Plant Communities of the Midwest - NatureServe

Table 5, cont.
UPLANDS
2.1 Shoreline
Sand/Mud Strands,
Beaches and Dunes
These areas contain exposed parent mineral material and are subject to active shoreline
processes, such as ice scour, wave energy, erosion and deposition. Substrate varies from coarse
grained sands, gravel, and rocks to fine-grained muds. Areas may be above the seasonal high
water mark. They may be subject to moisture and temperature extremes. Vegetation cover
varies from patchy and barren to more closed and tree covered (rarely up to 60%), but the soil
surface often remains > 50% exposed. A dune is an area where active rolling sand hills are
formed by shoreline and aeolian processes. The substrate stability is variable, and there is little
to no accumulation of organic materials. Nutrient availability is poor. (Lee et al. 1998).
2.2 Rocky Shores These areas contain exposed parent material and are subject to active shoreline processes such
as ice scour, wave energy, erosion and deposition. Substrate is generally bedrock, but may
include cobble/gravel shores. Areas may be above or below the seasonal high water mark.
They may be subject to moisture and temperature extremes. Vegetation cover varies from
patchy and barren to more closed and tree covered (up to 25%), but the rock surface often
2.3 Rocky Uplands
(Glades, Rock
Barrens, Outcrops
and Alvars)
2.4 Cliffs, Talus,
Buttes and Badlands
2.5 Forests and
Woodlands
2.6 Shrublands/
Dwarf-Shrublands
2.7 Shrub
Grasslands
2.8 Savannas and
Non-Rock Barrens
2.9 Prairies/
Grasslands
remains > 50% exposed.
These areas contain exposed parent material on moderate to steep slopes (but typically less
than 60% slope), with variable bedrock features, including rolling rock knobs and hollows,
rock reefs, blocks and fissures, rock ledges, and glacially scraped limestone pavements. Rock
type can be important to vegetation patterns. Soil development is patchy, and substrate depth
is typically < 15 cm, though variable. Sites may be subject to extremes in moisture and
temperature. The vegetation cover varies from patchy and barren, with very low cover to a
fairly good cover of herbaceous or shrubby vegetation (sometimes over 60% cover) and to a
moderately closed tree cover (up to 60%) (Nelson 1985, Lee et al. 1998).
Cliffs and buttes are vertical or near vertical (including overhangs) exposed bedrock > 3 m in
height, with associated exposed cliff rims. The bedrock type can be important, as can aspect,
which affects degree of shading. Soils are virtually non-existent, accumulating only on ledges
or rock shelves. Sites may be subject to moisture and temperature extremes, particularly if
unshaded with southerly exposures. A talus area contains slopes of rock rubble at the base of
cliffs or steep rocky slopes. Coarse rocky debris covers > 50% of substrate surface, and the
average substrate depth is < 15 cm. Bedrock type is often important. The vegetation cover
varies from patchy and barren to more closed and tree covered (up to 60%), but the soil
surface often remains > 50% exposed (Nelson 1985, Lee et al. 1998). Bluffs and badlands are
vertical or near vertical exposed parent mineral soils such as loess, clays, or badlands soils, and
the associated eroded clay plains at the base of these slopes. Soils generally have no horizons.
Sites are subject to moisture and temperature extremes. The vegetation is typically sparse,
rarely exceeding 25%.
Forests and woodlands occur on mineral soils (rarely on unconsolidated materials) over a wide
range of depths, but soils generally are > 15 cm deep. Where rocks are exposed at the surface
(such as in boulderfields or glacially scoured bedrock regions), they have a fairly continuous
vegetation cover. Tree canopy cover varies from 25% to 100%.
Shrublands and dwarf-shrublands occur on mineral soils (rarely on unconsolidated materials)
over a wide range of depths. Soils are at least 15 cm deep. Temperature, droughts, and/or fire
limit shrub cover (which ranges from 25% to 100%); herbaceous cover is generally continuous.
Shrub Grasslands occur on mineral soils (rarely on unconsolidated materials) over a wide
range of depths. Soils are at least 15 cm deep. Temperature, droughts, and fire limit shrub
canopy cover (which ranges from 10 to 25%), herbaceous cover is generally continuous.
Savannas and Non-Rock Barrens occur on mineral soils (rarely on unconsolidated materials)
over a wide range of depths. Soils are at least 15 cm deep, and rocks are rarely exposed at the
surface. Temperature, droughts, and fire limit tree canopy cover (which ranges from 10% to
25%), but herbaceous cover is generally continuous (Lee et al. 1998). Thin soil or bedrock
savannas are sometimes termed barrens, but such “Non-Rock Barrens are distinct from Rock
Barrens (see 2.3 above) which contain exposed bedrock at the surface and where the
vegetation is discontinuous to sparse.
Prairies/Grasslands occur on mineral soils (rarely on unconsolidated materials) over a wide
range of depths. Soils are at least 15 cm deep. Temperature, droughts, and fire limit woody
canopy encroachment (woody cover does not typically exceed 10%); herbaceous cover is
generally continuous.
PLANT COMMUNITIES OF THE MIDWEST – 2001
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