第九讲wetland.doc

文档介绍：LECTURE 14
Wetland :Conservation & Development
What is wetland?
Areas where water covers the soil
Link between water and land
water saturation in soil
Most fertile and productive ecosystems
support both aquatic and terrestrial species
found in every continents except the Antartica
Wetland classification
Functions
Physical & hydrological
natural sponge
to store water and slowly releasing it
natural filter
intercept surface runoff
remove or retain nutrients
anic wastes
reduce sediments
Functions
Physical & hydrological
impede wave action, protect shoreline against erosion
disperse flood flows, store floodwater and reduce flood damage
filter runoff and surface waters to maintain water quality
trap and deposit sediments, and reduce erosion
Recreational
hiking, fishing, boating
ecotourism
Societal
research, culture, education & aesthetics
Threats of losing and degradation of wetland
Conservation of wetland
“civilization began around wetlands; today’s civilization has every reason to l