natural communities: Palustrine
, lacustrine, riverine, subterranean and
Most of the watersheds chosen for this study--the exceptions are Perry, Clear, and Crow Creeks--fall within the Des Moines Lobe, the most recently glaciated region that once contained a very high incidence of depressional, palustrine
wetlands (Figure 1).
1996 Preliminary survey of palustrine
crocodiles in Kalimantan.
The loss rate of wetlands in Massachusetts can be derived from several studies, the most extensive being the National Wetlands Inventory.(34) About twelve percent of Massachusetts's land area is wetlands.(35) About half of these total wetlands acres are palustrine
forested wetlands, and about twenty percent are tidal.(36) The closest estimate of original wetlands' extent, based on soil studies, suggests that freshwater wetlands originally encompassed 16.5 percent of the state's land; if true, this would mean that over 42 percent of original freshwater wetlands have been lost over the very long term.(37) According to the Massachusetts Audubon Society, "[s]ince 1954, wetlands in Massachusetts have been reduced by 50,000 acres....
* The type of wetland system impacted (i.e., marine, estuarine, riverine, lacustrine or palustrine
Two basins of this group are known to contain abundant sepiolite (Mees 1999a, 2001), which is also the case for palustrine
calcareous deposits in an area to the north of this region (Kautz and Porada 1976; Mees 1999b, 2002).
Typical plants from flooded fields, riparian forests, shrubs, palustrine
plants and aquatic macrophytes are part of this community.
We did not include palustrine
wetlands in the model.
Wetlands included were emergent, unconsolidated bottom, rock bottom, and aquatic bed palustrine
, scrub/shrub, dead forested, lower perennial riverine, littoral lacustrine, and beaver ponds.
Modification of an index of biotic integrity for assessing vernal ponds and small palustrine
wetlands using fish, crayfish, and amphibian assemblages along southern Lake Michigan.
Acres of wetlands and deep water habitats for 1982 and 1992 are presented in Table 6 for five Cowardin wetland systems--marine, estuarine, riverine, lacustrine, and palustrine
. Two thirds of this average acreage is palustrine
wetland, which is defined as "all non-tidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses or lichens, and all such wetlands that occur in tidal areas where salinity due to ocean-derived salts is below 0.5%" (2).