover,
covering 3,205 acres in all. Whaletail Lake, a 514 acre lake within sections 16, 17, 20, and 21 of the
city, is an important lacustrine resource, providing wildlife habitat and recreational opportunities to
the citizens of Minnetrista and adjacent communities. Other large lakes within the City of
Minnetrista include Ox Yoke Lake in the northeast corner of the city, Langdon Lake, Long Lake,
and the western edge of Lake Minnetonka, in eastern Minnetrista.
Both the woodland and shrubland land cover types (40000’s and 50000’s respectively) represent a
relatively insignificant portion of the City’s total land cover. Woodlands comprised almost 5 percent
of the city’s land cover (887 acres), and were typically degraded deciduous woodland dominated by
elm, box elder, ash, and cottonwood, or less commonly red cedar woodland and second growth oak
woodland/brushland. Shrublands comprised only 2 percent of the land cover, and were
predominantly associated with wetland systems (321 acres total).
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 10 of 28
Chart 1 summarizes general land cover types (MLCCS Level 1) by acreage within the city.
Land cover for the City of Minnetrista at MLCCS Level 1 (Figure 6) and Level 3 (Figure 7) are
provided in Appendix A. In addition, a digital version of the land cover data has been provided to
the City of Minnetrista and to the Hennepin Conservation District to be used within a geographic
information system (GIS). A summary of acreages by land cover type for MLCCS Level 1
(Table 1), Level 3 (Table 2), and Level 4/5 (Table 3) is given in Appendix B.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 11 of 28
NATURAL RESOURCE INVENTORY RESULTS:
Throughout the City of Minnetrista, 222 individual natural community remnants were documented
and assessed for their ecological quality, comprising 2,602 acres of land cover in all. These 222
remnants were comprised of sixteen distinct natural community types (five forest types, three
woodland types, two shrubland types, four herbaceous wetland types, and one upland grassland
type). The following is a summary of each natural community type, with general descriptions of the
community and quality rankings occurring within the City.
Forests (Upland)
Mesic Oak Forests (MLCCS Code 32112 / 14.5 Total Acres)
Within Minnetrista, twenty-one mesic oak forest remnants were documented. Twelve were ranked as
C-quality, and nine were ranked as D-quality. The sizes of these remnants ranged from 1.1 acres to
23.9 acres in size.
Northern red oaks (Quercus ellipsoidalis), white oaks (Quercus alba), or bur oaks (Quercus
macrocarpa) dominate mesic stands of oak forest. These stands occur on sites that had fewer severe
fires before European settlement than the sites on which dry mixed oak forest occurs. These mesic
stands most likely were always forest, rather than woodland or savanna. They have tall (> 20
meters), straight, single-stemmed trees that lack spreading lower branches. Commonly, mesic firesensitive tree species are present with the oaks in these stands, especially in the understory. These
species include basswood (Tilia americana), green ash (Fraxinus americana), bitternut hickory, bigtoothed aspen (Populus grandidentata), and butternut.
The shrub layer in mesic stands is sparser than in dry stands and, correspondingly, the forb layer is
denser and more diverse and there are more graminoid species. Like the drier stands, however, there
is little oak regeneration, and most mesic oak forests appear to be succeeding to maple-basswood
forest. Heavy selective logging of the oaks in mesic stands may accelerate this trend, producing
young stands of maple-basswood forest. The mesic stands often grade into drier stands of maplebasswood forest, but differ from them by having a somewhat denser shrub layer and the herbs
woodrush (Luzula acuminata) and pointed-leaved tick-trefoil (Desmodium glutinosum) in their
understory.
Natural stands of mesic oak forest are rare in Minnesota. Drier stands are more common, in part
because relative to the mesic forests they occur on sites with soils less suitable for cultivation.
Maple Basswood Forest (MLCCS Code 32150 / 1,285.8 Total Acres)
Seventy-eight maple-basswood forest remnants were documented within the city. Of these, thirteen
were ranked as B-quality, twenty-eight were ranked as C-quality, and thirty-seven were ranked as Dquality. The sizes of the maple-basswood remnants within the city ranged from 1.2 acres to 131.1
acres in size. The highest quality examples of maple-basswood forest (B-rank) within the city were
documented along steep hillsides near Long Lake and Whaletail Lake, and on gently rolling sites in
the southeast corner of the city.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 12 of 28
Maple-basswood forest is a mesic community of the deciduous forest-woodland zone, especially the
portion from southeastern to west-central Minnesota. It also occurs occasionally in the coniferhardwood forest zone and as isolated stands in the prairie zone on sites well protected from fire.
The tree canopy of Maple-basswood forests is dominated mostly by basswoods (Tilia americana),
sugar maples (Acer saccharum), and (formerly) American elms (Ulmus americana). Other mesic
trees, such as slippery elms (Ulmus rubra), northern red oaks (Quercus ellipsoidalis), bur oaks
(Quercus macrocarpa), white ashes (Fraxinus pennsylvanicum), and green ashes (Fraxinus
americanum) are sometimes dominant locally. The canopy is very dense, with tall, straight,
relatively narrow-crowned trees. The understory is multi-layered and patchy. It is composed of
saplings and seedlings of the canopy species (especially sugar maple), along with American
hornbeam, ironwood, bitternut hickory, pagoda dogwood, and leatherwood.
Because the tree canopy permits so little light to reach the forest floor during the summer, Maplebasswood forests have a suite of forb species that bloom, produce seeds, and die back in May and
early June before tree leaves are fully developed. These species--the spring ephemerals and the
winter annuals--include spring beauties (Claytonia spp.), Dutchman's breeches (Dicentra
cucullaria), trout-lilies (Erythronium spp.), and cleavers (Galium aparine). Other herbs, such as the
sedge Carex pedunculata, bottlebrush grass (Hystrix patula), and bearded short-husk (Brachyelytrum
erectum), are commonly present in the groundlayer but usually not abundant.
Maple-basswood forest occurs only on protected sites, where catastrophic forest crown fires were
rare historically. Across most of its range, the community develops most commonly on well-drained
loamy soils that lack mottling or other evidence of water-table levels within the tree-rooting zone. In
north-central Minnesota, maple-basswood forests develop on soils with fine-textured subsurface
layers that slow the downward movement of water and nutrients. Maple-basswood forest is a latesuccessional community, tending to succeed mixed oak forest (and other forest types) on mesic sites.
It is self-perpetuating in the absence of catastrophic disturbance and climate change because the
dominant tree species readily reproduce by gap-phase replacement. The very shade-tolerant sugar
maple seedlings and saplings, especially, may exist in a suppressed state in the understory for many
years until the death of a mature tree when one or a few grow rapidly into the canopy gap. Maplebasswood forests often develop into old-growth forests, because catastrophic disturbances are rare in
the community and because the dominant tree species are long-lived (> 250 years). The trend in
most stands of maple-basswood forest is toward greater dominance by sugar maple.
Maple-basswood forest grades into oak forest where the frequency of fire increases in the landscape.
It grades into lowland hardwood forest in low areas where elms and ashes become more abundant
and where the water table is at least seasonally within the tree rooting zone. Conifers are absent or
uncommon in most of the range of maple-basswood forest, but grow with sugar maple, basswood,
and other mesic species in northeastern and southeastern Minnesota. The mixed stands in
northeastern Minnesota are classified as Northern Hardwood Forest. In southeastern Minnesota they
are classified as White-Pine Hardwood forest.
Undisturbed stands of maple-basswood forest are rare in Minnesota. The soils on which the forest
grows are suitable for cultivation so much of the community has been cleared for cropland.
Remaining stands have often been grazed or selectively cut for lumber or fuel wood. Heavy grazing
causes compaction of the soils and the almost complete destruction of the understory, resulting in
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even-aged woodlots with large mature trees in the canopy, little reproduction, and few native shrubs
and herbs. Selective logging of the less shade-tolerant species (northern red oak, white oak, bitternut
hickory, and walnut) has been common since European settlement, and has hastened dominance by
sugar maple and basswood in many stands. The composition of the community has also been altered
throughout its range by Dutch elm disease, which has killed most of the mature elm trees, and in
many stands by the loss of interior ground layer species following forest fragmentation. Common
buckthorn (Rhamnus cathartica) and Tartarian honeysuckle (Lonicera tatarica) sometimes invade
stands of maple-basswood forest, but rarely attain the high densities they may have in oak forest.
Maple-sugaring is one human activity associated with maple-basswood forests that appears to have
little impact on the structure and composition of the community, as some of the best remaining tracts
of maple-basswood forest have long histories of maple sugar production.
Forests (Lowland)
Tamarack Swamps (MLCCS Code 31210 / 14.9 Total Acres)
Eight tamarack swamps were documented within Minnetrista, seven were ranked as C-quality, and
one was ranked as D-quality. The sizes of these remnants ranged from 0.4 acres to 4.4 acres in size.
The tamarack swamps within the city are relatively young stands, with most of the tamarack (Larix
laricina) under 10 meters in height. In addition, most of these remnants have invasive species such
as cattails (Typha spp.), reed canary grass (Phalaris arundinacea), and purple loosestrife (Lythrum
salicaria) encroaching into the herbaceous layer. Nonetheless, Minnetrista lies within the
southwestern range of this plant community within Minnesota, and therefore, these remnants are
somewhat rare and unique to the region.
Tamarack swamp is present throughout the deciduous forest-woodland and conifer-hardwood forest
zones of Minnesota. It occurs on minerotrophic muck and shallow peat along rivers and in shallow
lake basins, and on nutrient-poor, mildly-acidic to acidic peat in ice-block basins or large peatland
systems. Tamarack is either the only canopy species or is mixed with black spruce, paper birch,
yellow birch, white pine, black ash, American elm, or red maple. The sedge Carex stricta is
common under relatively open stands of tamarack; cyperus-like sedge (Carex pseudo-cyperus) and
black chokeberry (Aronia melanocarpa) are often present on tear-drop islands in large peatland
complexes.
In the absence of catastrophic disturbances, tamarack swamps may succeed shrub swamps, rich fens,
poor fens, and possibly hardwood swamp forests. Fire, flooding, and insect infestations (e.g., larch
sawfly) often reverse this succession. Wind throw, disease, and selective cutting of tamaracks in
dense stands help maintain tamarack cover by creating gaps in the canopy in which the very shadeintolerant tamarack seedlings and saplings are able to grow.
Tamarack swamp differs from mixed hardwood swamp in part by having at least 50% of its canopy
cover formed by tamarack. Tamarack swamp differs from bog communities in the pH of its surface
waters and by having minerotrophic species that do not occur in true bogs [such as bog birch (Betula
pumila), several sedge species (Carex leptalea, C. paupercula, C. tenuiflora), swamp loosestrife
(Lysimachia thyrsiflora), marsh cinquefoil (Potentilla palustris), willow (Salix pedicellaris), and
northern white cedar (Thuja occidentalis)].
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Lowland Hardwood Forest (MLCCS Code 32220 / 30.2 Total Acres)
Nine lowland hardwood forests were documented within the city. All were given a quality ranking
of C. The lowland hardwood forest remnants ranged in size from 11.4 acres to 30.1 acres.
Lowland hardwood forest is a wet-mesic forest that is present throughout Minnesota. It is
transitional between the terrestrial and palustrine systems, occurring on sites with seasonally high
water tables (within the tree-rooting zone) but that do not flood regularly and that have mineral
rather than peat soils. In accord with the poorly drained sites on which the Lowland hardwood
forests occur, species tolerant of periodic soil saturation dominate the tree canopy. American elms
and black ashes are common canopy dominants, but most stands are mixed, with slippery elms, rock
elms, basswoods, bur oaks, hackberries, yellow birches, green ashes, black ashes, quaking aspens,
balsam poplars, and paper birches as important species. The tall-shrub layer is usually discontinuous
and is composed of a mixture of upland and lowland shrubs. The ground layer is composed mostly
of upland herbs that do not root to the water-table.
Lowland hardwood forest usually occurs in fire-protected areas, although even in unprotected areas
the community burns infrequently because the woody vegetation is usually hydrated, especially in
the spring. Lowland Hardwood Forest soils differ from Hardwood Swamp Forest soils by being
mineral rather than peaty and from the mineral soils of other mesic upland forest types by being
seasonally saturated (at depths greater than 0.5 meters).
Lowland hardwood forest is often composed of late-successional species, but few stands in
Minnesota have old canopy trees, presumably because of wind throw and infrequent episodes of
killing floods. Lowland hardwood forest is topographically transitional between upland forests and
forested peatlands and is best developed on flat terrain where such transition zones are broad (e.g.,
on river terraces above normal flood levels, on loamy ground moraine, and on drumlin fields).
Floodplain Forests (MLCCS Code 32210 / 24.4 Total Acres)
Three floodplain forests were documented within the city. One remnant was given a B-quality
ranking and two were ranked as C-quality. These remnants were 1.7, 5.2, and 17.5 acres in size.
Floodplain forest is a seasonally wet forest community that occurs throughout Minnesota on the
active floodplains of major rivers and their tributary streams. The canopy of the community is
dominated by deciduous tree species tolerant of inundation, abrasion, and other disturbances
associated with flooding. The canopy is variable in composition, either composed of a mixture of
tree species or strongly dominated by a single tree species.
The species composition of floodplain forests varies both geographically and in relation to such
features as substrate type or flood cycles. In southern Minnesota, silver maples, black willows, and
cottonwoods are common canopy dominants. They occur either in nearly pure stands or in mixed
stands. Scattered individuals or patches of river birch, American elm, slippery elm, green ash, and
swamp white oak are also common in stands in southern Minnesota.
The tree canopy cover is highly variable within floodplain forests. The canopy is continuous in
some stands while other stands have open areas caused by repeated erosion, ice-scouring, and soil
and debris deposition, all of which prevent the growth of trees and shrubs. In recent decades, Dutch
elm disease has also caused significant canopy openings in floodplain forests in which mature
American elm trees were abundant in the canopy. Areas beneath tree-canopy openings in the forests
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are either dominated by short-lived herbaceous plants or, where erosion and disturbance from
flooding tend to be repeated and severe, remain unvegetated. The common herbaceous plants in
these open patches include those mentioned above in the floodplain forest class description.
Woodlands
Red Cedar Woodlands (MLCCS Code 41130 / 16.9 Total Acres)
Seven red cedar woodlands were documented within the city. All seven red cedar woodlands were
classified as D-quality natural communities, and ranged from 0.3 to 6.6 acres in size.
Red cedar woodlands consist of upland vegetation with >10% tree cover, of which >75% is by
conifers, mostly red cedars (Juniperus virginiana). Herbaceous species contribute <30% of the nontree cover. Red cedars sometimes form a nearly pure canopy in these communities, creating so
much shade that few other plants are present. Aspens (Populus tremuloides), oaks (Quercus spp.),
and paper birches (Betula papyrifera) are sometimes mixed in with the cedars, allowing enough light
for prickly ash (Zanthoxylum americanum), common buckthorn (Rhamnus cathartica), and Tartarian
honeysuckle (Lonicera tatarica). The red cedar woodlands within the city typically occurred on dry,
southern exposures, and had ground layers dominated by non-native grass species and shrub layers
with a high percentage of common buckthorn (R. cathartica).
Oak Woodland/Brushland (MLCCS Code 42120 / 72.3 Total Acres)
Six occurrences of oak woodland/brushland were documented within the city. Three were given a
quality ranking of C, and three were ranked as D-quality. The oak woodland/brushland remnants
ranged in size from 4.1 to 19.5 acres in size.
Oak woodland-brushland occurs on dry to mesic sites throughout the deciduous forest-woodland
zone and locally in the prairie zone near the ecotone between the prairie zone and the deciduous
forest-woodland zone. Oak woodland is floristically and structurally intermediate between oak
savanna and oak forest, with a patchy tree canopy and an understory dominated by shrubs and tree
saplings.
The principal species in the tree canopy are bur oak, northern pin oak, white oak, and northern red
oak. Aspens may form up to 70% of the tree canopy cover. The brush layer ranges in density from
sparse (with 10-30% cover), to an impenetrable thicket. It is often especially dense in openings
between clumps or groves of trees. Most of the floristic diversity in the community exists in the
brush layer, which most commonly is composed of blackberries and raspberries (Rubus spp.),
gooseberries (Ribes spp.), dogwoods (Cornus spp.), cherries (Prunus spp.), hazelnuts (Corylus spp.),
prickly ashes (Zanthoxylum americanum), and sprouts of oak (Quercus spp.) and quaking aspen.
Prairie vegetation, if present, occurs only in small openings in the tree or shrub canopy. Except in
these scattered prairie openings, the herbaceous layer is sparse and floristically poor. It is usually
composed of woodland species capable of surviving in the dense shade beneath the brush layer.
Oak woodland-brushland is a fire-maintained community. It is most common on rich sites where
trees and shrubs grow well but where recurrent fires prevent the formation of true forest.
Historically, Oak Woodland-Brushland was probably one of the most extensive community types in
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Minnesota, comprising much of the vegetation described as oak barrens, brushland, and thickets by
the early surveyors. The fires that maintained oak woodland-brushland usually started on nearby
prairies. Following the conversion of these prairies to agricultural land, oak woodland-brushland
burned less frequently and rapidly succeeded to oak forest. Oak woodland-brushland is defined
broadly enough here to include also communities in which the predominant cover is oak brush or
oak-aspen brush (that originated following fire or limited human disturbance) instead of a welldeveloped tree canopy. There are four geographic sections of oak woodland-brushland in
Minnesota. These sections may be modified in the future as more information becomes available.
In southeastern and central Minnesota, oak woodland-brushland is present on southwest-facing
slopes on the blufflands and on outwash terraces of the Mississippi River and its tributaries. It
generally occurs on more gentle slopes than bluff prairie or on lower slopes below bluff prairies.
Bur oaks (Quercus macrocarpa) are common canopy dominants and northern red oaks are common
associates. Northern pin oaks, basswoods, and black cherries may also occur in the canopy. White
oaks (Quercus alba) are rare and aspens (Populus tremuloides) are absent. Chokecherries are
common in the shrub layer, with shrub cover averaging 30-50%. On droughty sites with thin soils or
steep slopes these woodlands may persist even in the absence of fire.
In the Big Woods Section of Minnesota, oak woodlands are dominated by white oak (Quercus alba)
in areas with coarse-textured soils, such as on kames or eskers, or in areas prone to occasional fires.
Natural woodlands are now extremely rare in this section because of logging, grazing, and fire
suppression.
Mesic Oak Savanna (MLCCS Code 62130 / 10.6 Total Acres)
One mesic oak savanna was found within the City of Minnetrista. This site was given a D-quality
ranking, and was presumed to have been replanted and/or restored in the recent past. This savanna
remnant is 10.6 acres in size, and was lacking most of the representative herbaceous (ground layer)
species.
The characteristic trees of mesic oak savanna are bur oaks (Quercus macrocarpa) and to a lesser
extent northern pin oaks (Quercus ellipsoidalis). Northward, quaking aspens were probably
common in moister parts of mesic oak savannas. The stature and spacing of the oaks in the
community probably varied considerably, primarily with differences in fire history, which were
themselves related to differences in soils, landforms, and climate. Grubs and small, gnarly, opengrown trees were probably most common. The distribution of trees ranged from evenly spaced to
strongly clumped. Shrub cover, likewise, was probably quite variable. The shrub layer included
chokecherries (Prunus virginiana), low juneberries (Amelanchier humilis), gray-bark dogwoods
(Cornus foemina), wolfberries (Symphoricarpos occidentalis), and on lighter soils, prairie willows
(Salix humilis), New Jersey tea (Ceanothus americanus), and American hazelnuts (Corylus
americana). Leadplant (Amorpha canescens) was always present. The herbaceous vegetation was
dominated by species typical of mesic prairie, but herbs typical of oak woodland and oak forest were
probably present as well, especially beneath tree or shrub canopies.
Mesic oak savanna is rare throughout Minnesota. Historically, it occurred in the prairie and
deciduous forest-woodland zones. Mesic oak savanna occurred on dry-mesic to mesic, gently
undulating to moderately sloping sites. These sites were on glacial till or outwash, with soil texture
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ranging from clay loam to sandy loam. Mesic Oak Savanna generally occurred on sites where fire
was frequent enough to prevent trees and shrubs from forming closed canopies, thereby permitting
heliophilous prairie herbs to dominate the ground layer. However, fire frequencies were lower than
in prairies on similar topography and soils. Native grazing and browsing animals may also have
helped maintain the open character of mesic oak savanna. Within the deciduous forest-woodland
zone, where landscape character reduced fire frequency on a large scale, mesic oak savanna often
covered larger areas. With settlement and the suppression of prairie fires, savannas in the deciduous
forest-woodland zone that escaped clearing and cultivation quickly succeeded to woodland unless
heavily and continuously grazed. No high quality examples are known to remain in Minnesota.
Shrublands
Wet Meadow Shrub Subtype (MLCCS Code 52420 / 29.4 Total Acres)
Three wet meadow shrub subtypes were documented within the city. Two were ranked as B-quality,
and one was ranked as C-quality. These two B-ranked communities were 8.1 and 18.9 acres in size,
the C-ranked community was 2.4 acres in size. These wet meadow shrub subtypes were likely wet
meadows or rich fens, prior to the invasion of bog birch (Betula pumila), dogwood (Cornus
stolonifera), and willow (Salix spp.). However, they have retained a relatively high diversity of
herbaceous plant species and have relatively low cover of invasive species such as reed canary grass
and purple loosestrife.
This wet shrub meadow type is found in the northern prairie-forest border area within Minnesota.
Stands may occur along stream courses or adjacent to lakes or in upland depressions. Soils are wet
mineral, muck, or shallow peat (<0.5 m). Standing water is present in the spring and after heavy
rains, but the water table draws down by mid-summer. Seepage areas may also occur. Shrub cover is
at least 25 percent but does not become thick. Dominant species include Cornus sericea, Salix
bebbiana, Salix discolor, Salix petiolaris, and Spiraea alba. Herbaceous species are typical of wet
herbaceous meadows, and include several species of sedges (Carex aquatilis, C. atherodes, C.
haydenii, C. lacustris, C. lanuginosa, C. rostrata, and C. stricta), or grasses such as Canada blue
joint (Calamagrostis canadensis) and reedgrass (Calamagrostis stricta). Forbs include swamp
milkweed (Asclepias incarnata), lance-leaved aster (Aster lanceolatus), New England aster (A.
novae-angliae), swamp aster (A. puniceus), turtlehead (Chelone glabra), joe-pye weed (Eupatorium
maculatum), and common mint (Mentha arvensis).
Wet meadow shrub subtype is a wetland community comprised of 50-70% cover by tall shrubs
where peat is <0.5m deep and gaps are not dominated by emergent species >1m tall. The leaves of
typical grasses and sedges within this community are >3mm wide (such as Canada blue joint
(Calamagrostis canadensis), lake sedge (Carex lacustris), and tussock sedge(C. stricta)).
Willow Swamp (MLCCS Code 52430 / 144.7 Total Acres)
Eighteen records of willow swamp were documented within Minnetrista’s wetlands. Of these, two
were assigned B-quality rankings, and 16 were assessed at C-quality. These communities ranged in
size from 0.4 acres to 144.7 acres.
Willow swamp is a minerotrophic wetland with a canopy of medium to tall (>1m) shrubs dominated
by willows (especially pussy willow, slender willow, and Bebb's willow) and red-osier dogwood.
Other shrubs, such as speckled alder, bog birch, poison sumac, and alder buckthorn, may be common
in the tall shrub layer, although speckled alder is never the most abundant species present.
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Herbaceous species (especially graminoids) characteristic of wet meadow/fen communities are
common in the more open occurrences of the community. However, in willow swamps, unlike wet
meadow/fen communities, these graminoid-dominated patches are poorly separated from clumps of
shrubs. The most common herbs are tussock sedge (Carex stricta), prairie sedge (Carex prairea),
lake-bank sedge (Carex lacustris), broad-leaved cattail (Typha latifolia), blue-joint (Calamagrostis
canadensis), northern marsh fern (Thelypteris palustris), and jewel-weed (Impatiens capensis).
Willow swamps dominated by bog birch are closely related to the shrub subtype of rich fen but have
more minerotrophic indicator species [such as speckled alder (Alnus rugosa), holly (Ilex verticillata),
jewel-weed (Impatiens capensis), and horehound (Lycopus uniflorus)] than are present in Rich Fens.
Following fire in conifer swamps or in the shrub subtype of rich fens there may be initially a dense
cover of willows (usually balsam willow and bog willow), but these stands are best classified as
successional stages of conifer swamp or rich fen rather than as willow swamp. The dense groves of
sand-bar willow or juvenile black willow that occur on sand bars along rivers are not considered
shrub swamp communities but instead river beach communities, as they occur on mineral rather than
peat or muck substrates.
Willow swamp occurs on seasonally flooded soils with <30% tree cover and >50% cover by tall
shrubs (not dwarf-shrubs), where <50% of the shrubs are alders and gaps are dominated by emergent
species >1m tall.
Herbaceous Wetlands
Cattail Marsh (MLCCS Codes 61510, 61610 / 706.2 Total Acres)
Fifty-three cattail marshes were documented within the City of Minnetrista. Of these fifty-three
communities, forty-one were assessed as C-quality and 12 were assessed as D-quality. The cattail
marshes within the city ranged in size from 2.1 to 692.8 acres.
For the purposes of this project, cattails marshes do not include monotypic (i.e. single species) stands
of cattail with very low species diversity (not even at a D-rank). Wetlands within the city of
Minnetrista that are completely by cattails (Typha spp.) and reed canary grass (Phalaris
arundinacea) were considered non-native dominated herbaceous wetlands (MLCCS codes 61330,
61480, 61530, and 61630). Several large cattail/reed canary grass monotypes were observed within
the city, as well as hundreds of medium to small agricultural basins containing this combination of
invasive species.
Cattail marsh is an emergent marsh dominated by cattails (including Typha angustifolia, T. latifolia,
and their hybrids). It occurs most commonly along lake margins and in shallow basins, although it is
sometimes also present in river backwaters. Lacustrine cattail marshes typically have a muckbottom zone bordering the shoreline, where cattails are rooted in the bottom substrate, and a floating
mat zone, where the roots do not contact the bottom but instead the plants grow suspended in a
buoyant peaty mat. Associated species vary widely, but some of the most common ones are sedges
of the genus Carex (C. aquatilis, C. rostrata, and C. lanuginosa), bulrushes (Scirpus americanus, S.
acutus, and S. heterochaetus), and broad-leaved herbs such as northern marsh fern (Thelypteris
palustris), swamp milkweed (Asclepias incarnata), jewel-weed (Impatiens capensis), broad-leaved
arrowhead (Sagittaria latifolia), mad-dog skullcap (Scutellaria lateriflora), marsh skullcap
(Scutellaria galericulata), and blue vervain (Verbena hastata).
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Wet Meadow (MLCCS Code 61420 / 9.4 Total Acres)
Three wet meadows were encountered during the survey of Minnetrista. One meadow was assessed
as a B-quality community (1.1 acres), one as C-quality (1.6 acres), and one as D-quality (6.6 acres).
The ground layer of wet meadow communities are composed of dense, closed stands of
predominately wide-leaved sedges (e.g., Carex lacustris, C. stricta, C. aquatilis C. rostrata, C.
haydenii) or grasses (e.g., Calamagrostis canadensis, C. inexpansa). Forb cover and diversity
usually are high. Forbs such as spotted joe-pye weed (Eupatorium maculatum), common mint
(Mentha arvensis), turtlehead (Chelone glabra), and swamp milkweed (Asclepias incarnata) are
conspicuous. Shrub cover in wet meadows ranges from 0 to 70% and is composed of Bebb's
willows and pussy willows. Mosses are rare or absent.
Wet meadow occurs on wet mineral soil, muck, or shallow peat (<0.5 m). Standing water (generally
stagnant) is present in the spring and after heavy rains, but the water table is generally below the soil
surface for most of the growing season. The drawdown of the water table as the growing season
progresses enables the oxidation of dead organic matter that has accumulated on the ground surface
from previous years. This process makes available nutrients for some of the nutrient-demanding
species present in the community. Occurrences of wet meadow along stream courses or adjacent to
lakes often have fairly constant water levels relative to wet meadows in depressions or basins. On
these sites siltation may be important in maintaining high nutrient levels.
Wet meadow tends to succeed to shrub swamp communities in the absence of fire. Water-table
lowering caused by drought or by ditching promotes succession of wet meadow to shrub swamps.
Wet meadows on organic soils, like other communities that occur on organic soils, recover very
slowly, if at all, once altered by artificial flooding or draining.
Rich Fen (MLCCS Code 61460 / 21.3 Total Acres)
Within the city, three rich fen wetlands were documented, two of which were assessed as B-quality
and one as C-quality. These fens occurred within small, topographically-pronounced lake basins
near Whaletail and Long Lakes, often in association with tamarack swamps. Although this
community is somewhat historically rare in central Minnesota, there were likely many small rich fen
communities scattered throughout Minnetrista’s many small lakes. The sizes of the remaining
higher quality (B-rank) rich fens are 5.2 and 14.5 acres, and the C-rank rich fen is 1.7 acres.
Invasive weeds such as reed canary grass (Phalaris arundinacea), purple loosestrife (Lythrum
salicaria), and even cattails (Typha spp.) are encroaching on the edges of these remaining fens.
The ground layer of rich fens is dominated by wiregrass sedge (Carex lasiocarpa), brown sedge
(Carex buxbaumii), livid sedge (Carex livida), Calamagrostis neglecta, or bog reed-grass
(Calamagrostis inexpansa). Although generally open communities, Rich Fens may have up to 70%
cover of woody shrubs, especially bog birches, sage-leaved willows, and shrubby cinquefoils.
Mosses range from scarce to abundant in the community. Where mosses are abundant, the dominant
species are species other than sphagnum mosses (Sphagnum spp.).
Surface waters within the community are slightly acidic to circumneutral (pH 5.8 - 7.8) with
moderate nutrient levels. Rich fen may grade into poor fen but is distinguishable from poor fen by
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its higher species diversity and by the more frequent occurrence and greater abundance of
minerotrophic indicator species, including livid sedge (Carex livida), brown sedge (C. buxbaumii),
swamp lousewort (Pedicularis lanceolata), spike-rush (Eleocharis compressa), marsh muhly
(Muhlenbergia glomerata), and Kalm's lobelia (Lobelia kalmii).
Rich fen occurs in the conifer-hardwood forest and deciduous forest-woodland zones. There are two
geographic sections of rich fen, a Transition Section and a Boreal Section. In the Boreal Section (i.e.
northern Minnesota), rich fen usually occurs on deep peat and contains characteristically northern
species such as bog-rosemary (Andromeda glaucophylla) and other ericaceous shrubs, the bulrush
Scirpus hudsonianus, and pitcher-plant (Sarracenia purpurea). In the Transition Section (i.e. central
Minnesota) rich fen may be present on relatively shallow peat, or on very shallow, highly
decomposed, low-buoyancy peat, or even on wet mineral soil. Floristically, rich fen in the
Transition Section differs from rich fen in the Boreal Section mainly by containing prairie species,
such as grass-leaved goldenrod (Euthamia graminifolia), Sartwell's sedge (Carex sartwellii), and
wooly sedge (C. lanuginosa).
Mixed Emergent Marsh (MLCCS Code 61620 / 6.9 Total Acres)
Four mixed emergent marshes were documented within the city, three of which where assigned a Cquality rank, and one was assessed to be D-quality. The remnants ranged in size from 0.8 acres to
3.8 acres. Within all mixed emergent marsh remnants, reed canary grass (Phalaris arundinacea) is a
common invasive species, especially adjacent to agricultural lands that are contributing sediment and
nutrients directly into the marsh.
Mixed emergent marsh is a broad community type, encompassing all marshes dominated by species
other than cattails. Bulrushes are the most common dominants, especially hard-stemmed bulrush
(Scirpus acutus), river bulrush (Scirpus fluviatilis), softstem bulrush (Scirpus validus), Scirpus
americanus, and Scirpus heterochaetus. Common reed grass (Phragmites australis), spike rushes
(Eleocharis spp.), and (in some river backwaters) prairie cord grass (Spartina pectinata) are less
common dominants. In general, mixed emergent marsh tends to occur on harder pond, lake, or river
bottoms than cattail marsh and is less likely to contain the forbs that grow on the floating peat mats
present in many cattail marshes. Broad-leaved arrowhead (Sagittaria latifolia) and aquatic
macrophytes are the most common non-graminoid associates. Many mixed emergent marsh species
are sensitive to fertilizer run-off and other artificial disturbances, and disturbed mixed emergent
marshes (especially in the Prairie Zone) tend to convert to cattail marshes or become strongly
dominated by reed canary grass (Phalaris arundinacea) or common reed grass (Phragmites
australis), species that increase in abundance with disturbance.
Upland Grasslands
Mesic Prairie (MLCCS Code 61110 / 42.5 Total Acres)
Within the city, only two records of mesic prairie were encountered. Furthermore, these two prairies
were planted within the last ten years as native revegetation/restoration projects on private land. The
mesic prairie restoration areas are 4.3 and 38.2 acres in size. Prairie restorations are often much less
diverse than native prairie remnants, and often contain exotic weed species such as smooth brome
(Bromus inermis) and Kentucky blue grass (Poa pratensis) among others. No native prairie remnants
were observed within Minnetrista, although many non-native dominated upland grasslands
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 21 of 28
supported scattered native prairie grasses, such as big bluestem (Andropogon gerardii), little blue
stem (Schizachyrium scoparium), and Indian grass (Sorghastrum nutans).
Mesic prairie is a dry-mesic to wet-mesic grassland that occurs mainly in the prairie zone in southern
and western Minnesota and sporadically in the deciduous forest-woodland zone. Big bluestem
(Andropogon gerardii), Indian grass (Sorghastrum nutans), and prairie drop seed (Sporobolus
heterolepis) are the major native species on most sites, with little bluestem (Schizachyrium
scoparium) and porcupine grass (Stipa spartea) important on drier sites, and switch grass (Panicum
virgatum) and prairie cord grass (Spartina pectinata) common on wetter sites. Forb species
composition varies with site moisture, although some forb species occur on almost all sites, moist or
dry. Several low shrub or sub-shrub species are common on Upland Prairie; the most characteristic
is leadplant (Amorpha canescens). Taller brush and trees are absent or scattered, however brush or
woodland areas may be interspersed with prairie, usually in association with topographic and aquatic
features that provide protection from fire.
The most important cause of variation in species composition in prairie communities is variation in
soil moisture. The local soil moisture regime is determined by slope, aspect, proximity to the water
table, and soil texture. On a regional scale, variation in species composition is primarily caused by
climatic variation (i.e., the westward decline in precipitation and northward decline in temperature in
Minnesota).
Upland prairies occur on a range of landforms in the prairie zone, from nearly flat glacial lake plains
to steep morainic slopes. In the deciduous forest-woodland zone, prairies occur on droughty, level
outwash areas and steep south- and west-facing slopes. The pre-European settlement distribution of
prairie was related to the interaction of local fire frequency with growth rates of woody species:
where conditions were favorable for rapid growth, more frequent fires were necessary to maintain
prairie over savanna, woodland, or forest. Fragmentation of upland prairie since European
settlement has reduced fire frequency throughout the prairie and deciduous forest-woodland zones,
and most prairie remnants have more brush and trees than were present in the past. The introduced
grass Kentucky bluegrass (Poa pratensis) is present at most sites; it is a function of the site's
disturbance history.
Forbs are abundant (but usually subdominant to grasses) and have high local diversity. Forb speciescomposition also varies locally with soil moisture. There is greater regional variation among forbs
than among grasses. Common forb species include purple prairie-clover (Petalostemon purpureum),
white prairie-clover (P. candidum), ground-plum (Astragalus crassicarpus), prairie-turnip (Psoralea
esculenta), rough blazing-star (Liatris aspera), Canada goldenrod (Solidago canadensis), stiff
goldenrod (S. rigida), Missouri goldenrod (S. missouriensis), prairie thistle (Cirsium flodmanii),
smooth aster (Aster laevis), stiff sunflower (Helianthus rigidus), Maximilian sunflower (H.
maximiliani), smooth rattlesnake-root (Prenanthes racemosa), white sage (Artemisia ludoviciana),
wood lily (Lilium philadelphicum), white camas (Zigadenus elegans), heart-leaved alexanders (Zizia
aptera), prairie larkspur (Delphinium virescens), downy phlox (Phlox pilosa), hoary puccoon
(Lithospermum canescens), tall cinquefoil (Potentilla arguta), alum-root (Heuchera richardsonii),
wood-betony (Pedicularis canadensis), northern bedstraw (Galium boreale), prairie bird-foot violet
(Viola pedatifida), oval-leaved milkweed (Asclepias ovalifolia), and showy milkweed (A. speciosa).
Purple coneflower (Echinacea angustifolia) is common on drier sites in the western part of the
community's range. Leadplant, prairie rose, sand cherry, wolfberry, and prairie willow are common
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 22 of 28
low-shrub or sub-shrub species. Fragrant false indigo is common on moister sites. Trees and taller
brush often occur along the margins of wetlands adjacent to mesic prairies.
The soils in mesic prairie are predominantly mollisols with thick, dark mineral surface layers that
have high base saturation. They range in texture and drainage from silty and somewhat poorly
drained to sandy and somewhat excessively drained, with moderately well-drained to well-drained,
loamy soils being most common. Mesic prairie can grade into wet prairie on moister sites and into
the hill and sand-gravel subtypes of dry prairie on drier sites. Separation of mesic prairie from other
prairie types is based primarily on landform or substrate characteristics rather than on species
composition, as floristic boundaries between mesic prairie and other prairie types are not well
defined.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 23 of 28
RECOMMENDATIONS:
Conceptual Greenway/Open Space Corridor
For the purposes of this discussion, a greenway is defined as “privately or publicly owned corridors
of open space which often follow natural land or water features and which are primarily managed to
protect and enhance natural resources”. However, greenways can and often do incorporate corridors
for pedestrian movement (such as trial systems), active recreational spaces (such as athletic fields or
golf courses), and other public open spaces that may provide minimal ecological functions and
values. A greenway plan for the City of Minnetrista should be based on the following concepts:
• Connect large publicly owned open spaces with a natural or semi-natural vegetation corridor,
whether these lands are publicly or privately owned.
• Incorporate, connect and/or buffer the highest quality remaining natural areas within the city.
• Incorporate water resources and large permanent wetland systems within the corridor (directly or
indirectly), as wetlands, lakes, and streams provide beneficial wildlife habitat and are not likely able
to be developed
• Consider opportunities for active recreation and pedestrian movement through the greenway
system, while avoiding direct impacts to sensitive natural areas wherever possible or necessary.
Within the City of Minnetrista, there are many opportunities to develop a viable greenways system
as the city grows over the next ten to twenty years. The land cover and natural resource data indicate
that the highest quality natural vegetation remnants are clustered among Whaletail and Long Lakes,
and provide a “backbone” for a conceptual greenway alignment. Several large maple-basswood
forest stands are located to the south and east of Whaletail Lake.
Minnetrista’s lakes provide significant wildlife habitat and opportunities for recreation. Whaletail
Lake, Ox Yolk Lake, and several smaller lakes associated with Long Lake present another chain of
resources with the potential for increased landscape connectivity through a greenway system.
Several large wetland systems represent yet another opportunity to connect and buffer higher quality
natural resources and wildlife habitat corridors within the city.
Two large regional parks are located within southeastern Minnetrista, Lake Minnetonka Regional
Park and a Hennepin Parks open space just south of Whaletail Lake. Furthermore, the Carver Park
Reserve lies on the southeastern boundary or Minnetrista (south of sections 34 and 35). Furthermore,
the Luce Line Trail is an existing state trail in northwestern Minnetrista connecting the city to
adjacent communities. Another exempt railroad right-of-way is located within southern Minnetrista
and St. Bonifacius, and could be converted to a trail system to provide active recreational
opportunities and pedestrian access to a greenway system.
Figure 10 illustrates the geographic relationships of these landscape elements and offers a
conceptual greenway alignment based on these data (Appendix A). However, the concepts offered
here are preliminary assessments of opportunities within the city based on natural resource
information, and will require further development and public review. A Phase II greenway planning
grant through the Minnesota Department of Natural Resources’ Metro Greenways Planning Grant
program is one potential source of additional funding and matching resources to enable continued
open space and greenway corridor planning within the City of Minnetrista.
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 24 of 28
Information regarding the MNDNR’s Metro Greenway Planning Grant program may be found at:
www.dnr.state.mn.us/omb/financial_assistance/metrogreen_planning.html
Rare Species Surveys:
Although no rare species populations were observed during the fall 2001 surveys conducted by
Critical Connections, Inc., several the B and C rank natural communities may harbor populations of
rare flora (see page 8 of this report). The following is a list of natural community remnants that
should be surveyed further for rare species populations in future field seasons. If all sites that are
listed cannot be surveyed due to time and resources restrictions, then higher quality remnants (B
rank) should take precedence over lower quality remnants (C and D). In addition, if only one visit
per site is feasible, then mid to late summer surveys (July through August) are preferable to spring
surveys (May through June). Detailed surveys will require special permission from landowners to
access natural communities on private lands. Furthermore, these sites are summarized graphically
within Figure 10 of Appendix A.
Natural Community Type
Maple-Basswood Forest
Rank
Size
(Acres)
B
131.092
T117N R24W Sec 27, 34, and 35
May and July
B
92.649
T117N R24W Sec 15
May and July
B
72.575
T117N R24W Sec 9 and 16
May and July
B
60.555
T117N R24W Sec 15,16, and 21
May and July
B
49.176
T117N R24W Sec 16, 20 and 21
May and July
B
45.212
T117N R24W Sec 21
May and July
B
40.24
T117N R24W Sec 34 and 35
May and July
B
37.31
T117N R24W Sec 26*
May and July
B
28.154
T117N R24W Sec 34 and 35
May and July
B
18.206
T117N R24W Sec 36
May and July
Legal Description
Optimal Months to Survey
* Site is owned by The Nature Conservancy, and has likely been previously surveyed for rare species
Oak Forest Mesic Subtype
C
13.48
T117N R24W Sec 12
May and July
C
23.88
T117N R24W Sec 01
May and July
C
14.14
T117N R24W Sec 12
May and July
C
11.91
T117N R24W Sec 09
May and July
C
17.49
T117N R24W Sec 03
May and July
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 25 of 28
Natural Community Type
Tamarack Swamp
Rich Fen
Wet Meadow
Rank
Size
(Acres)
Legal Description
Optimal Months to Survey
C
4.419
T117N R24W Sec 09
July
C
3.088
T117N R24W Sec 16
July
C
0.997
T117N R24W Sec 17
July
C
0.759
T117N R24W Sec 16
July
C
0.757
T117N R24W Sec 17
July
C
0.462
T117N R24W Sec 09
July
C
2.447
T117N R24W Sec 15
July
D
1.986
T117N R24W Sec 01
July
B
14.47
T117N R24W Sec 09
May and July
B
5.16
T117N R24W Sec 09
May and July
C
1.69
T117N R24W Sec 16
May and July
B
1.624
T117N R24W Sec 26*
July
C
1.118
T117N R24W Sec 19
July
* Site is owned by The Nature Conservancy, and has likely been previously surveyed for rare species
Wet Meadow Shrub Subtype
Willow Swamp
B
18.899
T117N R24W Sec 15
July
B
8.136
T117N R24W Sec 09
July
C
2.363
T117N R24W Sec 09
July
B
38.38
T117N R24W Sec 16
July
B
22.021
T117N R24W Sec 14
July
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 26 of 28
Sites to consider for future acquisition
From an ecological perspective, the few large maple-basswood remnants remaining on private lands
within the city are likely the highest priority sites to consider for acquisition and protection in the
near future. Maple-basswood forests of this size and relative ecological quality are becoming
increasingly rare in western Hennepin County. Large mature forest stands are often preferred sites
for development large-lot residential housing developments. Furthermore, maple-basswood forests
(as with most forest types) are negatively impacted by fragmentation associated with residential
subdivision and habitat fragmentation of the forest interior. Development of these forest remnants
would further degrade the ecological quality of these relatively large stands, resulting in the loss of a
resource that is very difficult to restore or replace. For these reasons, the highest quality and largest
maple-basswood forest stands within the city should be considered as a high priority for acquisition
and/or future protection and management.
Several wetland types should also be considered for acquisition and/or cooperative management with
land owners. The rich fen and tamarack complexes associated with Long Lake are a unique and
sensitive wetland resource. Although these remnants will not likely be developed (due to current
wetland protection legislation), these wetlands will be highly sensitive to development of their
adjacent uplands. If possible, these systems should be further assessed for rare species populations
and floristic diversity. Additional field surveys may provide further information regarding the
relative quality of these wetlands.
Prioritization of natural community remnants for acquisition and/or protection should consider a
site’s proximity and function within the city’s open space and greenway corridor. Until this corridor
alignment is developed and refined, decisions regarding site acquisition should be based on site
quality, rarity of a vegetation type/community within the city or region, development pressure and
land prices. The ecological information provided within this report will need to be considered along
with land planning/zoning, demographic, and economic information to determine which sites are of
the highest public priority for acquisition and/or protection.
However, the prioritization of land for acquisition, preservation, and/or incorporation into a
landscape-scale greenway corridor requires more than ecological assessment information.
Prioritization of sites also requires public input and decision-making through the public planning
process.
Site acquisition grants through the Minnesota Department of Natural Resources’ Metro Greenways
Grant program is one potential source of matching resources to enable acquisition of high priority
natural lands and critical greenway and open space connections within the City of Minnetrista.
Information regarding this grant program may be found at:
www.dnr.state.mn.us/greenprint/letter.html
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 27 of 28
Sites to consider for future restoration and natural resource management
Although the highest quality natural communities within the proposed greenway corridor should first
be considered for preservation and acquisition, other natural, semi-natural, and agricultural lands
should be considered for restoration and natural resource management.
Semi-natural and cultural lands may surround or offer potential connection between high quality
natural communities. In such cases, the city may consider acquiring and restoring low-quality lands
that offer protection and connectivity of higher quality resources within an open space or greenway
system.
Once sites are identified for restoration and/or management through the greenway planning process,
Conservation Partner grants are available through the Minnesota Department of Natural Resources’
grant programs as a potential source of matching resources to enable restoration and natural
community management within high priority natural lands within potential habitat corridors, and
semi-natural lands or agricultural areas that represent potential habitat connections within potential
habitat corridors or greenway systems. Information regarding this grant program may be found at:
www.dnr.state.mn.us/omb/financial_assistance/cons_part.html
Land Cover Classification and Natural Resource Inventory
City of Minnetrista, Minnesota
Page 28 of 28
REFERENCES
Aaseng, N.E., 1993. Minnesota’s Native Vegetation. A Key to the Natural Communities,
Version 3.1. Minnesota Department of Natural Resources Biological Report Number 20.
Saint Paul, Minnesota
Bell Museum of Natural History, 1993. Minnesota Vascular Plant Database.
www.wildflowers.umn.edu. University of Minnesota. Saint Paul, Minnesota
Coffin, B., and L. Pfannmuller, 1998. Minnesota’s Endangered Flora and Fauna. University of
Minnesota Press. Minneapolis, Minnesota
Gleason, H.A., and A Cronquist, 1991. Manual of Vascular Plants of Northeastern Unites States
and Adjacent Canada. Second Edition. New York Botanical Garden. Bronx, New York
Holmgren, Noel H., 1998. The Illustrated Companion to Gleason and Cronquist’s Manual.
Illustrations of Vascular Plants of Northeastern United States and Adjacent Canada.
New York Botanical Garden. Bronx, New York
Minnesota Department of Natural Resources, 1996. Minnesota’s List of Endangered,
Threatened, and Special Concern Species. Minnesota Natural Heritage and Nongame
Research Program. Saint Paul, Minnesota
Leete, Peter, E. Perry, and B. Richardson, 2001. Minnesota Land Cover Classification Training
Manual Version 4.2. Minnesota Department of Natural Resources, Metro Region. Saint
Paul, Minnesota
Ownbey, G., and T. Morley, 1991. Vascular Plants of Minnesota. A Checklist and Atlas.
University of Minnesota Press. Minneapolis, Minnesota
USDA/SCS, 1974. Soil Survey of Hennepin County, Minnesota. University of Minnesota
Agricultural Experiment Station, Saint Paul, Minnesota
Wheeler, G.A., 1981. A Study of the Genus Carex in Minnesota. Ph. D. Dissertation. University
of Minnesota Graduate School. Minneapolis, Minnesota
Wovcha, D., B. Delaney, and G. Nordquist, 1995. Minnesota’s St. Croix River Valley and
Anoka Sandplain. A Guide to Native Habitats. University of Minnesota Press.
Minneapolis, Minnesota
Appendix A
Figures
Appendix B
Land Cover Tables
Table 1. Level 1 Land Cover with Total Acreages for the City of Minnetrista, Minnesota.
Landcover Code
MLCCS Level 1 Description
Number of Occurrences
Total Acres
10000
20000
30000
40000
50000
60000
90000
Artificial Surfaces and Associated Areas
Planted or Cultivated Vegetation
Forests
Woodlands
Shrubland
Herbaceous Vegetation
Open Water
Totals Acres
473
562
195
198
49
759
104
2340
3816.51
5426.46
1926.92
886.58
320.54
4223.83
3204.91
19805.75
Table 2. Level 3 Land Cover with Total Acreages for the City of Minnetrista, Minnesota.
MLCCS Code
Alpha-Numeric Code
Minnesota Land Cover Classification System Description
Total Acres
11100
1.tt.CC.
Artificial surfaces with coniferous trees
27.21
11200
1.tt.CD.
Artificial surfaces with deciduous tree cover
777.98
11300
1.tt.CM.
Artificial surfaces with mixed coniferous and deciduous tree cover
158.01
13100
1.hh.CT.
Artificial surfaces with perennial grasses with sparse trees
1756.7
13200
1.hh.CG.
Artificial surfaces with perennial grasses
597.58
14100
1.mv.BP.
Buildings and/or pavement
387.51
14200
1.mv.EE.
Exposed earth
111.49
21100
2.tt.CC.
Planted, maintained or cultivated coniferous trees
13.2
21200
2.tt.CD.
Planted, maintained or cultivated deciduous trees
23.46
21300
2.tt.CM.
Planted, maintained or cultivated mixed coniferous and deciduous trees
4.53
22100
2.sv.CB.
Planted, maintained or cultivated coniferous shrubs
0.25
22200
2.sv.CO.
Planted, maintained or cultivated deciduous shrub/vine vegetation
1.85
23100
2.ph.CT.
Planted or maintained grasses with sparse tree cover
452.97
23200
2.ph.CG.
Planted or maintained grasses
761.26
23300
2.ph.CF.
Planted or maintained grasses and forbs
108.36
24100
2.ch.RC.
Row cropland
3172.24
24200
2.ch.GN.
Close grown or solid seeded cropland
888.33
31200
3.ce.WB.
Saturated coniferous forest
14.92
32100
3.de.UP.
Upland deciduous forest
1854.3
32200
3.de.WA.
Temporaily flooded deciduous forest
54.58
32400
3.de.WC.
Seasonally flooded deciduous forest
3.12
41100
4.ce.UP.
Upland coniferous woodland
18.89
42100
4.de.UP.
Upland deciduous woodland
854.86
43100
4.cd.UP.
Upland mixed coniferous-deciduous woodland
12.83
52100
5.de.UP.
Upland deciduous shrubland
52400
5.de.WC.
Seasonally flooded deciduous shrubland
313.57
61100
6.ge.TG.
Tall grassland
42.46
61200
6.ge.MG.
Medium-tall grassland
346.64
61300
6.ge.WA.
Temporarily flooded graminoid vegetation
125.13
61400
6.ge.WB.
Saturated graminoid vegetation
275.83
61500
6.ge.WC.
Seasonally flooded emergent vegetation
1698.99
61600
6.ge.WF.
Semipermanently flooded emergent vegetation
1321.14
62100
6.gt.GD.
Grassland with sparse deciduous trees
392.59
62200
6.gt.GC.
Grassland with sparse conifer or mixed deciduous/coniferous trees
12.52
64100
6.hr.SW.
Standing water hydromorphic rooted vegetation
8.51
91100
9.ri.S
92100
9.la.LC.
Limnetic open water
92500
9.la.LL.
Littoral open water
93300
9.ww.OW.
6.96
Slow moving linear open water habitat
13.43
2963.79
7.52
Open water
220.17
Total Acres
19805.75
Table 3. Level 4/5 Land Cover with Total Acreages for the City of Minnetrista, Minnesota.
MLCCS Code
Alpha-Numeric Code
11120
1.tt.CC.i25.
11% to 25% impervious cover with coniferous trees
Minnesota Land Cover Classification System Description
Total Acres
11130
1.tt.CC.i50.
26% to 50% impervious cover with coniferous trees
14.24
11210
1.tt.CD.i10.
4% to 10% impervious cover with deciduous trees
166.35
11211
1.tt.CD.i10.cOA.
Oak (forest or woodland) with 4-10% impervious cover
11219
1.tt.CD.i10.cPD.
Other deciduous trees with 4-10% impervious cover
6.39
11220
1.tt.CD.i25.
11% to 25% impervious cover with deciduous trees
534.93
11221
1.tt.CD.i25.cOA.
Oak (forest or woodland) with 11- 25% impervious cover
11223
1.tt.CD.i25.cMB.
Maple-basswood (forest) with 11- 25% impervious cover
11.97
11230
1.tt.CD.i50.
26% to 50% impervious cover with deciduous trees
44.93
12.97
6.69
4.98
11240
1.tt.CD.i75.
51% to 75% impervious cover with deciduous trees
11320
1.tt.CM.i25.
11% to 25% impervious cover with mixed coniferous/deciduous trees
1.75
11323
1.tt.CM.i25.cNF.
Northern hardwood-conifer (forest) with 11-25% impervious cover
11324
1.tt.CM.i25.cPM.
Planted mixed coniferous/deciduous trees with 11-25% impervious cover
5.48
11334
1.tt.CM.i50.cPM.
Planted mixed coniferous/deciduous trees with 26-50% impervious cover
17.12
13114
1.hh.CT.i10.cGS.
Short grasses and mixed trees with 4-10% impervious cover
111.25
13124
1.hh.CT.i25.cGS.
Short grasses and mixed trees with 11-25% impervious cover
1024.06
13125
1.hh.CT.i25.cGL.
Long grasses and mixed trees with 11-25% impervious cover
2.24
13134
1.hh.CT.i50.cGS.
Short grasses and mixed trees with 26-50% impervious cover
574.26
13135
1.hh.CT.i50.cGL.
Long grasses and mixed trees with 26-50% impervious cover
21.23
13144
1.hh.CT.i75.cGS.
Short grasses and mixed trees with 51-75% impervious cover
23.66
13211
1.hh.CG.i10.cGS.
Short grasses with 4-10% impervious cover
112.49
13212
1.hh.CG.i10.cGL.
Non-native dominated long grasses with 4-10% impervious cover
13221
1.hh.CG.i25.cGS.
Short grasses with 11-25% impervious cover
350.48
13230
1.hh.CG.i50.
26% to 50% impervious cover with perennial grasses
51.07
13231
1.hh.CG.i50.cGS.
Short grasses with 26-50% impervious cover
46.63
13241
1.hh.CG.i75.cGS.
Short grasses with 51-75% impervious cover
34.38
14113
1.mv.BP.i90.cBP.
Buildings and pavement with 76-90% impervious cover
61.53
14121
1.mv.BP.i99.cBD.
Buildings with 91-100% impervious cover
13.64
14122
1.mv.BP.i99.cPV.
Pavement with 91-100% impervious cover
312.35
14210
1.mv.EE.e10.
0% to 10% impervious cover-exposed earth
37.84
14214
1.mv.EE.e10.cOE.
Other exposed/transitional land with 0-10% impervious cover
73.65
21114
2.tt.CC.pUS.cPC.
Coniferous trees on upland soils
13.20
21213
2.tt.CD.pUS.cPD.
Deciduous trees on upland soils
23.46
127.26
8.16
2.53
21310
2.tt.CM.pUS.
Upland soils with planted, maintained or cultivated mixed coniferous/deciduous trees
4.53
22110
2.sv.CB.pUS.
Upland soils with planted, maintained or cultivated coniferous shrubs
0.25
22210
2.sv.CO.pUS.
Upland soils with planted, maintained or cultivated deciduous shrub/vine vegetation
1.85
23111
2.ph.CT.pUS.cGS.
Short grasses with sparse tree cover on upland soils
335.97
23112
2.ph.CT.pUS.cGL.
Long grasses with sparse tree cover on upland soils
37.19
23121
2.ph.CT.pHS.cGS.
Short grasses with sparse tree cover on hydric soils
74.18
23122
2.ph.CT.pHS.cGL.
Long grasses with sparse tree cover on hydric soils
23211
2.ph.CG.pUS.cGS.
Short grasses on upland soils
650.54
5.64
23212
2.ph.CG.pUS.cGL.
Long grasses on upland soils
10.96
23221
2.ph.CG.pHS.cGS.
Short grasses on hydric soils
96.12
23222
2.ph.CG.pHS.cGL.
Long grasses on hydric soils
3.65
Table 3. (continued) Level 4/5 Land Cover with Total Acreages for the City of Minnetrista, Minnesota.
MLCCS Code
Alpha-Numeric Code
23312
2.ph.CF.pUS.cGL.
24110
2.ch.RC.pUS.
24112
2.ch.RC.pUS.cCO.
Minnesota Land Cover Classification System Description
Long grasses and forbs on upland soils
Total Acres
108.36
Upland soils - cropland
42.93
Corn
1965.66
24114
2.ch.RC.pUS.cSB.
Soybeans
928.68
24122
2.ch.RC.pHS.cCO.
Corn on hydric soils
158.38
24124
2.ch.RC.pHS.cSB.
Soybeans on hydric soils
76.58
24210
2.ch.GN.pUS.
Upland soils - close grown cropland
281.33
24217
2.ch.GN.pUS.cHF.
Hayfield
438.40
24218
2.ch.GN.pUS.cOC.
All other close grown cropland on upland soils
19.67
24220
2.ch.GN.pHS.
Hydric soils - close grown cropland
64.13
24228
2.ch.GN.pHS.cHF.
Hayfield on hydric soils
73.32
24229
2.ch.GN.pHS.cOC.
All other close grown cropland on hydric soils
11.48
31210
3.ce.WB.nTS.
32112
3.de.UP.nOA.nOM.
32150
3.de.UP.nMB.
Tamarack swamp
14.92
Oak forest mesic subtype
174.57
Maple-basswood forest
1285.83
32170
3.de.UP.nBG.
Boxelder - green ash disturbed native forest
393.90
32210
3.de.WA.nFF.
Floodplain forest
24.42
32220
3.de.WA.nLH.
Lowland hardwood forest
30.16
32420
3.de.WC.nMH.
Mixed hardwood swamp - seasonally flooded
3.12
41130
4.ce.UP.nRC.
Eastern Red Cedar woodland
18.89
42120
4.de.UP.nOW.
Oak woodland-brushland
72.31
42130
4.de.UP.nDT.
Disturbed deciduous woodland
782.55
43110
4.cd.UP.nDT.
Disturbed mixed woodland
12.83
52120
5.de.UP.nNT.
Native dominated upland shrubland
6.96
52420
5.de.WC.nWR.
Wet meadow shrub subtype
29.40
52430
5.de.WC.nWI.
Willow swamp
144.69
52440
5.de.WC.nNN.
Non-native dominated seasonally flooded shrubland
139.49
61110
6.ge.TG.nMP.
Mesic prairie
42.46
61220
6.ge.MG.nNN.
Medium-tall grass non-native dominated grassland
346.64
61330
6.ge.WA.nNN.
Temporarily flooded non-native dominated grassland
125.13
61420
6.ge.WB.nWM.
Wet meadow
9.38
61460
6.ge.WB.nRF.
Rich fen
21.33
61480
6.ge.WB.nNN.
Saturated non-native dominated graminoid vegetation
245.13
61510
6.ge.WC.nCM.
Cattail marsh - seasonally flooded
61530
6.ge.WC.nNN.
Seasonally flooded non-native dominated emergent vegetation
1685.60
61610
6.ge.WF.nCM.
Cattail marsh
692.80
61620
6.ge.WF.nME.
Mixed emergent marsh
61630
6.ge.WF.nNN.
Semipermanently flooded non-native dominated vegetation
62110
6.gt.GD.nAO.
Aspen openings
62130
6.gt.GD.nMO.
Mesic oak savanna
10.59
62140
6.gt.GD.nNN.
Grassland with sparse deciduous trees - non-native dominated vegetation
380.02
62220
6.gt.GC.nNN.
Grassland with sparse conifer or mixed decid/conifer trees - non-native dominated
12.52
64120
6.hr.SW.nPW.
91100
9.ri.S
92100
9.la.LC.
92500
9.la.LL.
93300
9.ww.OW.
13.39
6.94
621.40
1.99
Midwest Pondweed Submerged Aquatic Wetland
8.51
Slow moving linear open water habitat
13.43
Limnetic open water
2963.79
Littoral open water
7.52
Open water
220.17
Total Acres
19805.75
Appendix C
Minnesota Land Cover Classification Methodology
Appendix D
Natural Community Assessment Ranking Protocols
Minnesota Natural Heritage Program Natural Community Quality Assessments
Ranking Guidelines:
Maple Basswood Forest Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Maple Basswood Forest Natural Community Remnant:
• Dominated by a combination of Acer saccharum, Tilia americana, Quercus rubra, and Ulmus
americana
• Diverse ground flora, rich in spring ephemerals (not able to be fully assessed due to timing of the
assessment)
• Closed over story canopy and complete distribution of tree size classes
• No evidence of logging or grazing
• Snags and tree boles on forest floor in various stages of decay
• Typically some old growth trees present (120+ years)
B-Rank Maple Basswood Forest Natural Community Remnant:
• Dominated by a combination of Acer saccharum, Tilia americana, Quercus rubra, and Ulmus
americana
• Intact ground layer and good tree size class distribution
• May be maintained for maple sugar production
• Selective removal of oaks is the only evident disturbance
• Dominant canopy trees typically 75-120 years old
• May have experienced light grazing in the past
C-Rank Maple Basswood Forest Natural Community Remnant:
• Young second growth stand (30-70 years) regenerating following clear-cut logging
Or…
• Heavily disturbed mature or old growth stand
• Physical structure is significantly altered by human activities
• Typical maple-basswood forest plant species are still present but accompanied by exotics or other
weedy species
• Has reasonable prospect for regaining characteristic structure and composition in the long-term (50 –
100 years)
• May have experienced light grazing in the past
D-Rank Maple Basswood Forest Natural Community Remnant:
• Some characteristic species present, enough to classify the stand as a maple-basswood forest (as
opposed to other mesic forest types)
• Very heavy logging or grazing (past or present)
• Herb layer is absent or dominated by exotic or weedy species
• Little chance of natural recovery of stand within 100 years
Oak Forest Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Oak Forest Natural Community Remnant:
• Canopy dominated by a combination of oak species, such as red oak (Quercus rubra), white oak (Q.
alba), burr oak (Q. macrocarpa) and pin oak (Q. ellipsoidalis).
• Little or no human-induced disturbance (except natural area management such as prescribed burning)
• Typically an older forest of natural origin (regenerating following natural disturbance such as fire or
wind storms)
• Shrub layer not composed predominantly of species that follow grazing, but rather is composed of
hazel, chokecherry, gray dogwood, and/or blueberry.
• Ground layer composed of native species typical to oak forests
B-Rank Oak Forest Natural Community Remnant:
• Typically mature or nearly mature forest, younger than old growth, but with intact canopy
• If logging occurred within remnant, it was either long ago (>60 years ago), very light selective
cutting, or was done as a deliberate management strategy to approximate natural disturbance such as fire
• At most, very light and occasional past grazing
C-Rank Oak Forest Natural Community Remnant:
• Often, these sites have been grazed but not heavily enough to destroy the ground layer or result in
dominance by armed shrubs (i.e. Zanthoxylum americanum (Prickly Ash) and Rhamnus cathartica
(Common Buckthorn) that characteristically establish follow heavy grazing
• If site has been logged in recent past, the community remains intact and some tree regeneration
(including oak species) is occurring
• Young second growth (20-60 years old) stands that originated with good regeneration following clear
cutting or burning
D-Rank Oak Forest Natural Community Remnant:
• Heavily cut or heavily grazed forest with a dense shrub layer of prickly ash (Zanthoxylum
americanum), current (Ribes sp.), or common buckthorn (Rhamnus cathartica)
• Ground layer generally low diversity, with either compacted soils, or very loose, exposed soils with
very few herbaceous plants, or dominated by weedy grasses and sedges or by exotic species.
Mesic Prairie Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Mesic Prairie Natural Community Remnant:
• A site that appears to have structure and composition free of disturbance by modern humans, with the
exception of management practices consistent with natural processes, such as brush cutting, controlled
burning, or even certain grazing regimes
• Often contains numerous distinct patch communities or zones that correlate with variations in
microenvironmental conditions; large changes in dominant species and floristic composition will occur
with variation from wet-mesic to dry-mesic habitats
• Non-native and/or weedy species are virtually absent
• Sites commonly have a full compliment of mesic prairie grass, sedge, forb, and shrub species
• Vegetation should not be overly slanted toward disturbance indicators, or slanted toward species that
occur during one particular part of the growing season
• Site is not exposed to herbicide, pesticide, or fertilizer drift
• Limited invasion and expansion of woody species may have occurred due to fire suppression
B-Rank Mesic Prairie Natural Community Remnant:
• Site has full complement of species, but has experienced light to moderate levels of ‘unnatural”
disturbance and relative abundances of some species may be altered
• Kentucky bluegrass (Poa pratensis), spreading bentgrass (Agrostis stolonifera), or quackgrass
(Agropyron repens) are often present at low levels of infestation
• Native disturbance indicators may be more abundant than in A-rank sites
• Site does not have more than a slight presence of smooth brome (Bromus inermis)
• In sites that have been grazed, soil compaction and hummocks should be minimal
• Composition is not strongly biased toward species that occur during one particular part of the growing
season, as may result from herbicides or mowing
C-Rank Mesic Prairie Natural Community Remnant:
• Site generally has moderate to low diversity of native prairie species
• Site has significant populations of exotic and/or weedy species due to moderate “unnatural”
disturbance
• Relatively grazing-tolerant species are usually present in higher proportions that other species in
grazed prairies, and forbs may have a disproportionately high cover. Grazing indicators include Virginia
mountain-mint (Pycnanthemum virginianum), Goldenrod (Solidago spp.), Eastern Whorled Milkweed
(Asclepias verticillata), Common Milkweed (Asclepias syriaca), Cirsium arvense Canada thistle in the
pastures here, Purple Meadow-Rue (Thalictrum dasycarpum), Flat-topped, Bushy, or Grass-leaved
Goldenrod (Euthamia graminifolia), Sunflower, (Helianthus spp.), Western Mugwort (Artemisia
ludoviciana), White Prairie Aster (Aster ericoides), and Wild-bergamot (Monarda fistulosa)
• Site may have some soil compaction from grazing, but not excessive hummocking or torn turf
• Site may be overly biased toward species that occur during one part of the growing season as a
consequence of excessive mowing, grazing, or herbicide use at one particular time of the year
• A site that has been restored using locally collected seed (collected within 15 miles of the site) may be
recovered to a point where it may be given a C rank. Such sites should not be ranked higher than C
D-Rank Mesic Prairie Natural Community Remnant:
• A heavily disturbed site with little remaining or the original community structure and composition
• Diversity of native species is low, but native species are abundant enough that the community may
still be recognized as having been mesic prairie
• Exotic, invasive, and weed species are among the dominant species present. Characteristic weeds
include Kentucky Bluegrass (Poa pratensis), Quackgrass (Agropyron repens), Spreading Bentgrass
(Agrostis stolonifera), Canada Thistle (Cirsium arvense), Sweetclover (Melilotus spp.), Smooth Brome
(Bromus inermis), and Leafy Spurge (Euphorbia esula)
• Recently restored prairies or planted prairie vegetation with seed outside of a 15 mile radius will most
often be given a D rank, unless the site meets the criteria of a C rank (see above)
Lowland Hardwood Forest Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Lowland Hardwood Forest Natural Community Remnant:
•
•
•
•
•
•
Canopy cover >70%, no logging or grazing history
Old growth (120 years old or more) or mature forest
No (or very few) exotic species present in any vegetation layer
All size classes of canopy species present
Rich herb layer including spring ephemerals (unable to be adequately assessed for this project)
Natural hydrological system intact (no major locks, dams, draining, or other hydrologic alteration)
B-Rank Lowland Hardwood Forest Natural Community Remnant:
• Mature or nearly mature forest, or old growth forest with some human-caused disturbance such as
light past grazing or long-ago selective logging, or good quality younger forest regenerating from past
natural disturbance(s) such as windstorms or natural flooding events
• No (or very few) exotic species in any vegetation layer
• All or most size classes of canopy species present
• Natural hydrologic system mostly intact
C-Rank Lowland Hardwood Forest Natural Community Remnant:
• Generally disturbed by logging or grazing, or with a highly altered hydrologic regime
• Often some exotic species in the shrub and/or ground layers, but these layers still with a good variety
and proportion of native species
• Young second growth forests following logging or burning may be included here if community
remains intact and forest regeneration is occurring
D-Rank Lowland Hardwood Forest Natural Community Remnant:
• Forest recently heavily logged, or logged long ago but not regenerating naturally (i.e., converting to
another disturbed community type or dominated by exotic species)
• Heavily grazed forests with a dense shrub layer of prickly ash (Zanthoxylum americanum), current
(Ribes sp.), or common buckthorn (Rhamnus cathartica); or with ground layer dominated by exotic
species or weedy graminoids.
Tamarack Swamp Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Tamarack Swamp Natural Community Remnant:
• A mature stand of tamarack that is the largest possible size for the physiographic setting (approaching
40 acres in south central Minnesota)
• Exhibits considerable within wetland physiognomic and community diversity (i.e., seepage areas,
differences in dominant species composition)
• Has high diversity of native wetland forest species. In general, the degree of floristic diversity
acceptable for an A-rank tamarack swamp will vary depending on the subtype, with higher floristic
diversity expected at the minerotrophic (more nutrient rich) end of the spectrum.
• A representative vegetation plot (10 meter by 10 meter) should contain at least five sedge species, 25
to 30 herbaceous species, and at least five species of deciduous shrubs.
• A stand need not be old growth to qualify as A-rank, but old growth could offset size or floristic
diversity in up ranking a stand from A to B. Old growth status should be considered in conjunction with
hydrologic integrity in determining the ultimate rank of the stand.
B-Rank Tamarack Swamp Natural Community Remnant:
• Exhibits good floristic diversity. A representative vegetation plot (10 meter by 10 meter) should
contain at least five sedge species, at least five species of deciduous shrubs, and 15 to 25 herbaceous
species.
• Lacks the internal microhabitat community diversity characteristic of an A-rank community
• A C-Rank tamarack swamp at the southern edge of its range could be ranked to B if the occurrence
contributes to the overall natural landscape diversity.
• Size of the wetland should not be considered when assigning the rank
• Natural hydrologic system mostly intact
C-Rank Tamarack Swamp Natural Community Remnant:
• Is floristically monotonous. A representative vegetation plot (10 meter by 10 meter) contains fewer
than five sedge or shrub species, and fewer than 15 herb species.
• Can exhibit limited hydrologic disturbance if the occurrence is larger than 40 acres and the impacted
areas comprises less than 5% of the wetland system
• Reed canary grass (Phalaris arundinacea) and other invasive and/or weedy species may be present,
but are not dominant
D-Rank Tamarack Swamp Natural Community Remnant:
• Has pronounced hydrologic alterations, low floristic diversity, or significant amounts or Reed Canary
Grass (Phalaris arundinacea), or other problematic weeds
Floodplain Forest Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Floodplain Forest Natural Community Remnant:
• Typically an old-growth forest (120 years or older) or a stand dominated by late successional trees
• Contains no exotic species and no human induced hydrologic alterations
• Canopy is dominated either by pure stands or by some combination of silver maple (Acer
saccharinum), green ash, American elm, slippery elm, bur oak, and swamp white oak, and possibly
cottonwood in some areas
• Has evidence of past flooding, such as water marks on trees or recently deposited soil and woody
debris
• Ground layer is diverse and dominated by native species tolerant of flooding and dense shade
• Contains some habitat diversity from natural variation in water courses over time (i.e., sloughs, vernal
pools, old depressions, and/or oxbows are present)
B-Rank Floodplain Forest Natural Community Remnant:
• A naturally occurring forest with a limited grazing history, some exotic species invasion, or limited
tree cutting…or…
• An old forest with historic hydrologic alteration (such as locks and dams on the Mississippi River) but
no other human disturbance…or…
• An old forest that originated following logging and now resembles a naturally occurring forest …or…
• A forest formerly dominated by elms that died as a result of Dutch elm disease, but is now
redeveloping canopy of native species and is otherwise of high quality
• Dominated by late successional tree species or by old trees of early successional bottomland species,
including cottonwood, aspen, black willow, and peach-leaf willow
• Ground layer is dominated by native species with at most small patches of exotic species, invasive
species, and/or agricultural weed species
C-Rank Floodplain Forest Natural Community Remnant:
• A forest with a history of moderate grazing, moderate logging, or cultivation, but that still has some
canopy cover of bottomland tree species and some native ground layer and shrub species
• A forest with late successional tree species in the canopy, a lower sub-canopy of box elder, and a
ground layer of predominantly native species
• May contain areas dominated by Reed Canary Grass (Phalaris arundinacea) or other invasive/exotic
species, but these are only small inclusions within a more diverse, native-dominated forest
D-Rank Floodplain Forest Natural Community Remnant:
• A human disturbed forest with little or no chance of natural recovery
• A forest that has been heavily logged, grazed, cultivated, and/or hydrologically altered
• A forest that is dominated with box elder in the canopy or sub-canopy, or a ground layer completely
or nearly completely dominated by exotic species, invasive species, and/or agricultural weeds.
Shrub Swamp Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Shrub Swamp Natural Community Remnant:
• Has extensive areas with sufficient native shrub cover (50-100%) to favor development of shade
tolerant flora (herbs vs. graminoids). Open areas in canopy gaps are limited
• Has no obvious impact on vegetation from flooding or lowering of water levels by human induced
activities such as road construction, ditching, or mining
• Is a sufficiently large area of a pure type, non-grading into other community types (i.e., not a mosaic)
• Origin of the shrub swamp not due to logging or draining or a fen or meadow
• No exotic species present
B-Rank Shrub Swamp Natural Community Remnant:
• A site with the above characteristics, but degraded by surface activities to a greater extent…
Or…
• A site with impacts due to water table alteration, but limited to a narrow band along a ditch, road, etc.
Overall hydrologic impacts still relatively minor in relation to the overall size of the shrub swamp
• Exotic species may be present but only at a low level and limited extent
C-Rank Shrub Swamp Natural Community Remnant:
• Structure and species composition significantly altered from its presettlement character by flooding,
lowering of water table, or surface activities/disturbances
• Has more than occasional occurrence of exotic or invasive species, or atypical shrub species,
• Maintains enough native structure and representative species so that the community is still
recognizable as a native shrub swamp
• Has had sufficient time (>30 years) since logging to establish, if type conversion from swamp forest
has taken place
D-Rank Shrub Swamp Natural Community Remnant:
• A site where the hydrology has been severely altered, or surface has been drastically disturbed such
that natural regeneration of the community is unlikely to occur
• Has low native species diversity and large populations of weed species. Common weeds include reed
canary grass (Phalaris arundinacea), stinging nettle (Urtica dioica), thistle (Cirsium arvense), Kentucky
bluegrass (Poa pratensis), common buckthorn (Rhamnus cathartica), and glossy buckthorn (Rhamnus
frangula).
Wet Meadow (and Wet Meadow Shrub Subtype) Natural Community Quality Assessment and
Ranking Guidelines:
A-Rank Wet Meadow Natural Community Remnant:
• Lacks indicators of past grazing, haying, draining, or unnatural inputs of water, salts, or nutrients
(context, knowledge of site history, and presence of conservative plant species may be necessary to
judge whether meadow is undisturbed)
• Has intact margin and has been burned where appropriate (prairie and transition zones)
• Little or no reed canary grass (Phalaris arundinacea) present
• Not surrounded by farmland (which would result in a high probability of nutrient rich runoff)
• Natural hydrologic regime
• No ditches, exactions, or dug-outs
B-Rank Wet Meadow Natural Community Remnant:
• Undisturbed central zone, but some disturbance along the margin such as the presence of reed canary
grass (Phalaris arundinacea), Kentucky blue grass (Poa pratensis), or large, monotypic stands of native
or exotic species such as sensitive fern (Onoclea sensibilis), current (Rubus spp.), blue vervain (Verbena
hastata), and cattail (Typha spp.)
• Light grazing or haying may have occurred in the past
C-Rank Wet Meadow Natural Community Remnant:
• Central meadow zone is slightly disturbed as suggested by, for example, changes in vegetation
patterns across an old fence line, ditches and spoil banks, lowered water table, and increased shrub cover
• Meadow edge is completely overgrown with tall herbs, shrubs, or aspen and other tree species
• Meadow is partially dominated by rank growth of reed canary grass (Phalaris arundinacea), tall
goldenrod (Solidago altissima), Canada goldenrod (Solidago canadensis), boneset (Eupatorium
perfoliatum), joe-pye-weed (Eupatoriadelphus spp.), or stinging nettle (Urtica dioica)
D-Rank Wet Meadow Natural Community Remnant:
• Abundant reed canary grass (Phalaris arundinacea) or other aggressive weeds
• No surrounding natural vegetation (which may be essential for the protection and recovery of the
meadow edge)
• Major changes in hydrologic regime or water quality evident
Mixed Emergent Marsh Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Mixed Emergent Marsh Natural Community Remnant:
• The community has structure and composition free of disturbance from modern humans
• Groundwater system is intact, with standing water present during most of the growing season
• There is generally some natural zonation, with species varying in accordance to soil and sediment
type, depth and permanence of standing water, and groundwater influence
• Has a diverse assemblage of native species, including emergent herbs and obligate aquatics
• Woody species are absent or very infrequent
• Exotic or invasive species are absent or nearly so
B-Rank Mixed Emergent Marsh Natural Community Remnant:
• The community is dominated by native species, with a few individuals of exotic species present
• May not have the full range of species present in an A-rank community, but is relatively diverse and
has some natural zonation
• Shows some signs of past or present human disturbance, such as light grazing, past partial drainage
that has since been blocked, or limited occurrences of exotic species
C-Rank Mixed Emergent Marsh Natural Community Remnant:
• The community has predominantly native species
• Often has exotic or invasive species present in relatively high numbers, but with significant inclusions
of native-dominated patches, and does not seem to be succeeding to a monoculture of exotics, such as
purple loosestrife (Lythrum salicaria). Common exotics include reed canary grass (Phalaris
arundinacea) and Common Reed (Phragmites australis)
• The site has a moderate amount of human induced disturbance, such as some drainage or past heavy
grazing. Furthermore, the site may have been cultivated in the past but has since been released from
agricultural uses long enough for native species to recolonize
D-Rank Mixed Emergent Marsh Natural Community Remnant:
• A site dominated by exotic species an/or weedy native species
• Significant hydrologic alterations
• Low native species diversity
• May be dominated by recent invasions of cattail (Typha spp.), following unnatural disturbances such
as impoundments, nutrient-rich runoff, dredging, introduction of road salts, etc.
Oak Woodland/Brushland Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Oak Woodland/Brushland Natural Community Remnant:
• At least half the canopy is dominated by open grown trees
• Lacks a subcanaopy
• Typically has canopy gaps throughout the site. Prairie herbs are present within the canopy gaps,
while shrubs or shade-tolerant herbs are prevalent beneath tree groves
• Has a shrub layer with few individuals of thorny or otherwise unpalatable weedy species (e.g., Ribes
missouriensis, Zanthoxylum americanum) or of forest species (e.g., Cornus alterniflora)
• Weedy Eurasian grasses such as Poa pratensis or Agrostis stolonifera are sparse or nearly absent
• Has not been heavily grazed, as evinced by the species diversity within the community or in adjacent
habitats (i.e. wetland rims)
B-Rank Oak Woodland/Brushland Natural Community Remnant:
• Has evidence of logging, grazing, etc., but these disturbances are minimal and recovery is likely over
time. Indicators of past disturbance include human-made structures (trails, fences, foundations, well,
dumps, boulder piles); dense patches of clonal shrubs such as Zanthoxylum, Rubus, Ribes, etc.
• Weedy Eurasian grasses such as Poa pratensis or Agrostis stolonifera are common but not dominant.
Native species that tend to increase during grazing are patchy or abundant in some areas. Most of the
prairie vegetation is diverse, although scattered patches of low-diversity prairie may be present
• Subcanopy present but not well defined. A few individuals of successional species (e.g., Acer,
Ostrya, Fraxinus, Carya ovata) may be present in the subcanopy
• Has substantial numbers of weedy shrubs, (e.g. Ribes missouriensis, Zanthoxylum americanum,
Lonicera tatarica, Rhamnus cathartica) but these do not dominate the shrub layer
C-Rank Oak Woodland/Brushland Natural Community Remnant:
• Site has been extensively grazed
• Soil compaction and livestock trails are obvious but not extensive
• Has few shrub species, most are thorny, unpalatable species that increase during grazing, although
these form less than 50% cover
• Weedy species are common (but not dominant)
• Subcanopy is evident, but not always distinct
• Has a ration of open-grown to forest grown trees of less than one, indicating succession to forest.
Canopy may contain shade tolerant species such as Carya ovata and Prunus serotina
D-Rank Oak Woodland/Brushland Natural Community Remnant:
• Is highly disturbed (has many disturbance indicators) and is not likely easily restorable
• Shrub layer is entirely dominated by thorny or unpalatable species (Ribes missouriensis, Rhamnus
cathartica, Zanthoxylum americanum, Lonicera tatarica) as a result of past or present over grazing
• Soil is severely compacted and/or eroded; animal trails present
• Ground layer has low species diversity, being composed mainly of just two or three native species, or
is predominantly comprised of Eurasian grasses
• The community may have succeeded to a forest structure, with a distinct subcanopy of shade tolerant
shrub species
Rich Fen Natural Community Quality Assessment and Ranking Guidelines:
A-Rank Rich Fen Natural Community Remnant:
• No obvious impact on vegetation from alteration of groundwater by activities such as road
construction, ditching, utility corridors, or mining activities. Some minor occurrence of abandoned
winter vehicle trails is acceptable.
• Drosera anglica and Drosera linearis are good indicators of pristineness
• High floral diversity because of the presence of “mud-bottomed” pools or flarks and moss-covered
ridges
• No exotic/invasive species present
B-Rank Rich Fen Natural Community Remnant:
• A site with the above characteristics, but has where disturbance by surface activities such as winter
roads or utility corridors is more extensive, or….
• A site with the above characteristics but with impacts over a small percentage of the fen surface due
to water table alteration (this may be indicated by invasion of Asclepias incarnata, Alnus incana, or
Cirsium arvense, or an increase in Chamaedaphne calyclata, Betula glandulifera, Larix laricina, or
Calamagrostis canadensis), or….
• An undisturbed site lacking floristic diversity, fairly monotypic, often with a thatch layer and
overgrown herbaceous perennial cover
• Exotic or invasive species are minimal
C-Rank Rich Fen Natural Community Remnant:
• Overall groundwater flow intact but has extensive impacts by ditches, roads, or adjacent land uses;
large portions of the fen remain intact
• Floristic diversity is moderate to low
• Exotic or invasive species are common or patchy but not becoming dominant
D-Rank Rich Fen Natural Community Remnant:
• A site where the hydrology has been severely altered or the surface is drastically disturbed (i.e.
sometimes due to peat mining, or sedimentation) such that restoration is unlikely to occur
• Floristic diversity is low
• Exotic or invasive species are common to abundant, often forming monotypic patches or stands