Ohio subset of Plant Communities of the Midwest ... - NatureServe

Open and Emergent Marshes: Eastern Emergent Marshes
Typha spp. - Schoenoplectus acutus - Mixed Herbs Midwest Herbaceous Vegetation
Cattail Species - Hardstem Bulrush - Mixed Herbs Midwest Herbaceous Vegetation
Midwest Mixed Emergent Deep Marsh
CEGL002229
DESCRIPTION: This deepwater emergent marsh community is dominated by perennial herbaceous vegetation with
graminoid leaves. A typical example of this marsh contains a mosaic of emergents, submergents, and floating-leaved
plants interspersed with areas of open water (Harris et al. 1996). Various kinds of emergents may dominate a marsh
depending on the water depth. Quite often the vegetation arranges itself in belts (wetland zonation), with a particular
species or range of species occupying specific depths from the shoreline to deep open water. Marshes may display
areas of open water, but vegetation dominates (>30% cover). Typha latifolia, Typha angustifolia, and Schoenoplectus
acutus (= Scirpus acutus) dominate this dynamic ecosystem. Sedges are also common (e.g. Carex lupuliformis and
Carex hyalinolepis in the eastern part of the range). A diverse assemblage of grasses, floating-leaved aquatics, and
submerged aquatics are present (TNC 1995a).
These highly productive wetlands are found in glacial potholes, river valleys, ponds, and on lakeplains. They are
characterized by continuous inundation and are considered a deep marsh. Water depth averages 0.3-0.6 m, ranging
from several centimeters to more than one meter for a significant part of the growing season. Seasonal flooding during
winter and spring or flooding during heavy rains help maintain these marshes by causing water exchange which
replenishes freshwater and circulates nutrients and organic debris. Soils can be mineral or organic but are saturated,
flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part.
Vegetative diversity and density are highly variable in response to water depth, water chemistry, and natural forces.
Seasonal flooding and heavy rains influence vegetative growth, aquatic animals, and nutrient cycling in marsh ecosystems.
COMMENTS: 2, MCS. This community type is very broadly defined. It can be highly dynamic from one season to the
next, and species composition and density are very dependent on water regime and sometimes the mineral content of
water and soil (Niering 1985). Deep marsh is defined as having water depths of 15 cm to over 1 m throughout all or most
of the growing season (Shaw and Fredine 1971, in Eggers and Reed 1987). The concept and distribution of this
community in the Southeast needs reassessment; it should be compared to Typha latifolia Southern Herbaceous
Vegetation (CEGL004150), particularly in the Mississippi alluvial plain of Missouri (M. Leahy pers. comm. 1999). Many of
the presettlement occurrences of this community have been drained and converted to cropland or destroyed by siltation,
which greatly accelerates the natural successional process from shallow inundation to moist soil. Lythrum salicaria is an
aggressive exotic species that threatens this community in Canada, the Northeast, and more recently in the Midwest.
Stands in Province 212 may deserve to be recognized as a separate northern type, but further data are needed.
CONSERVATION RANK: G4. This type is subject to many forms of human impact, particularly draining for farmland.
DISTRIBUTION: This community is found in glacial potholes, river valleys, ponds, and on lake plains throughout the
midwestern and parts of the eastern United States, ranging from Ohio and Ontario west to North Dakota, south to
Nebraska and east to Alabama.
USFS ECOREGIONS: 212He:CCC, 212Hj:CCP, 212Ho:CCC, 212Hq:CCP, 212Ht:CCC, 212Hv:CCC, 212Ib:C, 212Ja:CPP,
212Jb:CP, 212Jc:CP, 212Jf:CPP, 212Jj:CPP, 212Jl:CPP, 212Jm:CPP, 212Jn:CP, 212Jo:CP, 212Ka:CPP, 212Mb:CPP,
212Na:CCP, 212Nb:CCP, 212Nc:CCC, 212Nd:CC, 222A:CP, 222Cg:CCP, 222D:CP, 222E:CP, 222G:CP, 222Ha:CCC,
222Hb:CCC, 222Ia:CCC, 222Jc:CCC, 222Jg:CCC, 222Jh:CCC, 222Ji:CCC, 222Jj:CCC, 222Kd:CCC, 222Ke:CCC, 222Kf:CCC,
222Kg:CCC, 222Kj:CCC, 222Mc:CCC, 222Md:CCC, 222Me:CCC, 222Na:CCC, 234A:PP, 251Aa:CCC, 251Ab:CCC,
251Bb:CCC, 251Bd:CCC, 251Be:CCC, 251Cb:CCC, 251Cf:CCC, 251Cg:CCC, 251Ch:CCC, 251Cm:CCC, 251Cp:CCC,
251Dg:CCC, 251Eb:CCC
CONSERVATION REGIONS: 35:C, 36:C, 37:P, 43:C, 44:P, 46:C, 47:C, 48:C, 50:
STATES: AL IA IL IN KY MI MN MO ND NE OH SD TN WI PROVINCES: ON
MIDWEST HERITAGE SYNONYMY: IL marsh (S); marsh (N) I
IN marsh +
MI inland emergent marsh +
MN mixed emergent marsh (prairie section); mixed emergent marsh (forest section) I
MO freshwater marsh +
NE freshwater marsh +
OH mixed emergent marsh; mixed emergent riverine community I
WI deep marsh (mixed emergent subtype) =
OTHER SYNONYMY: Marsh: Mixed: Mineral Substrate (W5) (Harris et al. 1996) B, Marsh: Mixed: Organic Substrate
(W10) (Harris et al. 1996) B
USNVC HIERARCHY: TYPHA (ANGUSTIFOLIA, LATIFOLIA) - (SCHOENOPLECTUS SPP.) SEMIPERMANENTLY FLOODED HERBACEOUS
ALLIANCE (V.A.5.N.l)
PLANT COMMUNITIES OF THE MIDWEST – 2001. APPENDIX: ASSOCIATION DESCRIPTIONS
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