生态学PPT

Management and policy decisions of wetland functions and values tend to be made anthropocentrically
• These values may be the result of ecosystem functions and processes • The value may be very different for diverse stakeholders (利益相关者） ---Regional (global tends to be ignored in the U.S., but not in Europe) ---Specific function based (e.g. birdwatching,
Natural wetland
1.Wetland functions and values 2. Wetland for waste water treatment
What is wetland?
• Wetland are defined variously to include a wide spectrum of habitats where the land is inundated by shallow water or is saturated by surface or ground water at a frequency and duration every year that water becomes the primary factor controlling the environment and the associated plant and animal life.
Educational Values:
• High productivity and high diversity • Easy to construct in outdoor classrooms • Used at all grade and age levels ---First microscope lab ---Playing in the mud
Global Ecosystem Processes: Source, Sink, Transformer
• Carbon Storage --hydric soils . nutrient rich . slow decomposition -- plants and animals -- export to adjacent ecosystems --fossil fuels (Carboniferous Era swamps) -- heavy metal retention • Nitrogen cycling nitrate reduction (air) Storage • Phosphorus cycling • Sulfur cycling
Water Storage:
• Bottomland forest in the Mississippi basin before European settlement retained about 60 days of river discharge. Today, what is left retains less than 12 days of discharge.
Wetland have functions and values at a number of levels
• Global biogeochemical cycles (hardest to quantify, most important for life) • Soils and productivity • Food and shelter for animals • Plant establishment and nourishment • Human values ---Flood control ---Fish and Wildlife
Aesthetic Values
• Art is an expression of nature --Duck stamps -- landscapes • Beauty of plants and animals (nonconsuptive) --Birdwatching --Canoe trips (独木舟） --Pioneering instinct --Solitude and wild
Population and Community Values
•Vegetation Timber •Fur •Fish •Shellfish •Birds •Threatened and Endangered Species
Herbaceous Vegetation:
•Ryther and others argued that a 1,000 ha water hyacinth farm could produce 10,000,000,000,000 BTU of methane per year and at the same time remove all the nitrogen from the wastewater of 700,000 people •Peat production
• USACOE determined that the Charles River (MA) floodplains were so effective that it was cheaper to purchase wetlands than to build control structures. The 3,400 ha of wetlands were worth $17 million per year in flood damage reduction.
Water Quality Improvement:
• • • • • Kentucky’s #1 pollutant-sediment, is settled Chealation of heavy metals Transformation of nutrients Permanent burial High diversity of decomposers and decomposition processes

Fur and Skin:
• Harvest over 10 million muskrat pelts per year in the US • Nutria escaped from captivity in Louisiana and are harvested for fur and to reduce their damage • Beaver (河狸） • Minks (水貂） • Alligators (鳄鱼）where abundant
hunting, flood control, endangered species, art, history)
Value is viewpoint dependent:
• Swamps and marshes were generally considered ----Farmlands yet undrained ---- Places that caused disease -----Dangerous and foreboding (不祥之兆） -----Hindrances to navigation ----Convenient locations for development ----valueless
Historical Values:
• Floodplains bury and preserve artifacts • Slow decomposition, and tannins, keep artifacts fresh • Deposition of pollen and fossils allow ecologists to use them as time machines
Wetlands have been called the “kidneys of the landscape” because they can retain and transform nutrients and “waste” • Agricultural runoff • Removal of sulfates by reducing them to sulfides and binding • Human waste • Eutrophication
• Can keep up base flow during droughts, and recharge shallow aquifers
Storm Abatement
• New Orleans --Barrier islands are designed to take the storms energy -- Loss of wetlands and water storage • Public Cost? $$$$$$$$ • Buildings on floodplains may become artificial reefs for fish
What are functions and values?
• Function-assigned duty or activity; something closely related to another thing and dependent upon it for its existence, value, or significance • Value-suitable equivalent of something else; utility or merit; worthwhile Source: American Heritage Dictionary