5.10. SR 12-20-2004
Item # 5.10.
City of
Elk ~
River- ,
MEMORANDUM
FROM:
Mayor and City Council
Michele MCPherso~ector of Planning
TO:
DATE:
December 20, 2004
SUBJECT:
Approve Natural Resources Inventory
The City Council reviewed a recommendation from the Natural Resources InventOlY at the
November 8th worksession of the Council. Attached is the abridged version of the report
for the City Council, including the map and its key.
Requested Action
The Council is asked to approve the Natural Resources Inventory.
$: \PLANNING\lv1ichele McPherson \P ARKNREC\Natural Resources Invemory\12 20 04 CC memo.doc
Table of Contents
Table of Contents........
................................................
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. i.
Introduction ........... ...... .......... ........ .......... ....... ........ ........ ....... .... .........1. .
A Brief Look at the Natural History of the Study Area........................3.
Project Methodology. .......... ......... ..................... .... ..... .......................7.
Land Cover Classification Results...................................................16.
Natural Resource Inventory Results ......... ........................ .......... .....19.
Recommendations ... ....... ... ......... ............. ...................................... .41.
Conceptual Greenways/Open Space Corridors .......................................41.
Zoning and Subdivision Ordinance Review.............................................. 42.
Parcel Review......... ..................... .......... ..................................................49.
Sites to Consider for Proactive Management/Protection .......................... 50.
General Management Strategies for Natural Communities .............55.
Appendices
Appendix A Plant Community Survey Data
Appendix B Land Cover Summary Tables
Appendix C Glossary of Technical Terms
City of Elk River. MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
List of Figures
Project Area/Property Access Map............ ..... .......... .... ...... .......... ..... 9.
MLCCS Level 1 Summary............................................................... 18.
Parcels Recommended for Alternative Development Strategies .....51.
Natural Areas of High and Moderate Quality ...................................54.
Natural Areas, Semi-natural Areas.................... Back pocket of report.
and Conceptual Greenways/Corridors
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ii
Introduction
Project Background
The City of Elk River lies in the southeast comer of Sherbume County, within 40
minutes of the large urban center of Minneapolis-St Paul, Despite this close
proximity, the area still supports a significant complement of natural areas amid farm
fields, pastures, and rural development
City staff, officials, and others recognize the role that natural areas and rural vistas
play an important role in attracting people to the area and in contributing to the quality
of life here, Local officials and residents also recognize that these natural amenities
offer concrete benefits, as well. These areas provide opportunities for active and
passive recreation, wildlife habitat, and can serve as buffers for commercial and
residential development The aesthetic qualities and desirability of these natural areas
also increases the value of properties located near them. These areas also serve
somewhat more intangible purposes that provide significant economic benefit, such as
filtering stormwater runoff. This, in tum, helps to protect groundwater quality and can
reduce flooding problems.
In the spring of 2004, the City of Elk River retained Bonestroo Natural Resources to
conduct land cover classification mapping and natural areas assessment The
process began with a public Open House held at Lion's Club Park Center in May 2004.
During the same period, aerial photos were reviewed and the owners of land parcels
greater than five acres that appeared to support natural areas were contacted by letter
respectfully requesting permission to visit potential natural areas on their property.
Field work for this inventory was conducted from July to September 2004 to coincide
with the height of plant growth for the dominant plant community types in the city
(prairie and savanna). On-the-ground vegetation surveys were accomplished using a
system adapted from classification and qualitative assessment methods similar to
those used by the MN DNR Natural Heritage Program. Information gathered in the
field was then evaluated using standardized ecological criteria developed by the
Minnesota Department of Natural Resources, providing information about natural
community type and quality.
Land cover type mapping of was accomplished using the Minnesota Land Cover
Classification System (MLCCS), Version 5.4 This mapping system is used to
distinguish between different types of land cover based on the amount and type of
City of Elk River, MN - Natural Resouce Inventory
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vegetation, as well as the amount of hard surfaces (such as pavement) present in a
particular area and incorporates natural community types recognized by the MN DNR.
This set of information was used to identify opportunities for management and
protection of natural areas in the city by private landowners and public officials alike,
with cooperation and team work in-mind. The information from this study has the
potential to be used by city staff, as well as others to enable proactive natural resource
management, including:
.:. Identify opportunities to partner with private landowners to foster stewardship of
natural areas
.:. Provide information for community planning in:
o Review of proposed developments
o Parks planning
o Surface water planning
o City code and ordinance creation/revision
Natural areas are an important part of providing identity to the places we live. They
contribute to quality of life, and provide a sense of place to each of us. The
information gathered in this study will be an important part of wisely understanding
. what activities and land uses can support while retaining natural areas that define the
character of the landscape that residents value.
Goals and Objectives of the Inventory
The Goals and Objectives for this project were to:
. Identify and inventory significant natural areas, and gather solid on-the-ground data
where access was available.
. Use a proven natural community classification and qualitative ranking methodology
to evaluate natural communities.
. Map land cover of natural and semi-natural areas using the Minnesota Land Cover
Classification System (MLCCS)
. Identify opportunities for management and protection of significant high quality
natural areas and/or concentrations of natural areas/habitats.
. Provide information to enable sound planning for the future of the city.
. Review City code and identify opportunities to enable further stewardship of natural
areas
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A Brief Look at the Natural History of the Study Area
The particular resource elements present in any area and their patterns in the
landscape are the result of historical processes, including climate, hydrology, plant and
animal migrations and interactions, and human decisions and activities. This section
very briefly describes the role these interactions have played in determining the
present day composition of natural communities and landscapes in the area.
Landscape History of the Study Area
Bedrock Geology and Glacial Landscapes
The landscape history of the area includes bedrock geology. The vast majority of the
region is mantled by debris left by glaciers, but the bedrock that is closest to the
surface in Elk River is of the Cambrian System, some 5-600 million years ago.
The topography of the area was most heavily influenced by the last period of glaciation
(the "Wisconsin Stage"), which ended in east-central Minnesota about 10,000 years
ago. During this event, glaciers sculpted the landscape and left behind a variety of
deposits, including drift/till and outwash composed of sand and gravel, and windblown
deposits of very fine sands. During the last glaciation, the Superior Lobe was the first
ice sheet to advance into from the region from the northeast, and finally retreat about
20,000 years ago. With each advance and retreat, the melting ice sheet deposited
immense piles of sand and gravel along its margins. Outwash deposits from the
Superior lobe are found in the north-central part of the city, along Highway 169 and in
a small area just southeast of downtown.
Throughout the vast majority of the city, Superior Lobe deposits are covered by those
of the Grantsburg sublobe of the Des Moines Lobe glacier. The Des Moines Lobe
entered the area from the northwest, giving rise to the Grantsburg Sublobe that moved
to the northeast, through the Twin Cities and into western Wisconsin. The Des Moines
lobe left a variety of deposits that dominate the landscape in the area, including
rugged terrain from till, outwash, and more subtle terrain from lake deposited sands
The topography, soils, and pattern of streams, lakes and wetlands that resulted from
glacial activity greatly influenced the pattern of vegetation and plant communities that
developed later in the area. Existing plant communities such as Oak Savannas and
Prairies are well-adapted to droughty soils, and developed in areas where the
landscape allowed periodic fires. Areas with a steep, rugged terrain burned less
City of Elk River, MN - Natural Resouce Inventory
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frequently and sUPPol1ed oak woodland communities, while wetlands were found in
depressions and valleys with denser, hydric soils.
After the glaciers
Immediately after the glaciers melted, spruce trees and tundra colonized the
periglacial environment. This was later followed by pine barrens and mixed boreal
forests with a bracken fern-dominated ground layer. As the climate of the region
warmed dramatically about 9,000 years ago, pines began to decline, and prairie
expanded into the region, along with elm and oak forests. The climate remained in
this warm period until about 7,000 years ago, when midgrass prairie reached its
maximum extent in Minnesota, and covered the southwest half of the state.
Prairie, oak woodlands and brush lands, and oak savanna, consisting of scattered
trees with a prairie-like ground cover, dominated the Region until about 4,000 years
ago, when the climate gradually became cooler and moister. Oak thickets spread, and
oak woodlands came to dominate some upland areas, interspersed with tall grass and
wet prairies. White pines also migrated to just northeast of Sherburne County as the
climate cooled. About 300 years ago, the climate became especially moist and cool,
and fires became less frequent. As a result, extensive forests of elm, sugar maple,
and basswood (known as the Big Woods) developed in eastern Minnesota. After this,
the major patterns of vegetation in the area at the time of European settlement were
then in place.
Influence of Landform and Climate on Vegetation Types
Plant communities that exist in any given area are the result of numerous biological
and physical factors. These work in concert to influence plant communities in often
subtle ways, and sometimes dramatic and immediate ways such as drought, or a
tornado Biological factors can include such varied things as the presence or absence
of pollinators, burrowing activities, herbivory, or over utilization of an area by a single
species or number of species.
Of the physical factors, two have a consistently strong influence in the shaping of plant
communities. These are climate and landform. The climate in east-central Minnesota
is considered to be continental and subhumid, with long, cold winters and relatively
brief, warm summers. Wide fluctuations in temperature and precipitation strongly
influence the plant communities present in the region and causes plants to be adapted
to extremes, rather than averages.
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Landforms also have a profound impact on the type of plant communities found in any
area. As was mentioned previously. the landforms of the area are primarily glacial in
origin. Direct glacial modification of the landscape, such as the deposition of till, and
moraine, and the influence of periglacial processes such as outwash, have formed the
vast majority of the landforms in this region. Most of the deposited materials
associated directly with glaciers, such as till and moraine are unsorted. These consist
of materials, which range in size from clay and fine sand to large boulders in a random
arrangement. Overall, the materials deposited in the City tend to form well-drained to
very well-drained landscapes with sands and gravels common.
In addition to the influences of climate and landform, landscape position also has a
profound impact on the type of plant communities supported. Angle, position, and
aspect of slope all strongly influence plant species that can be supported in an area.
Slope aspect plays a significant role since it tan exaggerate the influence of the sun
and the amount of water plants loose through their leaves on south- and southwest-
fating slopes making these areas more hospitable to prairie or dry oak communities.
North-facing slopes tend to be moister and have a tendency to be occupied by
woodlands/forests.
Historic InfJuence of Humans on the Landscape
Ideas about the history of Native Americans and their influence on the local landscape
are still evolving. Native Americans have probably inhabited and hunted in the area
for over 10,000 years. While their impacts were not as great as those of European
settlers, Native Americans used a wide variety of plants and animals for food, and
.
altered vegetation patterns for cultivation and by setting fire to broad expanses of
landscape. Native Americans (and European fur traders) used fire to hunt game;
create desired habitat; clear the landscape for travel, communication and defense; and
obtain firewood. While some fires in the region would have occurred naturally, the
activities of Native Americans undoubtedly accounted for the vast majority of fires.
Prairies, savannas, and oak forests are fire-dependent plant communities, and would
most likely not have been present in the Twin Cities Area at the time of European
settlement without these fires.
At the time of settlement, around 1850, the landscape of the study area supported a
rich variety of plant communities including various types of wetlands in low areas and
oak and aspen woodlands, brushlands and prairies on drier uplands. As the City
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
5
developed after the mid-1800s, more intense human activities began to change the
landscape and natural communities. In Sherburne County today, approximately 90-95
percent of the native landscape has been substantially impacted by human activities.
Examples of changes since European settlement include the following:
Roads and the railroads began to fragment forests and other communities.
Agriculture affected hydrology by draining wetlands and altering creeks.
Vegetation was altered through clearing, plowing, cessation of regular fires, and
grazing. These effects are evident in the reduction of native vegetation diversity
in meadow and forest understory and substitution of communities of low
diversity dominated by non-native plants. Soil erosion increased where native
cover was removed, adding sediments to creeks, wetlands and lakes.
Urbanization continues to fragment natural communities further with the
addition of more roads, streets and utilities. Construction of all types altars and
compacts soils, and changes the local hydrology. Large areas of impervious
surface and drainage of wetlands increases the amount of stormwater runoff
and pollutants carried to local waters.
Non-native, aggressive species like European buckthorn have been added as
landscape materials. Changes in habitat and the increasing presence of
humans in the landscape has brought changes in animal populations,
decreasing or eliminating some species like bluebirds and bison, and favoring
others such as English sparrows and white-tail deer.
Vegetation at the Time of Settlement
According to the original land survey notes (compiled in Minnesota between 1853 and
1856), the presettlement vegetation of southeastern Sherburne County was comprised
primarily of prairie and savanna in the south. Oak forest was more common in the
northeastern part of the city where it was interspersed with tamarack swamp, prairie,
and wet meadow, with small inclusions of wet prairie and lakes.
City of Elk River, MN - Natural Resouce InventolY
Bonestroo Natural Resources, September 2004
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Project Methodology
This Land Cover Classification and Natural Areas Inventory project was conducted for
the entire land area within the City of Elk River, approximately 44 square miles. A brief
summary of each of the Project methodology steps is included on the following pages.
Gather and Review Background Information
To provide a more detailed understanding of the study area, available information on
natural resource features was gathered and reviewed by ecologists. These
information resources included presettlement vegetation, biological survey information
for Sherburne County, wetland and water resource information, and the Sherburne
County soil survey.
Minnesota County Biological Survey
The Minnesota County Siological Survey (MCSS) conducted an inventory of select
remaining natural communities within Sherburne County (MCSS, 1998). Although
much of the remnant natural vegetation within the City of Elk River 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.
Aerial Photo Interpretation
Sonestroo Natural Resources staff plotted 2003 FSA true-color low altitude aerial
photographs for each section (square mile) of land within the City of Elk River's base
maps. These were printed at a scale of 1"=300'. Available electronic data layers such
as the National Wetlands Inventory, the Sherburne County Soil Survey, geopolitical
boundaries; parcel boundaries, transportation information, and DNR Natural Heritage
(MCSS) data were also printed on these plotted photos to aid in remote interpretation
of land cover. In addition, 2002 MN DNR 1 :15,840 scale, color infrared aerial
photographs were also used as an aid to remotely sense vegetation type and natural
community structure
The boundaries of natural communities and semi-natural areas were delineated on the
plotted aerial photos. The potentia1 natural community boundaries, as well as any
other relevant information were recorded by hand onto these plotted maps.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
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Landowner Notification
Potential natural community locations marked on plotted maps were used to identify
parcels where field visitation by a plant ecologist was desired. Staff from the City of
Elk River sent each of these landowners a letter in the spring of 2004 to respectfully
request permission to visit the natural area(s) on their property. Over 900 letters were
mailed to property owners, 560 self-addressed, stamped postcards were returned.
The returned cards revealed a Jaw percentage of property access compared to the
amount of land available for survey, and thus the amount of data that could be
collected for some natural communities was reduced. This resulted in somewhat less
detailed data than originally desired on aspects of natural areas such as natural
community quality and instances of nonnative plant infestations for areas that could
not be adequately viewed from the edge or at a distance.
This project focused on inventorying natural areas on parcels of 5 acres or greater,
including all natural areas that extend beyond the boundary of those parcels. The
following page shows the project area within Elk River (parcels greater than 5 acres),
as well as those properties where access was granted for field inventory.
Field Inventory
Field inventory work and land cover classification took place in summer and fall 2004.
Where private landowners declined entry to their property, viewing an area from a
distance, or less desirably, remote interpretation was relied upon. During field review
of areas, a 5-digit MLCCS code was assigned to any particular area/polygon. In
addition, other pertinent data was recorded including notations using MLCCS Modifiers
and Field Check Levels (see below).
The field survey also included identification of dominant plant species within a given
natural community. Intensity of inventory effort was related to the overall quality of an
area. In general, good quality natural communities were more thoroughly inventoried
and more extensive searches conducted for less frequently occurring or State-listed
plant species. The field inventory emphasized gathering data on the composition,
structure and function of natural communities, including disturbance indicators such as
exotic species and erosion. This information provides a solid starting point for
assessing the current condition of the community and can be used to develop
management recommendations.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
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City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
9
Land Cover Classification
MLCCS Background
MLCCS, Version 5.4 was used to classify land cover within the city. A brief
explanation of the method and its application to this project is provided below. The
complete 273 page MLCCS Manual can be viewed/downloaded on the MN ONR web
site at the following address: htlP//wwwdnr.state.mn.us/mlccs/index.html .
MLCCS has a five-level hierarchical system of land cover codes to describe natural
semi-natural, and cultural land cover types. Natural land cover types i'nclude areas
such as forests, prairies, wetlands, shrublands, and other similar areas. Semi-natural
areas are those dominated by nonnative plant species, but are not actively
planted/maintained by humans through activities such as mowing/cutting. Cultural
land cover types are areas that can be thought of as developed or substantially
impacted by humans. These typically include paved (impervious) areas, agricultural
fields, pastures and frequently manipulated grasslands, quarries, and others. The Elk
River inventory focused on natural and sem-natural areas for land cover mapping.
Progression through each of the five levels of the system represents an increased
level of detail in land cover classification. In this framework, Level 1 is the least
detailed and Level 5 is the most detailed. For the purposes of this project, all natural
and semi-natural areas within the city were classified to the greatest level of detail
practical (typically, Level 4 or Level 5).
MLCCS Modifier Codes
Several 'classes' of MLCCS modifiers were assessed in the field while conducting the
land cover classification of Elk River. These modifiers were assessed based on the
methodology and definitions provided in the MLCCS training manual. Once assessed,
the modifier values were entered into the GIS database for each land cover polygon.
Below is a brief summary of the most commonly used MLCCS modifiers for this
project.
Natural Community Quality Modifier (M_34x)
The M_34x 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 four general categories. The assessment method
is based on general ecological variables, and is applied in the scJme manner for all
City of Elk River, MN - Natural Resouce Inventory
Bones/roo Natural Resources. September 2004
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natural community types. The following is the description of the M_34x modifier from
the MLCCS training manual:
34X - Modifiers for natural community qualitv rankinq
The natural plant community sites can be given a natural quality ranking, based on the
DNR's Natural Heritage's Element Occurrence Ranking Guidelines' (EOR). See
"Natural Communitv Modifiers" for a discussion of the Element Occurrence Ranking
Guidelines.
Refer to the EOR Guidelines to evaluate the specific natural communities. Non-native,
altered and disturbed communities should only be given a non-native ranking (NN or
NA). Valid codes and general definitions modifier m_34X are:
. A = highest quality natural community, no disturbances and natural processes intact.
Site must be visited entirely or partially to accurately assess its natural quality at this
level (fldJevel = 3 or 4) Modifier code = 341
. B = good quality natural community. Has its natural processes intact, but shows signs
of past human impacts. Low levels of exotics. Site must be visited entirely or partially
to accurately assess its natural quality at this level (fldJevel = 3 or 4). Modifier code =
342
. C = moderate condition natural community with obvious past disturbance but is still
clearly recognizable as a native community. Not dominated by weedy species in any
layer. Minimally, the site must be visited from the edge to accurately assess its natural
quality at this level (fld_level = 2, 3 or 4). Modifier code = 343
. 0 = poor condition of a natural community. Includes some natives, but is dominated
by non-natives and/or is widely disturbed and altered. Herbaceous communities may
be assessed with this ranking from a distance (fld_level = 1) if large masses of
invasive species are present and the entire community is visible. Modifier code = 344
. NA = Native species present in an altered / non-native plant community. This NA
ranking can only be used if the site is field checked from the edge or to a greater
degree (fldJevel 2, 3, or 4), thus confirming the presence of native species within a
non-native community. Modifier code = 345
. NN = Altered / non-native plant community. These semi-natural communities do not
qualify for natural quality ranking. Using NN signifies the site has been field checked
and confirms it is a semi-natural community. Modifier code = 346
Invasive Species Modifiers (M_ 4xx)
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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. These species are important to have information about 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/Estimated Percent Cover for Invasive Species
Cover Class Description
0 Unknown, or if field checked,
plants not observed
1 Observed, unknown quantity
2 1 - 5% Coverage
3 6 - 25% Coverage
4 26 - 50% Coverage
5 51 - 75% Coverage
6 76 - 100% Coverage
The following is a list of invasive plant species modifier numbers. Where these may
have been encountered, they were recorded for aerial coverage within land cover
polygons:
400 - Overgrown prairie/savanna
401 - Overgrown woodland
402 - Purple loosestrife
403 - Eurasion watermilfoil
404 - Curly-leafed pondweed
405 - Flowering rush
406 - Narrow-leaf cattail
407 - Crown vetch
408 - Common and glossy buckthorn
409 - Leafy spurge
410 - Tartarian honey suckle
411 - Garlic mustard
412 - Reed canary grass
413 - Smooth brome
414 - Spotted knapweed
. http://files.dnrstate.mn.us!ecoloqical servlces!nhnrp/eoranks2001.pdfp/eoranks2001.pdf
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
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415 - Exotic thistle
416 - Siberian elm
417 - Ph rag mites
418 - Grecian foxglove
419 - Amur maple
420 - Black locust
421 - Absinthe sage
422 - Dames rocket
499 - Other
Field-check Level
A field-check level modifier was assigned to appropriate areas. The field-check level
indicates the degree to which an individual polygon was checked in the field during the
land cover assessment. Where access permitted, most of the natural area polygons
within this project were visited wholly/partially or viewed from edge. The following is a
list of field check modifier values and their associated description:
. 0 = site not visited
. 1 = viewed the site from a distance
Was not able to walk to the site, but was able to discern the dominant vegetation.
Masses of invasive species may be visible, and thus were recorded (buckthorn, reed
canary grass, crown vetch, etc). Depending on the perceived quantity of invasive
species, a natural quality ranking of D mayor may not be discernable.
. 2 = visited the edge of the site
Walked or drove to the edge of the site, and was able to inventory some invasive
species and speculate on its natural quality. Depending on the perceived quantity of
invasive species, a natural quality ranking of C or D mayor may not be discernable.
. 3 = visited part of the site
walked into the site and was able to confidently inventory most invasive species
present and assess its natural quality - A, B, C or D. Wetlands that are inventoried
from the edges in several places should be given this field check level.
. 4 = visited the entire site
Was able to inventory all invasive species present and assess the site's natural quality
- A, B, C or D.
Other Modifier Codes that were applied, where possible'
. 247 - Trails
. 6XX series - Forestry modifiers
. 72X series - Water modifiers, Built features
. 73X series - Water modifiers, Wetland features
. 74X series - Water modifiers, Stream features
City of Elk River, MN - Natural Resouce Inventory
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. 75X series - Water modifiers, Spring feature
Search for Rare Plant Species
Where natural areas occur, particularly those of better quality, there is the potential for
the occurrence of rare species. Recognizing this, the plant ecologists from Bonestroo
who conducted field inventory work made an effort to search habitats that had a high
likelihood of supporting rare plants.
It is also important to note that although plant ecologists searched areas they had
access to that appeared likely to host rare plants, limited property access, and one-
time visit to only a fraction of natural areas in the city means that some rare plant
populations have likely gone undocumented.
Below is a list organized by habitat type of potential rare plant species that were not
seen during the inventory, but are thought to have the potential to occur within the
remaining plant community remnants in the city.
It is important to note that while this list is provided as a reference, it is not all-inclusive
of rare species that have the potential to be encountered in the city. Likewise, some
rarelhighly uncommon plants tend to be found in special kinds of transitional habitats
that may appear to be disturbed. For instance, lily-leaved twayblade orchid tends to
be found in dry woodland edges that have been recently colonized by brush, and may
have formerly been old fields dominated by non-native, cool season pasture grasses.
Those species that are rare, but capable of colonizing select disturbed areas should
also be taken into account when considering whether an additional search is
warranted. We recommend that an experienced plant ecologist be consulted when
considering whether an additional search is warranted in natural/semi-natural areas'
threatened by development.
Oak Forest:
Common Name
Handsome sedge
Plantain-leaved sedge
Big tick-trefoil
Stemless tick-trefoil
Goldie's fern
One-flowered broomrape
Scientific Name
Carex formosa
Carex plantaginea
Oesmodium cuspidatum
Oesmodium nudiflorum
Oryopteris go/diana
Orobanche unif/ora
Minnesota Status
Endangered
Endangered
Special Concern
Special Concern
Special Concern
Special Concern
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
14
Wild Panax
Oak Savanna and Prairie:
Common Name
Old field toadflax
Field sedge
Hill's thistle
Long-bearded hawkweed
Panax quinquefolia
Scientific Name
Linaria canadensis
Carex conoidea
Cirsium hillii
Hieracium longipilum
Wet Meadow:
Common Name Scientific Name
Marginated rush Juncus marginatus
Small white lady's slipper Cypripedium candidum
Club-spur orchid Platanthera clavel/ata
Cross-leaved milkwort Polygala cruciata
Tall nut rush Scleria triglomerata
Lance leaved violet Viola lanceolata
Twisted yellow-eyed grass Xyris torta
Rich and Poor Fen:
Common Name
Water willow
Mixed Emergent Marsh:
Common Name
Water willow
Walter's barnyard grass
Cattail Marsh:
Common Name
Water willow
Lowland Hardwood Forest:
Common Name
Handsome sedge
Snow trillium
Tamarack Swamp:
Common Name
Water willow
Club spur orchid
Ram's head lady slipper
Scientific Name
Oecodon verticil/atus
Scientific Name
Oecodon verticil/atus
Echinochloa walteri
Scientific Name
Oecodon verticillatus
Scientific Name
Carex formosa
Tril/ium nivale
Scientific Name
Oecodon verticil/atus
Platanthera clavel/ata
Cypripedium arietinum
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
Special Concern
Minnesota Status
Non-listed, but tracked
Non-listed, but tracked
Special Concern
Non-listed, but tracked
Minnesota Status
Special Concern
Special Concern
Endangered
Endangered
Endangered
Threatened
Endangered
Minnesota Status
Special Concern
Minnesota Status
Special Concern
Tracked by DNR (Non-listed)
Minnesota Status
Special Concern
Minnesota Status
Endangered
Special Concern
Minnesota Status
Special Concern
Special Concern
Threatened
15
Land Cover Classification Results
A total of 15,326 acres of natural and semi-natural areas were mapped for this project
in 1,413 individual polygons. These represent a variety of distinct natural and semi-
natural community types including forest, woodland, shrubland, herbaceous wetlands,
and grasslands, as well as areas of open water (lakes and ponds). No cultural areas
were mapped for this project (i.e. paved, developed, cropped, residential areas).
Below is a summary of MLCCS cover types for this project:
Planted Cover (20,000) (28 acres, 0.2%) This cover type is normally not considered
to be a natural area type, but some were included here due to native species being
present. This area represents a site within the City where pines have been planted
onto dry prairie
Forest (30,000s) represents an important part of Elk River's natural areas land cover,
comprising 5,718 acres (42.0%) of the city's land cover. Native dominated/remnant
forest cover types (30000's) within the city included native community remnants such
as dry 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.
Woodlands (40,000s) comprise 1,458 acres (10.7%) of the city's land cover.
Although some acreage is degraded deciduous woodland dominated by elm, box
elder, ash, and cottonwood, or less commonly red cedar woodland and second growth
oak woodland/brushland, much is oak woodland with varying amounts of brush
encroachment.
Shrublands (50,000's) comprised 373 acres (2.7%) of the land cover. The majority of
this cover type was associated with wetland systems and also commonly had
significant presence of nonnative species, such as reed canary grass.
Herbaceous vegetation types (60000's) were most prevalent with a total of 5,101
acres (37.5%). This cover type series includes natural communities such as wet
meadows, cattail marshes, rich fens, mixed emergent marshes, prairies, as well as
non-native dominated cover types such as reed-canary grass dominated wetlands,
agricultural old-fields, and other fallow land.
City of Elk River. MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
16
Open water habitats (90000'S) represents 926 acres (6,8%) of the land cover in the
city, The Mississippi River is the defining water open water feature within the City,
Important lakes include the impounded Lake Orono (Elk River) and Twin Lakes, All of
these water bodies are important resources for the city and should be afforded
appropriate safeguards to maintain or improve their quality,
The figure on the following depicts land cover for the City of Elk River at MLCCS -
Level 1. A digital version of the land cover data has been provided with the Final
Report to City staff in a format that can be used within a geographic information
system (GIS) such as ArcView. Summaries for cover type data are also included as
Appendix B at the back of this report.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
17
MLCCS Level 1 Summary
Elk River Natural Resources Inventory & MLCCS
~Paroelbound.aries
020000. Planted vegetation
~.'''' 30000. Forest
~ 40000 - Woodl.and
Dr50000.Shlubland +
D 60000. Herbaceous
D 90000 - Open Water Habitats:
C Elk RiveT Boutldary
j\/Road!:
~""'"
'. .
." f. "1
.E]rt\',;~c~';
J,'lJF..(It'Io:-nrQO
......1Ia,~"
U=~
''''_'''nI'M''''
1:',( +a,:'.1 +O::O~ loo'al::"~'.'I,(~.~':';',+O.:r;I~'; .~~ Le'!oL l_al"I"
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
18
Natural Resource Inventory Results
1,413 individual natural communities were documented, covering a total of 15,326
acres. These remnants represent a variety of distinct natural community types
including forest, woodland, shrublan<;f, herbaceous wetlands, and grasslands, as well
as areas of open water (lakes and ponds). The following pages include a summary of
the major natural community types encountered in the City, with general descriptions.
It is important to note that there are numerous other natural community types that
occur less frequently in the city. Descriptions for these community types can be found
in the MLCCS User Manual. The complete 273 page MLCCS Manual can be
viewed/downloaded on the MN DNR web site at the following address:
htto://www.dnr.state.mn.lIs/mlccs/index.htm!.
NOTE: A figure summarizing the location of natural areas identified can be
found on the plotted map that accompanies this report. Site-specific field
descriptions of natural areas can be found in Appendix A, shown on the large
map.
Forest (Upland)
Oak Forest (All subtypes)
(MLCCS Code 32110, 32111, 32112, 32113/3,709 Total Acres)
Within Elk River, 229 oak forest remnants were
documented totaling 3,709 acres. The most
common of these was oak forest of unspecified
subtype (109 occurrences totaling 1,175 acres).
Other oak forests include Red maple subtype (1
occurrence of 14 acres), mesic oak forest (16
occurrences totaling 363 acres), and dry oak
forest (109 occurrence of 2,156 acres).
Northern red oaks (Quercus rubra), 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. Mesic stands
most likely were always forest, rather than
woodland or savanna. They have tall (> 20
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
Oak Forest at William O'Brien State
Park, Washington County, MN
J&
meters), straight, single-stemmed trees that lack spreading lower branches.
Commonly, mesic fire-sensitive 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, big-toothed aspen (Populus
grandidentata), and butternut.
Dry oak forest tends to have pin oak Quercus ellipsoir;Jalis, bur oak Q. macrocarpa,
and white oak Q. alba more common as canopy trees. As well, the subcanopy of dry
oak forests in Elk River commonly support red maple Acer rub rum.
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 maple-basswood
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. In much of Minnesota,
including Elk River, drier stands are more common, in part because relative to the
mesic forests they occur on sites with soils less suitable for cultivation.
Forests (Lowland)
Tamarack Swamps (MLCCS Codes 31210, 31213/306 Total Acres)
A total of 16 tamarack swamps
were documented within Elk River.
It should be noted that the quality
of these forests and management
issues associated with them was
mostly either undeterminable or
noted from a distance and/or aerial
photo interpretation due to issues
with property access.
Tamarack Swamp MN ONR - Big Bog State
Recreation Area
. City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
20
Some of the Tamarack swamps within the city tend to be fragmented by
fences/differing past land use, disturbed by excavation or ditching, and have invasive
~ .
species such as cattails (Typha spp.), reed canary grass (Pha/aris arundinacea), and
purple loosestrife (Lythrum sallearia) present. However there are also some Tamarack
communities that appear to be of good or very good quality, particularly in the north
half of the city. Despite this, City of Elk River 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 specie-s or is mixed with black spruce, paper birch, yellow birch, white pine,
black ash, American elm, or red maple. The sedge Carex strieta is common under
relatively open stands of tamarack; cyperus-like sedge (Carex pseudo-eyperus) 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 shade-intolerant 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 pumi/a), several sedge species
(Carex leptalea, C. paupercula, C. tenuiflora), swamp loosestrife (Lysimaehia
thyrsiflora), marsh cinquefoil (Potentilla palustris), willow (Salix pedieellaris), and
northern white cedar (Thuja oeeidentalis)].
Lowland Hardwood Forest (MLCCS Code 32220 1417 Total Acres)
A total of 44 lowland hardwood forests were documented within the city. Lowland
hardwood forest is a wet-mesic forest that is present throughout Minnesota It is
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
21
transitional between the terrestrial and palustrine systems, occurring on sites with
seasonally high water tables (within the tree-rooting zone) but do not flood regularly
and have mineral rather than peat soils. In accordance 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 Codes 32210, 32211/350 Total Acres)
A total of 23 floodplain forests were
documented within the city. 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
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
Floodplain forest, Buffalo Co. WI (WI DNR)
22
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 southem 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 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
Oak Woodland/Srushland (MLCCS Code 42120 11,115 Total Acres)
A total of 98 occurrences of oak woodland/brushland were documented within the city.
These were generally low to moderate quality due to encroachment by brush, lack of
appropriate levels of grazing, the
absence of periodic fires, and
other factors. Although some
higher quality sites were noted
as well. Oak woodlands
observed ranged in size from
0.5 to 25.9 acres in size.
Oak woodland-brushland occurs
on dry to mesic site~ throughout
I
\~.
!t~:_~.~;
Oak Woodland-brushland in winter, Cottage Grove, MN
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
23
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 (Comus 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 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 well-developed tree canopy. There are four geographic
sections of oak woodland-brush land in Minnesota. These sections may be modified in
the future as more information becomes available.
In southeastern and central Minnesota, oak woodland-brush land 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,
City of Elk River, MN - Natural Resouce Inventory
BOllestroo Natural Resources, September 2004
24
basswoods, and black cherries may also occur in the canopy. White oaks (Quercus
alba) are rare and aspens (Popu/us tremu/oides) 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 /27 Total Acres)
Eight mesic oak savannas were found within the City of Elk River.
The characteristic trees of mesic oak savanna are bur oaks (Quercus macrocarpa)
and to a lesser extent northern pin oaks (Quercus ellipsaidalis). 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, open-grown trees
were probably also
common.
The distribution of trees
ranged from evenly spaced
to strongly clumped. Shrub
cover, likewise, was
probably quite variable. Oak savanna in Washington County, MN
The shrub layer included chokecherries (Prunus virginiana), low juneberries
(Amelanchier humilis), gray-bark dogwoods (Comus racemasa), wolfberries
(Symphoricarpos accidentalis), and on lighter soils, prairie willows (Salix humilis), New
Jersey tea (Ceanothus americanus), and American hazelnuts (Cory/us americana).
Leadplant (Amorpha canescens) was always present. The herbaceous vegetation
was dominated by species typical of mesic prairie, but herbs typical of oak woodland
City 01 Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
25
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 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 sun-loving 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.
Dry Oak Savanna - (MLCCS Codes 62120, 62122/62 Total Acres)
A total of nine dry oak savanna polygons were documented in the city. Three
occurrences were dry oak savanna-barrens subtype and six dry oak savanna-subtype
unspecified. Dry Oak Savanna occurs on the same kinds of landforms as Dry Prairie,
except for bedrock bluffs. The
barrens subtype of dry savanna
occurs on the same kinds of sand
deposits as the Barrens Subtype of
Dry Prairie. On dune blankets~ it
tends to be favored over prairie in
areas of sharper relief. Bur oaks
are generally the prevalent trees,
but northern pin oaks are also
common.
Small, gnarly, open-grown trees are
most common, although in moister
City of Elk River, MN - Natural Resouce Inver
Bonestroo Natural Resources, September 2004
Dry oak savanna/barrens prairie in Section 18, Elk River
spots, or in heavier soils, larger trees are sometimes more common. Trees range in
spacing from sparse and evenly spaced to strongly clumped. The shrub layer is
usually sparse; the most common species in the shrub layer are oaks (in the form of
grubs), chokecherry, American hazel, smooth sumac, prairie willow, bush juniper
(Juniperus communis) and New Jersey tea (Ceanothus americanus) are usually
present. A rare shrub, creeping juniper (Juniperus horizonta/is) is present at a few
locations in Elk River. The herbaceous vegetation present in open areas is similar to
that of the Barrens Subtype of Dry Prairie.
The presence of savanna rather than prairie indicates a lower fire frequency or
intensity (or both) than in prairie. Dry Oak Savanna requires less frequent fire than
Mesic Savanna for maintenance. However, in the complete absence of fire, woodland
will eventually replace Dry Oak Savanna. Grazing and browsing animals may also
have had a role in the maintenance of Dry Oak Savanna. Because Dry Oak Savanna
occurs on sites that are not as suitable for cultivation as Mesic Savanna sites, and
because succession in the absence of fire is not as rapid, more examples remain of
Dry Oak Savanna than of Mesic Oak Savanna.
Shrublands
. Wet Meadow - Shrub Subtype (MLCCS Code 52420 I 45 Total Acres)
Eight wet meadow shrub subtypes were documented withiri the city. 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 Comus sericea, Salix bebbiana, Sa/Ix
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. /acustris, C. lanuginosa, C. rostrata, and C. stricta), or
grasses such as Canada blue joint (Ca/amagrostis canadensis) and reedgrass
(Ca/amagrostis stricta). Forbs include swamp milkweed (Asc/epias incamata), lance-
leaved aster (Aster lanceo/atus), New England aster (A. novae-ang/iae), swamp aster
(A. puniceus), turtlehead (Chelone glabra), joe-pye weed (Eupatorium maculatum),
and common mint (Mentha arvensis).
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
27
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 >1 m tall. The leaves of typical grasses and sedges within this community are
>3mm wide (such as Canada blue joint (CaJamagrostis canadensis), lake sedge
(Carex lacustris), and tussock sedge (C. stricta)).
Willow Swamp (MLCCS Code 52430 / 10 Total Acres)
Three records of willow swamp were documented within Elk River. Willow swamp is a
minerotrophic wetland with a canopy of medium to tall (>1 m) 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. 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 (The/ypteris
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 (A/nus
rugosa), holly (l/ex 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 >1 m tall.
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Herbaceous Wetlands
Cattail Marsh (MLCCS Codes 61510, 61610, 61710, 61810/347 Total Acres)
Fifty-two cattail marshes were documented within the City of Elk River. For the
purposes of this project, cattails marshes do not include monotypic (i.e. single species)
stands of the nonnative narrow-leaf cattail with very low species diversity. Wetlands
within the city of City of Elk River comprised primarily of narrow-leaf cattail (Typha
angustifolia) 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 numerous medium to small disturbed basins containing a monotype or
combination of invasive species.
Cattail marsh is an emergent marsh
dominated by cattails (including Typha
latifolia, less frequently T. angustifolia,
and very often their hybrids T. glauca).
Cattail marshes 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 muck-bottom
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 fem (Thelypteris palustris), swamp milkweed (Asclepias incamata),
jewel-weed (Impatiens capensis), broad-leaved arrowhead (Sagittaria latifolia), mad-
dog skullcap (Scutellaria lateriflora), marsh skullcap (Scutellaria galericulata), and blue
vervain (Verbena hastata).
Wet Meadow (MLCCS Code 61420, 61540/268 Total Acres)
Thirty-five wet meadows were encountered during the survey of Elk River. 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. haydenil) or grasses (e.g., Calamagrostis canadensis, Cc inexpansa).
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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.
Poor fen (MLCCS Codes 61450, 61451/30 Total Acres)
Eleven occurrences of poor fen were noted during this survey, most of which are in the
northem part of the city. Those which were inventoried were all of good to very good
quality.
Poor Fen is most common in the conifer-hardwood forest zone, with scattered
occurrences in the deciduous forest-woodland zone. The ground cover of the
community is typically dominated by wiregrass sedge (Carex lasiocarpa) or few-
seeded sedge (C. oligosperma). Mud sedge (C. lirnosa), creeping sedge (C.
chordorrhiza), beaked-sedge (Rhynchospora alba), tufted club-rush (Scirpus
cespitosus), scheuchzeria (Scheuchzeria palustris), and ericaceous shrubs are
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present in most Poor Fens as associates of the dominant sedges. Poor Fens have at
least 50% cover by sphagnum mosses. and up to 70% cover by shrubs and small
trees, most commonly bog birches and stunted tamaracks.
Poor Fen occurs on deep peat (>1.0m)
that receives minimal nutrient-rich run-off
from surrounding uplands. In
Minnesota's large patterned peatlands,
Poor Fen often is present on sites with
water infiltration from adjacent raised
bogs. Less frequently,
Poor Fen occurs in the interiors of small
basins that are relatively isolated from
run-off. This is the case for fens in Elk
River. The surface water of Poor Fen is Poor Fen example - Eden Prairie, MN
slightly acidic (pH 4.1 - 5.9) and nutrient
poor ([Ca2+] <13 mg/I). Poor Fen is transitional between Rich Fen and Open Bog and
commonly grades into these communities on the landscape.
There are four subtypes of Poor Fen, a Sedge Subtype, a Shrub Subtype, a Scrub
Tamarack Subtype, and a Patterned Subtype.
Kev-based definition: A saturated wetland on peat >0.5m deep where grasses and
sedges, such as Carex lasiocarpa, and C. chordorrhiza, are mostly <3mm wide and
there is <50% cover by shrubs, including dwarf-shrubs. The community does not
occur on the floating mat at the edge of a shallow lake and lacks the complex
patterned topography of strings and flarks. The following species are NOT common:
Carex livida, C. buxbaumii, Pedicularis lanceolata, Eleocharis compressa,
Muhlenbergia glomerata, and Lobelia kalmii.
The National Veqetation Classification Svstem description of a more narrowlv defined
community is qiven here as well: This graminoid poor fen community is found in the
Great Lakes region of the United States and Canada, as well as elsewhere in central
Canada, ranging from Ontario to Manitoba, south to Iowa, and east to Illinois. Stands
are found in peatlands with low exposure to mineral-rich groundwater, including basin
fens, shores above the level of seasonal flooding and larger peatlands. Water
hydrology is saturated, and surface water is slightly acidic and nutrient poor. The
vegetation is dominated by graminoids, with up to 25 percent shrub cover, and
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scattered trees. The dominant graminoid is Carex lasiocarpa, and typical associates
include Carex chordorrhiza, Carex limosa, Carex o/igosperma, Rhynchospora alba,
Scirpus cespitosus, and Scheuchzeria palustris. Forbs include Arethusa bulbosa,
Aster borealis, Calopogon tuberosus, Pogonia ophioglossoides, Sarracenia purpurea,
Solidago u/iginosa. The low-shrub layer contains Andromeda polifolia, Betula pumila,
Chamaedaphne calyculata, Larix laricina, Salix discolor, Salix pedicel/aris, and
Vaccinium oxycoccos. The moss layer is virtually continuous, and is dominated by
Sphagnum capillifolium, Sphagnum fuscum, and Sphagnum magellanicum. Diagnostic
features include the dominance of graminoids, particularly Carex lasiocarpa, the
almost continuous layer of Sphagnum peat, and few minerotrophic indicators.
Rich Fen (MLCCS Code 61460, 61461, and 61462 I Total Acres)
Within the city, nine rich fens were documented, two of these were floating-mat
subtypes found along the margins of small lakes.
The ground layer of rich fens is dominated by wiregrass sedge (Carex /asiocarpa),
brown sedge (Carex buxbaumii), livid sedge (Carex /ivida), bluejoint grass
Calamagrostis neg/ecta, 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 its higher species diversity and by the more frequent occurrence and
greater abundance of minerotrophic indicator species, including livid sedge (Carex
/ivida), brown sedge (C. buxbaumii), swamp lousewort (Pedicularis lanceolata), spike-
rush (Eleocharis compressa), marsh muhly (Muh/enbergia glomerata), and Kalm's
lobelia (Lobe/ia ka/mii).
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).
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The sedge. subtype rich fen does not occur on the floating mat at the edge of a shallow
lake and lacks the complex patterned topography of strings and flarks. Rich fen -
floating-mat subtype occurs on the floating mat at the edge of a shallow lake, In both
community types there is no discharge of calcareous groundwater, and the following
species are often common: Carex livida, C. buxbaumii, Pedicu/aris lanceo/ata,
E/eocharis compressa, Muhlenbergia glomerata, and Lobe/ia ka/mii.
. Mixed Emergent Marsh (MLCCS Code 61520, 61620 /205 Total Acres)
Thirteen mixed emergent marshes were documented within the city. Within most of
the mixed emergent marsh remnants in the study area, reed canary grass (Pha/aris
arundinacea) is a common invasive species. This is especially true adjacent to
agricultural lands that have high sediment and nutrient load in their runoff.
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 aeutus), river bulrush (Scirpus fluviatilis),
softstem bulrush (Scirpus va/idus), Scirpus americanus, and Scirpus heterochaetus.
Common reed grass (Phragmites australis), spike rushes (E/eocharis 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 /atifolia) 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 /38 Total acres)
One remnant mesic prairie was encountered within the city, in Gagnes Park Others
can be characterized as prairie plantings that were assigned the MLCCS code of
mesic prairie as a result of the MLCCS dichotomous key structure.
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It is important to note that plantings of prairie species, typically referred to as "prairie
restorations" are invariably less species rich than native prairie remnants, mimic only a
small fraction of the function of a remnant prairie, and are ohen fraught with exotic
weed species such as smooth brome (Bromus inermis) and Kentucky blue grass (Poa
pratensis) among others. These prairie plantings are typically dominated by a handful
of native grasses, including big bluestem (Andropogon gerardil), switchgrass (Panicum
virgatum), and Indian grass (Sorghastrum nutans), with little blue stem (Schizachyrium
scoparium) seldom used.
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 gerardil), 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 prairie cord grass (Spartina pectinata) and
to a lesser degree switch grass (Panicum virgatum) more 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.
Hayden Prairie State Preserve, Howard County, Iowa shows an example
of a mesic prairie similar to what may have historically occurred in the
study area. (photo: Paul Bockenstedt 1990)
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,
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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 morainal 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 species-composition also varies locally with soil moisture. There is
greater regional variation among forbs than among grasses. Common forb species
include purple prairie-clover (Da/ea 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 fIodmanii),
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 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
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The soils in mesic prairie are predominantly mollisols with thick, dark mineral suriace
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.
Dry Prairie - (MLCCS Code 61210, 61211, 61213/322 Total Acres)
There were 40 occurences of dry prairie documented in Elk River. Of these, 23 were
of unspecified subtype, 16 were Barrens Subtype, and one along Lake Orono was
considered sand-gravel subtype. Because the barrens subtype is the most common in
Elk River, its description is provided below.
The Barrens Subtype of Dry Prairie occurs
primarily on dry to dry-mesic sands on
outwash plains, old dune blankets, and
alluvial deposits along rivers and streams.
The low nutrient levels, low levels of organic
matter, and poor water-retaining capacity of
the deep sands presumably are the major
determinants of the species composition and
structure of Barrens Prairie. The vegetation
is generally sparser than in other Dry Prairie
subtypes (often with less than 50% cover),
but is fairly rich floristically. The major
graminoid species in the barrens subtype in
general include all of the common
graminoids for Dry Prairies, excluding side-
oats grama. Other graminoids characteristic
of the Barrens Subtype are sand dropseed (Sporobo/us cryptandrus), sand reedgrass
(Ca/amovilfa /ongifo/ia), hairy grama (Boute/oua hirsuta), blue grama (Boute/oua
gracilis), and several sedges, notably Carex toenea and Cyperus schweinitzii.
Among the more distinctive forbs that occur in this subtype are prairie sagewort
(Artemisia trigida), plantain-leaved pussytoes (Antennaria p/antaginito/ia),
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Barrens prairie in Section 18 of Elk River
36
large-flowered beard-tongue (Penstemon grandiflorus), hairy puccoon (Lithospermum
caroliniense), and silky prairie-clover (Petalostemum vi/losum). Prairie willow (Sa/ix
humi/is) is generally a common low shrub in this subtype. Several plant species
characteristic of the Barrens Subtype (for example, the State-listed false heather
(Hudsonia tomentosa)) are restricted to local disturbances such as active blowouts or
slipfaces.
The Barrens Subtype often occurs as inclusions in areas of Dry Oak Savanna
or Oak Woodland. The Barrens Subtype grades into Mesic Prairie or even into Wet
Prairie in low areas or where sand grades into richer soils. In Elk River, occurrences
are of Barrens prairie are found on outwash along the Mississippi River and on the
Anoka Sand Plain.
Other Plant Assemblages (MLCCS Semi-natural Community Types)
There are a number of plant assemblages in the study area that do not have sufficient
species composition, three-dimensional structure, or overall function to be considered
natural communities as described in Minnesota's Native Vegetation. A Key to Natural
Communities (MN DNR 1993). These communities were assigned community names
according to the protocols of the Minnesota Land Cover Classification System. These
were included in this as part of the inventory as a way of creating a more complete
picture for the permanent habitats within the city. Although they are not natural areas
by definition, they possess one or several characteristics that contribute to overall
function of natural areas at a landscape-level due to proximity to other natural areas,
good restoration potential back to natural area, or they may represent the only large
block of habitat in the area, or others.
The names assigned to these MLCCS communities are standardized, descriptive in
nature, and give an indication of the structure of an area, as well as the water regime.
Some examples of common semi-natural MLCCS community type names included in
this report are:
. Altered/Nonnative Deciduous Forest
MLCCS Code 32170
This upland deciduous forest is not dominated b)l oaks, aspens, balsam
poplars, paper birches, yellow birches, sugar maples, or basswoods
Boxelder, green ash, and cottonwood are typical canopy dominants,
sometimes together and sometimes singly. Elms are common associates.
Hackberries, aspens, oaks, and basswoods may also be present. The
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shrub layer is often dominated by buckthorn and Tartarian honeysuckle, but
gooseberries and elderberries can also be common. The ground layer is
also dominated by species tolerant of disturbances, including white
snakeroot, motherwort, and garlic mustard. Occasionally, when higher
quality forests are nearby, the .understory can be more diverse.
Disturbed Deciduous Woodland
MLCCS Code 42130
These upland areas have 10-70% tree cover, of which <25% is by conifers.
Aspens comprise <70% of tree cover, and oaks comprise <30%.
Herbaceous species comprise <30% of the non-tree cover. Boxelder, green
ash, and cottonwood are typical canopy dominants, sometimes together and
sometimes singly. Elms are common associates. Hackberries, aspens,
oaks, and basswoods may also be present. The shrub layer is often
dominated by buckthorn and Tartarian honeysuckle, but sumacs,
gooseberries and elderberries can also be common. The ground layer is
also dominated by species tolerant of disturbances, including white
snakeroot, motherwort, and garlic mustard. Occasionally, when higher
quality forests are nearby, the understory can be more diverse.
Medium-tall grass nonnative dominated grassland
MLCCS Code 61220
These are often plantings of smooth brome grass like those planted for the
Conservation Reserve Program in the 1980's, or some other nonnative
pasture grass. This upland grassland is generally <1 m tall, with <10% tree
cover and <50% shrub cover, and is dominated by non-native species, such
as brome, Kentucky bluegrass, reed canary grass, and spotted knapweed.
Saturated to Seasonally flooded nonnative dominated graminoid
vegetation
MLCCS Codes 61480, 61530, 61630
These wetland areas are typically disturbed by one of several human
activities such as draining and/or planting of nonnative grasses, as well as
grazing. These areas typically occur in the same settings that wet meadows
or shallow marshes would occur and tend to be dominated by the
nonnatives reed canary grass and/or narrow-leaf cattail).
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Grassland with sparse deciduous trees - nonnative dominated
MLCCS Codes 62140,
These areas typically occur as former oak savannas where the ground cover
was planted to nonnative pasture grasses, or more commonly abandoned
agricultural fields planted to perennial nonnative grasses and later colonized
by pioneer tree species. This upland vegetation has 10-70% cover by trees
(of which <25% is conifer), where >30% of non-tree cover is herbaceous
and dominated by non-native species. The ground layer is often dominated
by brome or Kentucky bluegrass. Common shrubs include sumac and
Tartarian honeysuckle. Almost any tree species can be found here, but
elms, cottonwoods, green ashes, boxelders, and bur oaks are common.
It is important to note that while these plant assemblages do not meet the criteria
developed by the MN DNR Natural Heritage Program as remnant natural communities,
they can still provide important habitat for wildlife. They can also be important in the
landscape, providing buffers from developed and intensively farmed areas. In some
cases, such as "Grassland with sparse deciduous trees" areas, there may be
opportunity to easily restore a natural community such as Mesic Oak Savanna that is
exceptionally rare in the Upper Midwest.
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Recommendations
Conceptual Greenways/Open Space Corridors
For the purpose of this report, a greenway is defined as "private/y 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 active or passive recreational trails, active
recreational spaces (such as athletic fields or golf courses), and other public open
spaces that may provide rudimentary ecological functions and values.
As a part of this project, the ecologists at Bonestroo Natural Resources developed a
series of Conceptual Greenways/Corridors shown in the large wall map included with
this report. These corridors were developed with the following guiding elements, listed
in rough order of priority:
. High and Moderate quality natural areas
. Semi-natural areas that occur immediately adjacent to natural areas
. Bodies of water and large wetland complexes
. Natural corridors with natural/semi-natural areas (e.g. streams, drainageways,
ridges)
. Areas that would serve as logical links between natural and semi-natural areas,
particularly those that have potential to be restored to native vegetation
The greenways/corridors shown on the following page are conceptual and broad
stroke in nature. Therefore, we encourage the city staff, along with its citizen
committees and other important stakeholders to undertake a more comprehensive
process of defining and locating potential greenways/corridors. Such a process will
allow for public input, along with technical guidance from experienced staff in the
natural resources field, ensuring long-term acceptance of a final product. During a
greenway/corridor planning process, we suggest that the city consider the following
elements (as a minimum) part of more detailed greenway/corridor planning within the
city:
. Public ownership - where possible, use corridors to connect large publicly
owned open spaces
. Remnant natural areas - provide connectivity between natural areas, especially
those of high quality and/or potential for hosting rare species.
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o Incorporate semi-natural communities --into the greenway system as
corridors to connect and/or buffer the highest quality remaining natural areas
within the city.
o Restore/reconstruct natural areas --to provide connectivity between natural
or semi-natural areas (especially good quality sites) suitable for inclusion with
greenways
o Incorporate water resources and large permanent wetland systems within
the corridor (directly or indirectly). Wetlands, lakes, and streams provide
beneficial wildlife habitat and are not likely suitable for development
o Consider opportunities for recreation and pedestrian movement through
the greenway system. Co-aligning natural and recreation features should be
done in a manner that ensures no negative impacts to sensitive natural areas.
Within the City of Elk River, there are many opportunities to develop a viable
greenways system as the city grows over the next ten to twenty years.
As well, Elk River's water features provide significant wildlife habitat and opportunities
for recreation including the Mississippi River, Lake Orono, and several large wetland
systems. These represent another opportunity to connect and buffer higher quality
natural resources and wildlife habitat corridors within the city.
As the city begins considering more comprehensive greenway/corridor planning, there
are several outside sources of funding/in-kind assistance that is available. One of
these is the MN DNR, which periodically offers funding for planning efforts such as
this. Information regarding the MN DNR's financial assistance programs may be found
at:
htto.//www.dnr.state.mn.us/qrants/index. htm/ .
Zoning and Subdivision Ordinance Review:
Bonestroo ecologists reviewed existing city subdivision requirements and provide
recommendations on how these can be updated.
Overview
The Natural Resources Inventory provides the City with extensive data related to the
location and quality of natural resources in the city. The City can use this information
City of Elk River. MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
41
as a basis for updating its current environmental ordinances, or for developing new
approaches for protecting and enhancing its natural resources.
Future growth, changes in land use, and development of infrastructure can impact the
.health and function of natural communities and natural systems. The City can use its
zoning and subdivision controls to avoid or minimize these impacts, and provide
incentives for developers and landowners to protect or restore natural resources.
The sections that follow offer suggestions for integrating the Natural Resources
Inventory information into the City's zoning and subdivision controls so that the value
of these resources is protected for the long-term as the City develops. Three levels of
options are discussed:
. Updating existing ordinances (
. Adding new ordinances
. Adopting a comprehensive Environmental Conservation Zone approach
Updating Existing Ordinances
The City of Elk River has already adopted a variety of elements in its zoning and
subdivision ordinances that can be used to protect and manage natural resources.
These are a very good base to build upon, and can be updated with the new Natural
Resources Inventory data. The existing environmental ordinances in the City's code
include the following:
. Park Dedication requirements
. Preliminary plat requirements
. Tree protection requirements
. Erosion and sediment management
. Stormwater management
. Open space plat
. Shoreline management
. Floodplain management
Suggestions for updating these existing ordinances based on the NRI include the
following:
City of Elk River, MN - Natural Resouce Invenlory
Bonestroo Natural Resources, September 2004
42
Section 30-327. Park Dedication Requirements
This section could specify that developers are required to dedicate the natural
resource areas identified on the NRI maps as open space or parks if they are located
within the proposed development area to meet park dedication requirements.
If the City does not want to require donation of these lands, it could make NRI status a
"criteria for determining suitability of the land" under Section 30-327(h), and use this
criteria in negotiations for park dedication.
As well, the City may consider adding language to the park dedication ordinance that
specifically states park dedication funds may be used for the purposes of ecological
restoration (restoring native plant communities). Such activities could be considered a
form of park"development". This would allow for necessary active management of
purchased or existing natural areas.
Section 30-353. Data for Preliminary Plat
This section could specify that the proposer include the mapped information from the
Natural Resource Inventory in the "existing conditions" data provided to the City.
This "existing conditions" data yould then be compared to the requirements in Section
30-415, that require that existing trees and native vegetation on the site be preserved
to the maximum extent feasible in the subdivision design.
Section 30-415. Preservation of trees and other veqetation.
This section includes a general statement that "existing healthy trees and native
vegetation on the site shall be preserved to the maximum extent feasible, and shall be
protected by adequate means during construction."
The City could reference the NRI by indicating specifically that "native vegetation
communities identified in the City's Natural Resources InventolY shall be preserved".
This statement is a general one, and does not give a standard for the amount of native
vegetation that should be protected. Some communities have adopted "woodland
protection ordinances" (instead of or in addition to individual tree protection
ordinances) that give performance standards for the proportion of woodland areas that
must be protected from development.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
43
The City could identify such performance standards to this ordinance, and therefore
require that at least a portion of the woodland area be protected. (Ordinances typically
do not require that 100 percent of an area be protected because this may allow for no
use of the property, and would be termed a "taking".)
Inventory staff noted that oak wilt is a problem the affects woodlands in Elk River. The
tree/woodland ordinance could include requirements to protect woodlands during
development, to avoid the spread of oak wilt.
The City could also protect woodlands, prairies, and other natural areas identified in
the NRI by using an overlay zone in its ordinances. These are typically called
Environmental Protection Zones or Environmental Conservation Zones, and this
approach is described in #3, below.
Section 30-417. Drainaqe
The City's Stormwater Management Plan (SWMP) should be reviewed in light of the
NRI results, to determine whether any changes are needed to identify wetlands,
creeks or other areas to be protected from storm water impacts, or other policies that
could be included in the plan to support the findings of the NRI. If a SWMP is not
currently available for developing areas within the City, the City may choose to require
developers to conduct SWMPs prior to approval of development plans, with review of
study results by a qualified water resources engineer (with experience in natural
resources planning).
Section 30-417(2) should be updated to reflect current MPCA requirements for
pretreatment of stormwater before discharge to wetlands.
Based on a review of the plan, the City could decide whether a more comprehensive
Stormwater Ordinance is needed.
Subdivision II. Open Space Preservation Plats
This subdivision of the City Code is a powerful tool for protecting and restoring natural
areas identified in the City's Natural Resource Inventory. Some suggestions to
specifically incorporate the NRI in this section include the following:
. 30-514 (2) and (3)-the sketch plan could be required to show all natural areas
identified in the NRI
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
44
. 30-515 (2)g-this section could include a provision that the "city shall have the
option of requiring that shoreline, areas along streams, and natural areas
identified in the Natural Resources Inventory be included as preserved open
space
. 30-515(7)f-this section could again reference "other environmentally sensitive
areas or natural areas identified on the Natural Resources Inventory."
. Section 30-516(b)-this section could provide an additional density bonus if the
developer agrees to include more than 50% of the area as protected open
space to preserve high quality areas identified on the NRI, or could provide an
additional density bonus if the developer agrees to create and implement a
restoration plan for NRI areas that would benefit from removal of exotic species
or other restoration activities.
New Ordinances
The City of Elk River has a good basic set of environmental ordinances in its code.
Based on the results of the NRI, the City could consider adopting one or more new
ordinances to provide specific protection for wetlands and steep slopes.
Wetland Buffers Ordinance
The NRI identified a number of unique wetland resources of high quality in Elk River.
Many communities in the Metro Area a similar situation have chosen to adopt a
Wetland Buffers Ordinance, based on the inventory of these resources. Buffers (areas
of undisturbed native vegetation) are one of the best ways to protect wetlands as
development occurs in the surrounding area. Buffers help to filter pollutants from
runoff, prevent erosion, provide critical habitat for species that live or breed in
wetlands, and buffer wetlands from disturbance. Buffers may also provide an area for
walking trails, and may be linked together to create natural resource and recreation
corridors.
Buffer sizes are typically related to the quality of the wetland-high quality wetlands
are given wider buffers than low quality wetlands. Sizes may vary from 10 or 20 feet
for low quality wetlands, to 100 feet for the highest quality wetlands The MPCA
provides suggested guidelines for wetland buffer sizes based on wetland types and
quality.
While the Minnesota Wetland Conservation Act provides protection for the wetland
itself, it does not include a requirement for buffers. Instead, the MPCA recommends
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
45
that local communities consider requiring buffers based on the local situation.
Wetlands vary so much within the state that it is often best to have a local inventory
using MnRAM methodology, or similar, and consider local conditions and values as a
basis for this process.
Wetland Buffers Ordinances from other communities in the Twin Cities area are
available for review by the City as examples.
Steep slopes/bluffs ordinance
The NRI has identified areas with steep slopes within Elk River. Given the sandy soils
in much of the area, these slopes may be particularly prone to erosion when disturbed.
The City's code includes a section on erosion and sediment control (Section 30-416)
that addresses requirements for slopes over 10 percent in a general way. The City
may wish to consider a specific steep slopes ordinance for the future. Such
ordinances often include specific requirements for grading, storm water management,
buffers etc., for slopes over 10 or 12 percent, and may prohibit development on very
steep slopes (typically over 25 percent).
Steep Slopes/Bluffs Ordinances from other communities in Minnesota are available for
review by the City as examples.
New Approaches-Environmental Protection Zones Overlay Districts
Overlay districts are commonly used in zoning ordinances to identify special areas and
requirements applied to these areas. The Elk River code includes a Shoreland overlay
district and a Floodplain overlay district, which are included in most city codes.
The Minnesota Environmental Quality Board has suggested an option of using a
broader overlay district called a Sensitive Natural Environment Areas overlay district
for protecting and conserving significant natural resources in the community. This
overlay district can provide protection for a full range of natural community types-
woodlands, prairies, wetlands, and shorelands. It could replace the need for separate
woodland protection and wetland buffer protection elements discussed under #1 and
#2. The areas may also include natural resource corridors or greenways identified in
the community.
City of Elk River, MN - Natural Resauce Inventory
Bonestroo Natural Resources, September 2004
46
The adoption of an environmental protection zone overlay ordinance requires that the
community's resources have been inventoried Elk River's NRI meets this need. In
some cases, two zones are established-Environmental Protection Zones with the
highest level of protection for high quality resources, and Environmental Conservation
Zones for resources of somewhat lower quality that require a lower standards of
protection. The protection zone or zones would be mapped on official city zoning
maps, just as the Shoreland and Floodplain overlay zones are mapped.
The environmental protection zone ordinance then provides requirements or standards
for development within these zones. Such requirements may include the following:
. Setbacks or buffers from the edge of the sensitive area
. Construction management practices to limit disturbance or damage
. Limits to vegetation removal
. Prohibition or limitation of development within the zones by regulating
disturbance, lot sizes, densities, etc.
. Limit to impervious surface coverage
Given the number and diversity of high quality natural areas identified in the City's
Natural Resource Inventory, an overlay ordinance of this type offers a way to provide
protection to this range of resources rather than using multiple ordinances to address
woodlands, wetlands, and other types of natural resources.
The City of Portland, Oregon, has adopted a detailed environmental protection zone
ordinance that provides a good example of such ordinances. In the Portland
ordinance, development is mostly prohibited in the "environmental protection zone",
and environmentally-sensitive development is allowed in the "environmental
conservation zone." Typically, existing development, repairs and maintenance, and
provision of public infrastructure and utilities, public trails, and similar items are
allowed in the protection and conservation zones.
Copies of the Portland ordinance or Minnesota EQB Model Ordinance can serve as
examples of this approach.
Other Tools for Protection and Management of Natural Areas
Ordinances are mainly a regulatory ("stick") approach for protecting and managing
natural resources. Ordinances such as Elk River's Open Space Plat also provide
incentives ("carrots") to natural resources protection. Many communities use a
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
47
combination of carrots and sticks in protecting and managing natural resources. The
regulatory approach assures that some priority resources will be protected, but is
limited by laws that prohibit the "taking" of private property without adequate
compensation. The "carrot" approach may be more politically acceptable in some
cases than the "stick" approach, and may be more viable when potential "taking" is an
issue.
In addition to changes in existing ordinances or adoption of new ordinances, the City
can consider a variety of "carrot" approaches in addition to the Open Space Plat to
encourage city residents to protect the natural resources on their properties, including
the following:
. Provide information and education to homeowners about the special features
on their properties. Many landowners will take great pride in knowing that they
have something special on their land, and will be eager to learn about how best
to manage it.
. Inform property owners about options to donate their land as parks and open
space, or protect it with a conservation easement. For some property owners,
donation of land or easements provide financial and tax benefits.
. Identify grants or other public programs that provide financial or educational
benefits to owners of natural areas
. Work with developers or property owners to encourage design strategies that
protect and improve the quality of resources.
. The DNR Website (http://files.dm.state.mn.us/assistance/landprot.pdf) contains
the resource Land Protection Options, a Handbook for Minnesota Landowners.
This is an outstanding tool to help individual landowners better understand their
options, and also for city staff as a resource to help positively engage interested
property owners.
. Another important resource for private landowners is the publication Beyond the
Suburbs: A Landowner's Guide to Conservation Manaqement. This resource
can also be found on the MN DNR website at:
http://file_s.dm.state.mn.us/forestry/beyond suburbs. pdf
. The City can also continue to set a good example for other landowners by
protecting or restoring natural areas on city-owned properties.
Parcel Evaluation
As part of this project Bonestroo ecologists identified parcels greater than 40 acres in
size that are thought to be suitable for non-standard development design methods
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
48
such as cluster development. This analysis was conducted after the complexity of the
field work, so that data from the NRI could inform the process. This evaluation
focused on sites that contain quality natural areas and have the potential to be
developed. Areas that were considered not to be unsuitable for development had
characteristics such as being completely covered by floodplain/wetlands, previously
permitted for aggregate mining, and city-owned land (parks).
On some of the recommended parcels, property access prevented a field inventory.
These are noted in th'e project data base as recommended for additional field
inventory. Where additional surveys are recommended, they should occur prior to
development, most preferably in advance of submittal of development documents to
the City by the developer. This will allow for the gathering of solid field information to
permit sound decision-making about natural areas, as well as minimizing the cost of
such a process to both the City and developer. The following page shows parcels
identified as suitable for cluster development and other non-standard design methods.
Sites to Consider for Proactive Management/Protection
There are a number of remnant natural areas on city-owned property or that occur on
recreational/historic properties. Based on field observations, we recommend these
areas be (further) managed. This may include the creation of site-specific Natural
Resource Management Plans and/or on-the-ground management. It is also important
to note that these natural areas may be good candidates for grant/foundation funding
to complete these activities, reducing or enhancing the financial resources dedicated
by the City.
City-owned Natural Areas
The City owns a number of properties with moderate to high quality natural areas that
have good restoration potential. Many of these occur in City Parks. Some of the City
Park areas appear to be actively managed, while others are not. Following is a brief
list of City-owned natural areas that support high quality resources, as well as some
recommended next steps for management.
Non-City-owned Historical/Recreation Properties
There are two historical/recreation areas within the City of Elk River that have natural
areas of significance. These include the Elk River Sportsmen Club and the Kelley
Farm. The former is a private club that supports very high quality barrens prairie and
savanna of statewide significance. The Kelley Farm is a property run by the
City of Elk River. MN - Natural Resouce Inventory
Bonestroo Natural Resources. September 2004
49
Minnesota Historical Society that has a significant amount of remnant oak
communities and planted prairie.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
50
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Natural Areas of Hi9tJ and Moderate Quality
The figure on the following page includes High and Moderate Quality natural areas
identified during the inventory. It is important to note that due to lack of access to
some natural areas within the city, not all high quality sites are listed here. We
recommend that appropriate field work be conducted to determine the
quality/composition of larger natural areas not visited for during this project, prior to
any development that may take place.
These are sites of areas that demonstrate one of several significant qualities, including
natural area quality, aesthetics, or other characteristics. We would suggest that these
high quality sites be considered for protection and/or management using appropriate
tools mentioned above, such as ordinances, park dedication, conservation easement,
or similar.
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53
.. Hig,h and Medium Quality
~:,,,,,:'-'
;,,)1 Natural Communities
~ I Elk RJycr 'N .",,,1 RC'D~""1IDVCrllDty & MLCC5
."1 C!::jr~::kIlU,.j l'\
II ~\iiiI I
~ tt.:UUll.c=~Ii';JlltJl' Elk _..:;::
~ : ~' ~Gh I:;I~"I~J +11 Rn't.:r-
II' - al!lJ~ CUil~t1 _
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I':u.:~ 1t:;~::I'I",w;1rm:' ~."'..... 1;1 ::"~:~:
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1~.,..l~h,..,.~,.... "'....,....~.....i~......,...o!;........
1I'JI....;lt~,;1n!II'_~..._\lb,......,. OM'"
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54
General Management Strategies for Natural Communities
General Management Concepts for all Natural Areas
Maintain and Link Together Larger Tracts of Significant Natural Areas
Connectivity and size are both important factors affecting the function of natural areas.
As a general rule, the larger an area is, the greater the diversity of plants and animals
present. Larger natural areas are also more stable and able to withstand the affects of
naturally occurring events such as drought, insects and disease, and windstorms. For
these reasons, the largest high quality natural areas should be given the highest
priority for protection and management. Smaller patches of natural communities and
sites with good restoration potential should then be used to link larger areas together.
Linkages should consider corridors and natural areas outside the County as well as
features within the County.
Maintain Undisturbed Vegetative Buffers Around Natural Areas
A buffer of undisturbed vegetation can provide a variety of benefits. The buffer should
consist of a mixture of trees, shrubs, grasses and forbs, with the mixture dependent on
the specific site. Buffers reduce the impacts of surrounding land uses by stabilizing soil
to prevent erosion, filtering pollutants, providing habitat areas and cover for animals,
and reduce problems related to human activities by blocking noise, glare from lights
and reducing disturbance. Even relatively narrow buffers of undisturbed vegetation can
provide some benefits, but wider buffers will provide additional screening, water
quality, and habitat benefits. Buffers will be most effective if most or all of the
landowners around a natural area cooperate to make a continuous buffer.
Landowners should avoid cutting vegetation, dumping grass clippings or other debris,
and trampling vegetation within buffers. If a path is desired through the buffer, it
should be mown or cut only as wide as is necessary for walking, and located so that it
does not encourage erosion. Likewise, County trail systems should not be located
where they defeat the purpose of natural buffers.
Use Plant Species Native to the Area.
Native trees, shrubs, grasses and forbs can be planted in buffer areas or in degraded
portions of natural areas. Species planted should be indigenous to the region. A good
source of information on indigenous plants is the species list provided in Appendix A of
this report. Plant species should be chosen based on the specific characteristics of
the site including soils, slope, aspect and adjacent natural community types and
quality. If possible, restore the site to replace the original natural community type that
existed before conversion (i.e., prairie, oak forest).
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Control Invasive Exotic Species
Several nonnative species (sometimes called "exotics") are either currently a problem
or have potential to be a problem. These include European buckthorn, Tartarian
honeysuckle, Chinese elm, reed canary grass, smooth brome, Kentucky bluegrass,
leafy spurge, phragmites, Absinthe sage and purple loosestrife. These plants invade
native plant communities and can take over rapidly, eliminating native plants and
leading to a loss of plant diversity and wildlife habitat Often, disturbances from new
road or home site construction serve as a pathway for introduction of these species to
a natural community not yet invaded by exotic species To control invasion by exotics,
minimize disturbance to natural areas and surrounding buffer areas as much as
possible, and avoid planting or providing openings for exotics to invade. Small
populations of exotics may be controlled by hand removal or through direct application
of appropriate herbicides.
Maintain and Place Habitat Structures Where Appropriate
Natural areas provide important habitat for many species of wildlife. Adding wood
duck nest boxes and other types of nesting structures can augment habitat. Retaining
or adding stones, logs, and dead trees in natural areas and buffers provides habitat for
many species of reptiles, amphibians, birds and mammals. While some tree removal
may be necessary for safety or for disease control (e.g., Dutch Elm Disease or Oak
Wilt), dead trees, both standing and down provide habitat for many animals. The
books Lakescaping for Wildlife and Water Quality and Landscaping for Wildlife by
Carroll Henderson are useful guides for improving habitat with plantings and
structures.
Management Recommendations, by Community Type
Following are general management strategies for prairie, savanna, wetland and forest
communities. These management strategies are intended to be generic; therefore
more specific management recommendations may be necessary for individual natural
communities and sites.
Prairie and Savanna Management.
Prior to European settlement the health of prairie and savanna plant communities were
maintained by grazing and fires, both of which probably occurred annually to every few
years on most sites. Some fires occurred naturally, while most were set by Native
Americans. Fires maintained the open structure of prairies by controlling the growth
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and spread of trees and shrubs, removing accumulated plant litter, warming the soil in
spring, and returning nutrients to the soil. With the spread of agriculture and urban
development, fires have been suppressed, leading to the spread of shrubs, trees, and
exotic plants in prairie and savanna communities, and loss of diversity of native
grasses and forbs The activities of large_and small mammals and insects also helped
to maintain prairie communities by spreading seeds, burrowing to loosen soils, and
pollinating prairie grasses and forbs.
In addition to the suppression of fires, prairies and savannas have been degraded by
inappropriate levels of grazing, which reduces forb diversity and encourages the
dominance of clonal plants (such as golden rod) that are unpalatable to livestock.
Other factors responsible for the decline of prairie and savanna communities include,
development, ill-advised tree planting, plowing, and too frequent mowing.
Less than one percent of the prairie and savanna landscapes that once existed In
southeastern Minnesota remain. The goal for managing the remaining remnants
should be to maintain or restore as much of the original diversity as possible, through
re-establishing or mimicking the processes that helped to maintain these plant
communities.
Prairie and savanna management should consider the following actions, as
appropriate for each site:
. Remove exotic species with appropriate methods. Cutting and herbicide treatment
are often most appropriate for tree and shrub. species such as black locust, sumac,
and buckthorn. Repeated herbicide treatments or biological controls may be
needed for other exotic species such as leafy spurge and reed canary grass.
. Remedy disturbance problems where possible, by closing trails where erosion is
occurring, or reduce/rotate grazing to maintain plant populations.
. Use prescribed burns to control cool season grasses and other exotics, remove
accumulated plant litter, encourage recruitment of prairie plants from the seed bed,
and to maintain the health of the prairie for the long term. Burns may be scheduled
annually at first, and reduced to every 3-4 years, depending on amount of litter
available to successfully support a burn. Vary the burn regime over the long-term
to include both fall and spring burns. Burn only a portion of a prairie at anyone
time to conserve insect diversity.
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. If elimination of exotics and prescribed burns over several seasons fails to restore
desired diversity, consider plant community restoration through supplemental
seeding of cut and burned area. Reconstructed prairies and savannas will require
maintenance through infrequent mowing or prescribed burn regimes (burning is
preferred over mowing when possible). Plantings should use native seed from
local sources.
. In general, savannas can be burned less frequently than prairies and droughty
sites burned less frequently than mesic or wet sites. Average burn frequency for
the dry prairies and savannas in Elk River is approximately five years, with a range
of 1-10+ years. In addition, burn frequency should be greater during the first
couple of years if control of nonnative species is a management objective.
. Seasonal timing can have a profound effect on species composition. Current
research information indicates that spring fires, conducted prior to April 15, tend to
favor cool season grasses and summer-blooming forbs. Late spring fires (April 15
_ June 1) tend to favor warm season (usually native) grasses and usually
negatively effect forbs and tree/shrub species. Summer burns would mimic
lightning set fires, and although these did occur, they appear to have been less of
an influence on the presettlement landscape than human-set fires. Current
information indicates that fall fires (after September 15) are most effective at
maintaining a balance between grass and forb species and for controlling brush.
. There is also reason to believe, based on historical records that frequent fall burns
most closely mimic the presettlement burning pattern used by Native Americans in
the tallgrass prairie region of the Upper Midwest.
. Mowing can al.so be used on si\es with adequate accessibility and low risk for site
disturbance. Mowing somewhat mimics the effect of grazing and can give many of
the effects that prescribed burning can. Proper timing and techniques in mowing
can be used to maintain a healthy balance between grasses and forbs.
. Management of native communities, especially prairie, must also consider effects
on the animal populations that are dependent on the community. The influence of
management activities (i.e. burning) are not completely understood on animals
such as butterflies and other invertebrates. To minimize the potential for
devastating impacts on community obligate species and/or fire sensitive species,
management should be carried out so as not to influence the entire area upon
which these species depend on. An example would be not burning an entire prairie
at once; this would leave refugia for the species of concern and allow for potential
recolonization of burned areas.
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. Monitor the effectiveness of management activities, and any changes in plant and
animal species in managed areas Adjust activities as-needed based on
monitoring results. This is a very important part of sound natural resource
management.
Wetland Management
Wetland plant communities are frequently altered or degraded by changes in
hydrologic regimes associated with agricultural or urban development. Farming and
urban development alter the quantity and quality of stormwater entering wetlands by
increasing stormwater runoff and associated sediments and nutrients, and by draining,
filling and ditching wetlands. Agriculture and urban development also alter
groundwater flows, typically diminishing flows through withdrawals for drinking water or
increasing impervious surface areas. Excessive groundwater removal has been
proved to de-water and alter seepage communities and fens.
Goals for wetland plant communities should include maintaining or restoring native
plant communities and diversity by re-establishing or approximating original hydrology
and natural processes. Some communities with variable hydrology, such as cattail
marshes and wet meadows, may be relatively easy to restore or enhance, while more
specialized communities like fens and seepage swamps can be remarkably difficult to
restore if hydrologic conditions have been excessively altered.
Some strategies for enhancing or restoring native plant communities in wetlands
include the following:
. When possible, maintain or restore the natural hydrologic regime, limiting "bounce"
from storm events and maintaining ground water flows. Use infiltration and
vegetation strategies to reduce runoff from the watershed area that drains to the
wetland, or use ponding or other best management practices to moderate storm
flows, and remove sediments and nutrients from stormwater before it enters the
wetland.
. Remove or control invasive exotic species. Repeated herbicide treatments may be
necessary to control reed canary grass and purple loosestrife. Biological controls,
such as weevils, have also shown promise recently in managing purple loosestrife.
Hand removal of exotics by digging may be effective in areas where invasions are
limited. In forested wetlands, buckthorn removal may be required, using cutting
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59
and herbicide treatments Use herbicides that are licensed for use in wetland
areas.
. Establish a vegetative buffer around wetland areas, to filter runoff, slow stormwater
flows, and provide essential upland habitat needed by many species that use both
wetlands and uplands as habitat during their lifecycles. Prohibit cutting, dumping
or other alteration of buffers.
. Plant native wetland and upland plants in constructed wetlands and buffers.
Plantings should use locally native species, and may include aquatic plants,
grasses, forbs, shrubs and trees to provide structural diversity and improve habitat.
. Maintain dead and fallen trees or add nesting structures if desired to improve
wildlife habitat.
. Monitor management efforts and revise strategies as needed to meet goals.
Forest Management
Most of the forest areas in the area have been grazed at varying levels, and in some
cases were logged. Forest communities are often associated with ravines and steep
slopes and are therefore sensitive to the impacts of erosion and sedimentation. In
addition, roads and trails frequently fragment forest communities. All of these activities
encourage invasion by aggressive exotic species-particularly buckthorn and Tartarian
honeysuckle. Fragmentation also reduces the value of the forest community for
wildlife species such as migratory songbirds that require "interior" forest areas that are
well buffered from human disturbances. Following are management strategies for
maintaining and restoring the diversity and health of forest communities:
. Avoid cutting trees in areas containing exotic shrub species. Where cutting trees is
necessary, cut exotic shrubs and treat with a basal application of an appropriate
herbicide. Where developments are proposed within or adjacent to forest areas,
removal and treatment of exotic shrubs could be incorporated into the overall site
preparation process.
. Slow growing and mast-bearing trees such as oak and hickory should be given
particular protection due to their value to wildlife. Other trees through their seeds
or buds also serve as important food sources for wildlife: these include maples,
elms, aspens, basswood and birch.
. Large trees, particularly those containing cavities, should not be removed unless
absolutely necessary. Dead standing and down trees should likewise not be
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removed unless they present a safety hazard. While humans perceive a forest with
dead trees as messy, dead trees are important because they harbor a high
diversity of plants and animals throughout their decomposition cycle. (Note that
sanitation cuts may be necessary where oak wilt or Dutch elm disease is present)
. Encourage removal of weedy and/or exotic tree species such a<; Siberian elm,
boxelder, Russian olive, black locust and eastern red cedar. Plant higher value
native trees and shrubs back into forests following removal.
. Oak forest communities are adapted to fires and can often be improved through
prescribed burns. Prescribed burns will generally increase diversity of grasses and
forbs, encourage oak seedling germination and kill back exotic or invasive shrub
species. Where oak forest communities occur adjacent to prairie and savanna
communities, fires from prescribed burns should be allowed to burn into the oak
forest. Burn more frequently in early years and less frequently as exotic species
are controlled. Include both spring and fall burns in the management regime.
. Maple-basswood and lowland hardwood forest communities are generally not
adapted to fires and should not be burned, or burned very infrequently (every 20+
years).
Oak wilt is of particular concern in Elk River. It is spread by construction activity or
other root/top damage during the growing season. Canopy openings created by oak
wilt can augment invasion by exotic species if not replanted or managed to restore oak
woodlands. Oak trees should not be cut, pruned or injured between April 15 and July
1 of each year. Exposed roots injured by construction activities facilitates the spread
oak wilt infection. A vibratory plow can be used to sever roots along the edge of any
construction area prior to beginning work. This can prevent the transfer of oak wilt
fungus between individuals through grafted roots and allow for regeneration at the
point of cutting. If vibratory plowing is used, the disturbed ground should be restored
to pre-plow contours and planted with an appropriate native seed mix to prevent
invasion by nonnative shrubs and weeds. Tree protection zones should be fenced to
prevent entry or compaction by construction equipment. Soil and construction
materials should not be stored within the tree protection zone, as this can result in
contamination of the tree protection zone and/or other construction sites.
Also, oak wilt may actually be viewed as beneficial in areas that are being restored to
savanna and prairie. as it makes more light available for prairie and savanna plants.
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Glossary of Technical Terms
Acre-Foot Volume of water that would cover an acre of land to a depth of one foot (43,560
cubic feet).
Alluvium Material, such as sand and gravel, deposited by running water. River terraces and
outwash plains are examples of landforms composed of alluvium.
Barrens Usually refers to an area with sparse vegetation or stunted plants, caused by harsh
growing conditions such as infertile, droughty, or thin soils; also, a plant community that has
very sparse cover or is composed of stunted plants.
Bedrock Any solid rock exposed at the earth's surface or covered by unconsolidated material
such as till, gravel, or sand.
Best Management Practices: Methods, measures, or practices to prevent or reduce water
pollution, including but not limited to structural and non-structural controls, operation and
maintenance procedures, and scheduling of specific activities. Acronym is BMPs.
Blowout An area, on a dune or other sand deposit, where wind has eroded a bowl-shaped
hollow in the sand. Blowouts generally are sparsely vegetated.
Bluegreen algae A type of algae whose population often increases dramatically at high
nutrient concentrations in lakes. They can form objectionable surface scums, cause taste and
odor problems, and secrete toxins poisonous to warm-blooded animals.
Bog A wetland composed of a layer of acidic peat on which grows a specialized group of
herbs and low shrubs. Bogs are distinguished from closely related poor fens by extremely
nutrient-poor conditions and the absence of most of the minerotrophic species that occur in
poor fens.
Bounce In Hydrologic references, the rise in level in a wetland or lake resulting from a
rainstorm event. The difference in elevation between the normal water elevation and the peak
water elevation of a pond for a given size runoff event.
Brushland An upland plant community composed of shrubs and tree sprouts.
Buffer strip: A band of un-maintained, preferably native, vegetation left along the edge of a
stream, lake or wetland to filter runoff and/or stabilize the shoreline Calcareous Describes a
sailor substrate that contains a significant amount of calcium carbonate.
Canopy Aerial branches and leaves of terrestrial plants; generally the tallest layer of foliage in
a plant community.
Chlorophyll a The primary photosynthetic pigment in plants, a measure of the algal biomass
in lakes
Colluvium A deposit of rock and soil at the base of a cliff or slope,formed by gravitational
action.
Colonial nesting birds Species that nest in colonies (groups or aggregations), either with
others of the same species or in mixed-species aggregations.
Cover The proportion of the ground shaded when the living plant canopy is projected vertically
downward; also a general term used to describe any component of the habitat that conceals
animals from view.
DBH (diameter at breast height) - a standard measure of tree trunk diameter taken
approximately 4.5 feet above the ground level.
Dominant Describes a plant species that shapes the character of a community by virtue of its
size, abundance, dense shade, or effects on soils. Dominant species generally influence the
presence, growth, and distribution of other plant species in the community.
Degradation A decrease in quality.
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Detention Pond A pond designed to catch and temporarily store runoff before discharging the
water downstream. The volume of the pool of standing water in the pond is important in
determining how effective the pond will be in treating the incoming stormwater.
Dissolved Oxygen (D.O.) Oxygen that IS dissolved in water. Fish and other water organisms
need oxygen for respiration to survive. Depletion of oxygen from water can occur as a result
of chemical and biological processes, including decomposition of organic matter
Downcutting The process by which a river or stream erodes and lowers its bed, eventually
resulting in the formation df a valley or ravine.
Drift (glacial) Rock material, such as boulders, gravel, sand, silt, or clay, removed from one
area and deposited in another by glaciers Drift Includes material deposited directly by glacial
ice, such as till. as well as material deposited indirectly, such as outwash.
Ecosystem The interacting group of physical elements (such as soils, water, etc.), plants,
animals, and human communities that inhabit a particular place.
Emergent Describes a plant capable of surviving indefinitely with its root system and lower
stem in water and its upper stem above water (e.g., cattails).
Empirical Based on experiment and observation; used to describe water quality models
which are developed from measured data.
End moraine A typically hilly landform composed of material deposited at the margin of a
glacier
Ephemeral habitat A temporary habitat created by low intensity, short-lived fluctuations in
environmental factors.
Epilimnion: Upper warm layer of a lake during thermal stratification.
Esker A long, often serpentine hill or ridge composed of sand and gravel deposited by
meltwater streams flowing in a channel in a decaying ice sheet.
Eutrophication A natural process caused by the gradual accumulation of nutrients and
consequent increased biological production, and resulting in the slow filling in of a basin with
accumulated sediments, silt, and organic matter. Man's activities can increase the rate at
which eutrophication occurs.
Eutrophic Lake: A nutrient rich lake; usually shallow, green due to excessive algae growth
and with limited oxygen in the bottom layer of water.
Exotic species A species that has been introduced to an area by humans or that is present in
the area as a result of human-caused changes. (same as non native species.)
Export Coefficient An estimate of the expected annual amount of a nutrient carried from its
source to a lake.
Fen a wetland community composed of sedges, grasses, forbs, and sometimes shrubs, that
develops on peat in shallow basins.
Floating-leaved plants Aquatic plants that root on lake, pond, or river bottoms and have
leaves that float on the water surface at the end of long, flexible stems ( e.g., water-lilies).
Floodplain A flat area adjacent to a stream or river channel, created by erosion and
deposition of sediment during regular flooding. Signs of 'flooding include debris caught in
trees and ice scars at the bases of trees.
Flushing Rate The number of times per year that a volume of water equal to the lake's
volume flows through the lake.
Forb A general term for broad-leaved, herbaceous plants.
Forest A plant community with a nearly continuous to continuous canopy (70 to 100% cover)
of mature trees.
Forest-grown tree A tree that matured within a closed-canopy forest. Forest-grown trees
tend to have narrow crowns and tall, straight trunks with few lower limbs.
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B-2
Graminoid An herbaceous plant with linear, "grasslike" leaves that typically are oriented
vertically. Graminoids include grasses, sedges, and rushes.
Greenway or Greenway Corridor A linear open space area, usually composed of natural
vegetation, or vegetation that is more natural than surrounding land uses. May include paths
. or recreational trails.
Ground layer A vegetation layer, mostly less that 3 feet tall, of grasses, forbs, and woody
plants.
Ground moraine A broad and level or gently undulating landform composed of material that
was deposited underneath and sometimes at the margin of a glacier as the ice sheet melted;
also referred to as a till plain.
Grove A general term for a patch of trees less than 2 acres in area.
Grub A tree or shrub whose aboveground shoots are repeatedly killed by fire or browsing but
whose root system survives and continues to send up new shoots. The root system of a grub
may be several hundred years old; the above ground shoots are generally much younger.
Habitat The locality, site, and particular type of local environment in which plants, animals,
and other organisms live.
Herb A plant lacking a persistent above ground woody stem. Herbs include broad-leaved
flowering plants, ferns, grasses, sedges, and others.
High Water Level (HWL) The peak water surface elevation in a ponding area as a result of a
specific runoff event Once the peak is reached, the pond water elevation eventually returns to
its normal (standing) water level.
Hydrology The science and study of water in nature, including its circulation, distribution, and
its interaction with the environment
Hydrophyte A plant adapted to growing in water or on wet soils that are periodically saturated
and deficient in oxygen.
Hypolimnion Lower cooler layer of a lake during thermal stratification.
Ice block lake A lake that occurs in a depression that was formed when a block of glacial ice
was buried or surrounded by till or outwash sand, and then melted.
Ice scar A scar on a floodplain tree caused by abrasion by ice floes during spring flooding.
Impervious Surface A surface that is impermeable to the downward seepage of water; e.g.,
pavement and roof tops.
Inflorescence An arrangement of flowers on a plant, such as in a cluster or along a stalk.
Lacustrine Refers to features (such as sediments, landforms, plant communities, or animal
communities) that were formed by or are associated with a lake.
Landform A land feature, such as plain, plateau, or valley, formed by a particular geologic
process.
Life form Characteristic structural features and growth pattern of plant species (e.g., broad-
leaved deciduous shrub).
Litter layer Relatively undecomposed organic matter and debris on top of soil layer.
Loading The amount of a pollutant or other substance delivered to a lake, usually expressed
as a weight per unit time (i.e. pounds per year). The loading of a given constituent to a
receiving water is a function of the volume of incoming water and the concentration of the
constituent in the incoming water.
Loess Fine material consisting predominantly of silt with fine sand and clay. Loess is often
deposited by wind.
Macrophytes Higher plants which grow in water, either submerged, emergent, or floating.
Reeds and cattails are examples of emergent macrophytes.
Marsh A plant community of shallow wetland basins, dominated by herbaceous, emergent
aquatic plants such as cattails and bulrushes. Marshes usually have standing water
throughout the growing season.
Meltwater Water released by melting glacial ice
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8-3
Mesic A general term describing upland habitats that are intermediate between wet and dry;
also used to describe plants and plant communities that occur in mesic habitats.
Mesotrophic Lake Midway in nutrient levels between eutrophic and oligotrophiclakes.
Microhabitat A small, specialized habitat.
Mineral soil A soil composed mostly of inorganic matter, including clay, silt, sand, and gravel.
Mineral soils usually have less than 20% organic matter but may have organic surface layers
up to 12 inches thick.
Minerotrophic A general term describing wetlands with nutrient levels that fall between very
low (such as in bogs) and very high (such as in seepage meadows).
Mitigation: Actions taken to reduce an impact. Water quality mitigation measures can be
non-structural (such as street sweeping, regulation of fertilizer use, and creation/protection of
natural buffers to filter runoff) or structural (such as installation of detention basins). Properly
designed detention basins are among the most effective and reliable measures for mitigating
the water quality impacts of urban developments.
Model A mathematical representation of an event or process.
Moraine Rock and mineral debris deposited directly by glacial ice. Moraines most often
consist of unsorted rock and mineral particles.
Muck A dark-colored organic soil of highly decomposed plant material in which the original
plant parts are not recognizable.
MUSA (Metropolitan Urban Service Area) The area designated by the Metropolitan Council of
the twin cities area to receive urban services such as central sewer, urban streets, etc.
Native habitat A habitat formed and occupied by native plants and animals and little modified
by logging, farming, ditching, flood control, and the like.
Native species A species that occurs naturally within a given region.
'Native vegetation Vegetation, composed of native plants, that has been little modified by
human activities such as logging, farming, ditching, or the introduction of nonnative species.
Natural area Geographic area in which the dominant plants and animals are native species.
Natural community An assemblage that tends to recur over space and time of native plants
and animals that interact with each other and with their abiotic habitats in ways that have been
little modified by nonnative plant and animal species. Natural communities are classified and
described according to their vegetation, successional status, topography, hydrologic
conditions, landforms, substrates, soils, and natural disturbance regimes (such as wildfires,
windstorms, normal flood cycles, and normal infestation by native insects and
microorganisms).
Nonnative species A species that has been introduced to an area by humans or that is
present in the area as a result of human-caused changes.
Non-Point Source Pollution: Refers to pollution other than that caused by discharge of
pollutants through a pipe from a closed system to a receiving water. Pollution caused by
runoff from farm fields or paved streets are examples of this non-point pollution.
Normal Water Level (NWL) The elevation of the surface of the standing water pool within a
pond or wetland. Generally, the NWL is the elevation of the bottom of the primary outlet pipe
or overland flow channel. Nutrient Budget An itemized estimate of nutrient inputs and
outputs (usually for a period of one year), taking into account all sources and losses.
Nutrient Loading The input of nutrients to a lake
Nutrient Trap A type of pond or wetland that is effective at removing nutrients from water.
Nutrients Elements such as phosphorus and nitrogen that are required for plant growth.
When excess amounts are transported in stormwater they may encourage excessive algae Of
other plant growth in receiving water bodies.
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Oligotrophic Lake A relatively nutrient-poor lake, usually clear and deep with bottom wa.ters
high in dissolved oxygen.
Open-grown tree A tree that has matured in an open setting, such as a prairie or savanna.
Open-grown trees tend to have broad crowns and thick, spreading lower limbs.
Organic soil A soil in which the upper surface layers contain more than 25% organic matter.
Outcrop Bedrock that projects above the soil.
Outwash plain A plain formed of sorted and stratified material-such as layers of sand and
gravel-carried from an ice sheet and deposited by glacial meltwater.
pH A measure of the acidic or basic nature of the water; it is defined as the logarithm of the
reciprocal of the hydrogen~ion concentration in moles/liter.
Parent material The weathered rock or partly weathered soil material from which topsoil
develops.
Parts per billion (ppb) a unit of concentration, sometimes expressed as micrograms per liter
(ug/I).
Parts per million (ppm) a unit of concentration, sometimes expressed as milligrams per liter
(mg/I).
Peat soil A dark brown or black organic soil consisting largely of undecomposed or slightly
decomposed plants. Peat s'oils usually form where persistent excessive moisture slows or
inhibits the decay of plant material.
Persistent vegetation Wetland vegetation formed by emergent hydrophytic plants with stems
that normally remain standing until the beginning of the following growing season (e,g., cattails
and bulrushes).
Phosphorus A nutrient essential to plant growth. Phosphorus is the nutrient most commonly
limiting plant growth in lakes.
Phosphorus Export The amount of phosphorus carried off of a given area of land by
stormwater.
Phytoplankton Open water algae; it forms the base of the lake's food chain and produces
oxygen.
Prairie An upland plant community composed of grasses and forbs. Prairies generally lack
trees; shrubs, if present, are not prominent.
Pres'ettlement A term used for convenience to denote the time period before Euro-American
settlers moved into the Region. The Region was actually settled by American Indians for
thousands of years before European-Americans arrived.
Range (geographic) The limits of the geographic distribution of a species or group.
Rate Control: A term that refers to controlling the rate at which water is discharged from a
watershed. Rate control is often accomplished by creating ponds-either by excavation or
berming- to temporarily store runoff, then discharging the stored water at a slower rate to
downstream areas. Further reductions in the rate at which water is released from a pond can
be accomplished by reducing the size of the outlet, such as through installation of a wall in the
outlet structure with a hole (orifice) through it.
Reintroduced species Species that had been eliminated from areas where they occurred
historically and were later released back into the area by humans.
Remnant A portion or fragment of a natural community that has survived while the rest of the
community has been destroyed by logging, urban development, clearing of land for cultivation,
and other human activities.
Residence Time The amount of time it takes for water flowing into a lake to equal the lake
volume. The shorter the residence time, the more incoming water the lake is receiving relative
to its volume.
Rhizome A horizontal underground plant stem
Savanna An upland plant community formed of prairie herbs with scattered trees or groves of
trees. The canopy cover of trees in a savanna is generally between 10 and 70%.
City of Elk River, MN - Natural Resouce Inventory
8onestroo Natural Resources, Seplember 2004
8-5
Secchi Disc A device measuring the depth of light penetration In water, typically a 9-Inch,
white circular plate attached to a rope. Used to measure water transparency.
Sedge Any of a number of grasslike plants of the family Cyperaceae.
Sedimentation The process by which matter (usually soil particles) settles on a substrate
following transport by water, wind, or ice.
Seepage The slow, diffuse oozing of groundwater onto the earth's surface.
Shallow Lake Lakes with mean depth of less than 10 feet
Shrub layer A vegetation layer, usually less that 6 feet high, of shrubs and tree seedlings.
Shrub swamp A wetland community dominated by a nearly continuous to continuous canopy
(70 to 100% cover) of shrubs, such as willows and alders.
Subcanopy A vegetation layer, composed of patches of individuals of appro.ximately equal
height, that Is lower than the canopy layer; often refers to a layer of saplings, tall shrubs, or
small trees between 6 and 35 feet high.
Submergent Describes an aquatic plant that grows entirely under water.
Substrate The surface layer of organic or mineral material-such as till, outwash, or bedrock-
from which the soil is formed.
Succession The change in vegetation over time.
Swale A broad, shallow depression in a till plain or broad river plain.
Swamp A wetland community with a fairly continuous to continuous canopy of shrubs or trees,
such as speckled alder, black ash, or tamarack. Swamps generally occur in shallow basins or
wet depressions.
4Talus Rocks and other coarse mineral debris that accumulate at the base of a cliff or steep
slope.
Terrace A sandy and gravelly alluvial plain bordering a river. Terraces represent former river
floodplains, left stranded when the river level dropped because of channel downcutting or
decreased flow. Terraces are ordinarily level or nearly level and are seldom flooded.
Till Unstratified and unsorted material deposited directly by a glacier. Till consists of clay,
sand, gravel, or boulders mixed in any proportion.
Till plain A broad and level or gently undulating landform composed of material that was
deposited underneath and at the margin of a glacier as the ice sheet melted; also referred to
as a ground moraine.
Total Phosphorus (TP) A measure of all of the different forms of phosphorus in water.
Includes phosphorus dissolved in the water, suspended or incorporated in algae or other
organisms.
Total Suspended Solids (TSS) Particulate material which fioats in or is carried along in water
(e.g., algae, soil particles).
Transitional habitat A habitat present between two adjacent natural communities (for
example, the edge of a forest along a wet meadow). Transitional habitats often have features
that set them apart form the habitats formed by either of the adjacent communities
Trophic State The level of growth or productivity of a lake as measured by phosphorus
content, algae abundance, or depth of light penetration.
Understory The vegetation occurring below the canopy in a plant community.
Vine A plant with along, weak stem that grows along the ground or climbs on other vegetation
for support.
Watershed: The area of land draining into a specific body of water.
Water Transparency A measure of the clarity of water. The depth at which an object can be
seen in water.
Wetland Habitats where the soil is saturated or covered with water for part of the year.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
8-6
Woodland A wooded habitat characterized by an interrupted tree canopy: also used as a
general term to describe any tract of land with trees growing on it.
Woodland-brush land An upland plant community cDmpDsed Df a patchy canopy (10 tD 70%
cDver) of mature trees and a dense understDry of shrubs, tree shoots, and saplings. Usually
the trees occur in scattered groves with dense thickets of brush between them.
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
B-7
Bonestroo Natural Resources Project Staff
Paul J. Bockenstedt
Liza R. Gould
Rozanne M. Nohre
Sherri A. Buss
Hart D. Gilchrist
Emily L. Hamilton
Project Manager/Ecologist
Plant Ecologist & GIS
GIS
Landscape Ecologist - Ordinance Review
Database Management
GIS
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
B-8
Level 1 Land Cover Summary
Cover # of
Category Acres Polyaons
10000* 0 0
20000 5 27.7
30000 463 5,718.5
40000 155 1,458.0
50000 61 3732
60000 652 5,100.6
90000 77 9258
1413 13,603.9
'These areas are cultural in character, and
not inventoried as a part ofthis project.
L
d
S
eve 3 Lan Cover ummarv
Level 3 # of
MLCCS Alpha-numeric code Polygons Acres
Code
0 4.cd.UP 20 36
31200 3.ce.WB 16 306
32100 3.de.UP 300 4,057
32200 3.deWA 88 850
32300 3.deWB 53 471
32400 3deWC 5 29
33100 3.cd.UP. 1 6
41100 4.ce.UP 1 13
42000 4.de 1 6
42100 4.de.UP 145 1,398
42200 4.deWA 4 19
42300 4.deWB 1 10
42400 4.deWC 1 4
52100 5de.UP 8 49
52200 5deWA 5 24
52300 5.deWB 24 152
52400 5.deWC 23 141
52500 5deWF 1 7
61100 6.qe.TG 8 43
61200 6.ae.MG 174 1,367
61300 6.aeWA 12 52
I 61400 6.ae.WB 146 1,150
61500 6.qeWC 106 786
61600 6.aeWC 28 330
61700 , 6.aeWG 1 5
61800 6.aeWH 2 18
62100 6.at.GD 102 696
City of Elk River, MN - Natural Resouce Inventory
Bonestroo Natural Resources, September 2004
B-1
Level 3 # of
MLCCS Alpha-numeric code Polygons Acres
Code
62200 6.atGC 6 203.
62300 6atWA 8 86
62400 6.gtWB 40 252
62500 6.atWC 15 98
64100 6.hrSW 4 14
91100 9.rl.S. 2 377
92100 9.la.LC 2 42
92400 9IaWH. 3 46
93000 9.ww 1 3
93200 9.wwWH 1 4
93300 9.ww.OW 68 454
City of Elk River, MN - Natural Resouce Inventory
Bones/roo Natural Resources, September 2004
B-2
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