Inland
32 million hectares altogether in U.S.
7 million hectares of freshwater marshes, shallow water body that is completely
choked in emergent vegetation
- ( Everglades dominated
by reeds, cattails, and sedges)
10 million hectares of northern peatlands, mostly in Great Lakes area (111
million hectares in Canada)
22.3 million heactares of southern swamps and riparian areas
- southern swamps are deepwater
swamps with trees in them, most ecologically important, but it has suffered
the
most from deforestation
- woody wetlands dominated by
Cypress (Taxodium) and Gum (Nyssa) trees
- In Arizona, there is about
100,000 hectares of river riparian areas
Status
Review of original wetland definition: shallow water or saturated soil
unique hydric soil hydrophytic vegetation
There are several fuzzy areas in this definition. 1) Variability in flooding conditions within a year, and from year to year. Similarly, fluctuating of water levels in ground water. 2) All three characteristics may not be met (i.e. boundaries of three are not the same). 3) Different kinds of wetlands may not fit criteria.
Two types of definitions can be found. 1) one is scientific - involving classification, inventory, and research 2) one for managers and regulators - (jurisdictional) control wetland modification and changes in water quality.
The wetland definition only requires that under normal circumstances vegetation is typically adapted for survival in a saturated area. This is needed for practical limitations of rapid evaluations and reasonable amounts of effort. It is not possible to wait several years to test soil saturation levels, looking at plant life is a good enough evaluation.
Go over typical evolution of aquatic systems - wetlands
Concern is over conversion of wetland types:
- cutting down forested wetland trees turns to freshwater marshes
- "created" wetlands does not equal natural wetlands
-
constructed wetlands, artifical wetlands
Case Study with Joy Zedler in San Diego: studing wetlands to see if they
can recreate habitats for animals
- research
shows it does not
Big Problem
-loss of hardwood swamps or river bottoms
-conversion of shrub wetlands (bushes); clearing of shrubs; conversion
to freshwater marsh; conversion to farmland or urban land
-converted immediately to agriculture land and urban land, but could become
non-vegetative wetlands (ponds)
-convert farmland to non-vegetative wetland pond with government money
Example: Mississippi Marsh Land has gone from 8.5 million hectares to 2
million hectares
Note: "No Net Loss" may be misleading because there may be no loss, but significant conversion and mitigation wetlands may
be insufficient or non-functioning!