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

Open and Emergent Marshes: Great Lakes Coastal Marshes and Complex
Potamogeton zosteriformis - Ceratophyllum demersum - Elodea canadensis Southern Great Lakes
Shore Herbaceous Vegetation
Flat-stem Pondweed - Coontail - Canadian Waterweed Southern Great Lakes Shore Herbaceous
Vegetation
Southern Great Lakes Submergent Marsh
CEGL005152
DESCRIPTION: Dominant submerged aquatics include Ceratophyllum demersum, Chara spp., Elodea canadensis,
Heteranthera dubia, Myriophyllum spicatum, Najas flexilis, Potamogeton spp. (including Potamogeton amplifolius,
Potamogeton friesii, Potamogeton gramineus, Stuckenia pectinata (= Potamogeton pectinatus), Potamogeton
zosteriformis), and Vallisneria americana. Floating aquatics include Lemna minor, Lemna trisulca, and Spirodela
polyrrhiza. Other rooted aquatics include Nymphaea odorata, Nuphar lutea ssp. advena, Nelumbo lutea, Peltandra
virginica, and Sagittaria latifolia. The exotic Hydrocharis morsus-ranae is increasingly common in the St. Lawrence,
Lake Ontario, and Lake Erie marshes (Minc and Albert 1998).
Remaining stands in the area are primarily found in lacustrine estuaries, barrier-beach lagoons, or sand-spit swales.
In the Great Lakes, the estuaries are often formed at the mouths of rivers drowned by the post-glacial rise in lake
level, whereas in the St. Lawrence these are formed from small streams or rivers that occupy apparent pre-glacial
valleys that have been partly filled in by outwash and alluvial deposits to form fairly broad , flat basins. Storms,
seiches, and water level cycles create a very dynamic pattern of species composition and structure in the vegetation.
Water depth generally exceeds 0.3 m.
Stands appear to be correlated with greater site protection from wave action and storms (Minc 1996). The southern
Great Lakes emergent marshes may have an increased level of dominance in Typha spp. because of a reduction in
the amplitude of natural water-level fluctuations (Wilcox et al. 1993, in Minc and Albert 1998). It is thought that the
natural fluctuations favor more diverse vegetation because they permit a wider range of habitat, exclude species that
cannot tolerate water-depth changes or favor species requiring periodic exposures of fertile substrates.
COMMENTS: 2, MCS. This type may often be tracked as part of the Great Lakes Wetlands Complex (CECX002002).
CONSERVATION RANK: G3G4. This type is found in at least 24 sites in the southern Great Lakes, as part of a number
of different Great Lakes Wetland Complexes, but many are disturbed. Only 12 sites were ranked A or B quality.
Marshes along Lake Erie and Lake Ontario are often subject to high levels of agricultural disturbances characteristic
of the fertile, flat lakeplain soils, along with heavy manipulation of the shoreline through diking and rip-rap.
DISTRIBUTION: This deep emergent marsh community typically occurs in the southern Great Lakes region of the
United States and Canada, including southern Lake Michigan, Lake St. Clair, Lake Erie, Lake Ontario, and into the
St. Lawrence River, and possibly Lake Champlain.
USFS ECOREGIONS: 212He:CPP, 212Hi:CPP, 212Hj:CPP, 212Hl:CPP, 212Hm:CPP, 212Ho:CPP, 212Hp:CP, 212Hr:CP,
212Hs:CP, 212Ht:CP, 212Hv:CP, 212Hw:CPP, 212Hx:CPP, 212Hy:CPP, 212Ib:CPP, 212Ja:CCC, 212Jb:CC, 212Jk:CCP,
212Jn:CC, 222:P
CONSERVATION REGIONS: 47:P, 48:C
STATES: MI NY OH PA VT WI PROVINCES: ON
MIDWEST HERITAGE SYNONYMY: MI Great Lakes marsh complex +
OH submerged marsh I
WI submerged aquatic (southern great lakes subtype) =
OTHER SYNONYMY:
USNVC HIERARCHY: POTAMOGETON SPP. - CERATOPHYLLUM SPP. - ELODEA SPP. PERMANENTLY FLOODED HERBACEOUS
ALLIANCE (V.C.2.N.a)
PLANT COMMUNITIES OF THE MIDWEST – 2001. APPENDIX: ASSOCIATION DESCRIPTIONS
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