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Biodiversity
The US South and the Middle
Atlantic Coastal ecoregion contain very high levels of native terrestrial
diversity, but it is in the freshwater aquatic world where the region scores
extremely high. In a companion assessment to the terrestrial one, World
Wildlife Fund examined the major freshwater aquatic taxonomy according to major
watersheds for all of North America. Two
major drainage basins intersect this region - Chesapeake Bay and South
Atlantic. Species richness and
endemism or uniqueness results are very high for three groups: fishes, mussels,
and crayfishes. As you can see the southern forests
is either at the top or near the top in the map below. It shows the total freshwater aquatic species richness and endemism for North America. (Abell et al 2000).
Land that is inundated with
water for at least part of the year can be characterized as a wetland. These
include marshes, swamps, bottomland hardwoods, pocosins and wet flats. They can
be located near the shore, where tides flood the soil daily, in fluvial flood
plains or in depressed areas of land where rainwater collects. Regardless of
location, these lands all share similar characteristics in vegetation and soil.
The plants are well adapted to wet, anoxic conditions for at least part of the
year; the soils have properties of color, texture and odor that reflect their
development in water-logged conditions.
Wetlands are often split into
two categories:
Coastal Wetlands:
Coastal or tidal wetlands are usually associated with the estuaries along the
shore where seawater and freshwater mix. The salinity creates a harsh
environment unfavorable for most life except for certain hardy grasses.
Inland Wetlands:
Inland or non-tidal wetlands are found near bodies of water such as rivers and
lakes, or in low-lying lands where the groundwater level intercepts the land
surface. Vegetation varies from grasses to shrubs to trees. Many of these are
in saturated conditions for only part of the year, but the seasonal wetlands
are just as important and perform vital functions.
Historically thought as useless,
disease festering plots of land, wetlands are now understood to be some of the
most important, productive and biologically diverse ecosystems in the world.
Many of these products and functions provided by wetlands including water
filtration, providing habitat for commercial species and many more-directly
benefit humankind and are termed ecosystem services.
To
learn more about industrial forestry's impact on wetlands in the US South click
here
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