Wetland Plants and Plant Communities of Minnesota and Wisconsin
Key To the Wetland Plant Communities
1A. Mature trees (dbh of 6 inches or more) are present and form closed stands
(more than 17 trees per acre; more than a 50 percent canopy cover) on wet, lowland
soils (usually floodplains and ancient lake basins).
- 2A. Hardwood trees are dominant; usually alluvial, peaty/mucky, or poorly-drained
mineral soils.
- 3A. Silver maple, American elm, river birch, green ash, black willow
and/or eastern cottonwood are dominant; growing on alluvial soils associated
with riverine systems...............FLOODPLAIN
FOREST
- 3B. Black ash, yellow birch, silver maple and/or red maple are dominant;
northern white cedar may be subdominant; growing on poorly-drained mineral
or peat/muck soils, often associated with ancient lake basins...............HARDWOOD
SWAMP
- 2B. Coniferous trees are dominant; soils usually peaty.
- 4A. Tamarack and/or black spruce are dominant; growing on a continuous
sphagnum moss mat and acid, peat soils...............CONIFEROUS
BOG
- 4B. Northern white cedar and/or tamarack are dominant; continuous
sphagnum moss mat absent; usually growing on neutral to alkaline peat/muck
soils...............CONIFEROUS SWAMP
1B. Mature trees are absent or, if present, form open, sparse stands; other
woody plants, if present, are shrubs or saplings and pole-size trees (dbh
less than 6 inches) less than 20 feet high and growing on wet, lowland, or
poorly-drained soils, or in groundwater seepage areas.
- 5A. Community dominated by woody shrubs.
- 6A. Low, woody shrubs usually less than 3 feet high; sphagnum moss
mat layer may or may not be present.
- 7A. Shrubs are ericaceous and evergreen growing on a sphagnum
moss mat layer; peat soils are acidic...............OPEN
BOG
- 7B. Shrubs are deciduous, mostly shrubby cinquefoil, often growing
on sloping sites with a spring-fed supply of internally flowing,
calcareous waters; other calciphiles are also dominant; sphagnum
moss mat layer absent; muck/poorly-drained mineral soils are alkaline...............CALCAREOUS
FEN
- 6B. Tall, woody deciduous shrubs usually greater than 3 feet high;
sphagnum moss mat layer absent...............SHRUB
SWAMPS
- 8A. Speckled alder is dominant; usually on acidic soils in and
north of the vegetation tension zone...............ALDER
THICKET
- 8B. Willows, red-osier dogwood, silky dogwood, meadowsweet and/or
steeplebush are dominant on neutral to alkaline poorly-drained muck/mineral
soils; found north and south of the vegetation tension zone...............SHRUB-CARR1
- 5B. Community dominated by herbaceous plants.
- 9A. Essentially closed communities, usually with more than 50 percent
cover.
- 10A. Sphagnum moss mat on acid peat soils; leatherleaf, pitcher
plants, certain sedges, and other herbaceous species tolerant of
low nutrient conditions may be present...............OPEN
BOG
- 10B. Sphagnum moss mat absent; dominant vegetation consists of
sedges (Cyperaceae), grasses (Gramineae), cattails, giant bur-reed,
arrowheads, forbs and/or calciphiles. Soils are usually neutral
to alkaline poorly-drained mineral soils and mucks.
- 11 A. Over 50 percent of the cover dominance contributed by
the sedge family, cattails, giant bur-reed, arrowheads, wild
rice, and/or giant reed grass (Phragmites).
- 12A. Herbaceous emergent plants growing on saturated soils
to areas covered by standing water up to 6 inches in depth
throughout most of the growing season.
- 13A. Major cover dominance by the sedges (primarily
genus Carex)...............SEDGE
MEADOW
- 13B. Major cover dominance by cattails, bulrushes,
water plantain, Phragmites, arrowheads, and/or
lake sedges...............SHALLOW
MARSH
- 12B. Herbaceous submergent, floating and emergent plants
growing in areas covered by standing water greater than
6 inches in depth throughout most of the growing season...............DEEP
MARSH
- 11 B. Over 50 percent of the cover dominance contributed by
grasses (except wild rice and Phragmites), forbs and/or
calciphiles.
- 14A. Spring-fed supply of internally flowing, calcareous
waters, often sloping sites; calciphiles such as sterile
sedge, wild timothy, Grass-of- Parnassus and lesser fringed
gentian are dominant...............CALCAREOUS
FEN
- 14B. Water source(s) variable; calciphiles not dominant.
- 15A. Soils saturated to inundated during the growing
season; prairie grasses such as big bluestem, prairie
cordgrass and/or Canada bluejoint grass are usually
dominant, and various species of lowland prairie forbs
are present...............WET
TO WET-MESIC PRAIRIE
- 15B. Site rarely inundated, but soils are saturated
for all or part of the growing season; dominated by
forbs such as giant goldenrod and/or grasses such
as redtop and reed canary grass...............FRESH
(WET) MEADOW
- 9B. Essentially open communities, either flats or basins usually with
less than 50 percent vegetative cover during the early portion of the
growing season, or shallow open water with submergent, floating and/or
floating-leaved aquatic vegetation.
- 16A. Areas of shallow, open water (to 6.6 feet in depth)
dominated by submergent, floating and/or floating-leaved
aquatic vegetation...............SHALLOW,
OPEN WATER COMMUNITIES
- 16B. Shallow depressions or flats; standing water may
be present for a few weeks each year, but are dry for
much of the growing season; often cultivated or dominated
by annuals such as smartweeds and wild millet...............SEASONALLY
FLOODED BASIN
1Buckthorns (Rhamnus spp.) may occur as dominant shrubs
or small trees in disturbed shrub-carrs.
 |
Figure 5 - Generalized cross section of a meadow-marsh-open
water complex |
 |
Figure 6 - Generalized cross section of wetland plant communities
in a river valley |
 |
Figure 7 - Generalized cross section of wetland plant communities
in a lake basin |
 |
Figure 8 - Generalized cross section of a bog |
Previous Section -- Introduction
Return to Contents
Next Section -- Comprehensive Plant Family List