Diem Le
Wetlands
by Jon A. Kusler, William J. Mitsch and Joseph S. Larson
A:
- Contant change makes wetlands ecologically rich they are often as diverse as rain forests.
- Shallow water-fed systems are central to the life cycle of many plants and animals some are endangered.
- Provide a habitat as well as spawning grounds for an extraordinary variety of creatures and nesting areas for migratory birds.
- Wetlands also have commercial and utilitarian functions.
-Wetlands limit the damaging e›ects of waves, convey and store floodwaters, trap sediment and reduce pollution— the last attribute has earned them the sobriquet “nature’s kidneys.”
-No such numbers are available internationally, but we estimate that 6% of all land is currently wetlands.
-The complex dynamics of wetlands complicate efforts to create policies for preserving them.
-Their management and protection must incorporate a realistic definition, one that encompasses all these intricate ecosystems—from marshes, bogs and swamps to vernal pools, playa lakes and prairie potholes.
-All share the recognition that wetlands are shollow-water systems, or areas where water is at or near the surface for some time.
-They arise in flat, tidally inundated but protected areas, such as salt marshes and mangrove swamps.
-Wetlands exist next to fresh-water rivers, streams and lakes and their floodplains.
-Wetlands comprise fresh-water marshes, potholes, meadows, playas and vernal pools where vegetation is not woody, as well as swamps where it is.
-Wetlands can also flourish on slopes and at the base of slopes, supplied by springs, and as bogs and fens fed by precipitation and groundwater.
-Water rises or falls in accordance with tides, precipitation or runoff the activities of humans and other animals can also determine water levels.
-Hurricanes and high-velocity floods scour sediments and organic matter, removing them from wetlands or creating wetlands nearby.
-This anomalous feature of wetlands the way that short term destruction ansures long term gain is poorly understoof by the general public.
-Some researchers have suggested that trees in the coastal mangrove swamps reach maturity at about 30yr of age, a periodicity that coincides almost perfectly with the frequency of hurricanes in the tropics.
-A wetland encompasses an array of shollow-water and saturated soil encironments that possess some elements of a terrestrial system and some of an aquatic system.
-Water levels rise and fall continuously, portions of wetlands and in some cases, entire at times resemble true aquatic system, at times terrestrial systems and at time intermediate systems.
-Wetlands also difer from deep-water aquatic systems in their sensitivity to the effects of water-level changes.
-A one-foot change in the level of a lake or a river brings about little difference in a system’s boundaries or functions.
-Certain wetland vegetation-sedge, grasses or floating plants often grows in 1 location during a wet year, another location during an intermediate year and not at all during a dry year.
-Alterations in their water levels give rise to a series of ecological niches that can support terrestrial, partially aquatic and fully aquatic plants and animals.
-short-legged birds such as green-backed herons and limpkins feed along shallow-water shorelines.
-Longer-legged species, including egrets and great blue herons, feed in deeper water.
-Shifts in water levels serve to trigger nesting by wood storks in Florida and breeding by ducks in prairie potholes.
-Rising and falling water levels not only influence the internal character of a wetland, but they also link wetlands to 1 another and to other aquatic system.
-their sensitivity to water levels, wetlands are highly dependent on the quantity and quality of water in their immediate area.
-Wetlands bordering major lakes and streams may be less sensitive to such natural changes.
-Wetlands can serve as reprodutive or feeding sites for some species only if they are connected with other waterways.
-The wetlands then cleanse these waters by retaining sediments as well as phosphorus and other chemical.
-Landfills, dikes or other measures that isolate wetlands from nearby wetlands or waters can reduce
their ability to provide flood storage, water purification and habitats.
-Barriers also can prevent wetland plants and animals with highly sensitive aquatic tolerances from migrating up and down gentle slopes.
-A sea wall or a dike at the landward boundary of a salt marsh can prevent the inland migration of the marsh when the sea level rises.
-Increased amounts of sediment, nutrients and pesticides from watersheds undergoing development can drastically alter the biological makeup of a wetland and overload its ability to purge pollutants if they are added beyond the wetland's ability to assimilate them.
-Isolated wetlands arising in topological depressions are quite vulnerable because they are not periodically purged of sediment by storms or high-velocity river flows.
-Watershed development and diversions that decrease the freshwater flow of rivers similarly threaten many estuarine wetlands by reducing the quantity of freshwater and inceasing salinity.
-The debate has pivoted around the problem of devising management stratigies that provide certainly for developers while protecting the ecological features of wetlands.
-The bill would requira that hydric vegetation be present in every wetland.
-The expense of using modeling to foresee wate levels is prohibitive: one study to determine the probability of a 100yr or extremely rare, flood on about half the nation's floodplains cost more than $870 million.
-A wetland's ability to control floowater or maintain water quality can be seen immediately downstream.
-Under the bill downstream landowners are not compensated for the fact that their wetlands can no longer fulfill these functions.
-Water levels vary within relatively well defined ranges in most wetlands and can therefore provide a foundation for definition and regulation.
Wetlands
by Jon A. Kusler, William J. Mitsch and Joseph S. Larson
A:
- Contant change makes wetlands ecologically rich they are often as diverse as rain forests.
- Shallow water-fed systems are central to the life cycle of many plants and animals some are endangered.
- Provide a habitat as well as spawning grounds for an extraordinary variety of creatures and nesting areas for migratory birds.
- Wetlands also have commercial and utilitarian functions.
-Wetlands limit the damaging e›ects of waves, convey and store floodwaters, trap sediment and reduce pollution— the last attribute has earned them the sobriquet “nature’s kidneys.”
-No such numbers are available internationally, but we estimate that 6% of all land is currently wetlands.
-The complex dynamics of wetlands complicate efforts to create policies for preserving them.
-Their management and protection must incorporate a realistic definition, one that encompasses all these intricate ecosystems—from marshes, bogs and swamps to vernal pools, playa lakes and prairie potholes.
-All share the recognition that wetlands are shollow-water systems, or areas where water is at or near the surface for some time.
-They arise in flat, tidally inundated but protected areas, such as salt marshes and mangrove swamps.
-Wetlands exist next to fresh-water rivers, streams and lakes and their floodplains.
-Wetlands comprise fresh-water marshes, potholes, meadows, playas and vernal pools where vegetation is not woody, as well as swamps where it is.
-Wetlands can also flourish on slopes and at the base of slopes, supplied by springs, and as bogs and fens fed by precipitation and groundwater.
-Water rises or falls in accordance with tides, precipitation or runoff the activities of humans and other animals can also determine water levels.
-Hurricanes and high-velocity floods scour sediments and organic matter, removing them from wetlands or creating wetlands nearby.
-This anomalous feature of wetlands the way that short term destruction ansures long term gain is poorly understoof by the general public.
-Some researchers have suggested that trees in the coastal mangrove swamps reach maturity at about 30yr of age, a periodicity that coincides almost perfectly with the frequency of hurricanes in the tropics.
-A wetland encompasses an array of shollow-water and saturated soil encironments that possess some elements of a terrestrial system and some of an aquatic system.
-Water levels rise and fall continuously, portions of wetlands and in some cases, entire at times resemble true aquatic system, at times terrestrial systems and at time intermediate systems.
-Wetlands also difer from deep-water aquatic systems in their sensitivity to the effects of water-level changes.
-A one-foot change in the level of a lake or a river brings about little difference in a system’s boundaries or functions.
-Certain wetland vegetation-sedge, grasses or floating plants often grows in 1 location during a wet year, another location during an intermediate year and not at all during a dry year.
-Alterations in their water levels give rise to a series of ecological niches that can support terrestrial, partially aquatic and fully aquatic plants and animals.
-short-legged birds such as green-backed herons and limpkins feed along shallow-water shorelines.
-Longer-legged species, including egrets and great blue herons, feed in deeper water.
-Shifts in water levels serve to trigger nesting by wood storks in Florida and breeding by ducks in prairie potholes.
-Rising and falling water levels not only influence the internal character of a wetland, but they also link wetlands to 1 another and to other aquatic system.
-their sensitivity to water levels, wetlands are highly dependent on the quantity and quality of water in their immediate area.
-Wetlands bordering major lakes and streams may be less sensitive to such natural changes.
-Wetlands can serve as reprodutive or feeding sites for some species only if they are connected with other waterways.
-The wetlands then cleanse these waters by retaining sediments as well as phosphorus and other chemical.
-Landfills, dikes or other measures that isolate wetlands from nearby wetlands or waters can reduce
their ability to provide flood storage, water purification and habitats.
-Barriers also can prevent wetland plants and animals with highly sensitive aquatic tolerances from migrating up and down gentle slopes.
-A sea wall or a dike at the landward boundary of a salt marsh can prevent the inland migration of the marsh when the sea level rises.
-Increased amounts of sediment, nutrients and pesticides from watersheds undergoing development can drastically alter the biological makeup of a wetland and overload its ability to purge pollutants if they are added beyond the wetland's ability to assimilate them.
-Isolated wetlands arising in topological depressions are quite vulnerable because they are not periodically purged of sediment by storms or high-velocity river flows.
-Watershed development and diversions that decrease the freshwater flow of rivers similarly threaten many estuarine wetlands by reducing the quantity of freshwater and inceasing salinity.
-The debate has pivoted around the problem of devising management stratigies that provide certainly for developers while protecting the ecological features of wetlands.
-The bill would requira that hydric vegetation be present in every wetland.
-The expense of using modeling to foresee wate levels is prohibitive: one study to determine the probability of a 100yr or extremely rare, flood on about half the nation's floodplains cost more than $870 million.
-A wetland's ability to control floowater or maintain water quality can be seen immediately downstream.
-Under the bill downstream landowners are not compensated for the fact that their wetlands can no longer fulfill these functions.
-Water levels vary within relatively well defined ranges in most wetlands and can therefore provide a foundation for definition and regulation.
B:
Provide a habitat as well as spawning grounds for an extraordinary variety of creatures and nesting areas for migratory birds.Wetlands also have commercial and utilitarian functions.Wetlands limit the damaging e›ects of waves, convey and store floodwaters, trap sediment and reduce pollution— the last attribute has earned them the sobriquet “nature’s kidneys.”No such numbers are available internationally, but we estimate that 6% of all land is currently wetlands.The complex dynamics of wetlands complicate efforts to create policies for preserving them.Their management and protection must incorporate a realistic definition, one that encompasses all these intricate ecosystems—from marshes, bogs and swamps to vernal pools, playa lakes and prairie potholes.All share the recognition that wetlands are shollow-water systems, or areas where water is at or near the surface for some time.
Increased amounts of sediment, nutrients and pesticides from watersheds undergoing development can drastically alter the biological makeup of a wetland and overload its ability to purge pollutants if they are added beyond the wetland's ability to assimilate them.Isolated wetlands arising in topological depressions are quite vulnerable because they are not periodically purged of sediment by storms or high-velocity river flows.Watershed development and diversions that decrease the freshwater flow of rivers similarly threaten many estuarine wetlands by reducing the quantity of freshwater and increasing salinity.The bill would require that hydraulic vegetation be present in every wetland.The expense of using modeling to foresee water levels is prohibitive: one study to determine the probability of a 100yr or extremely rare, flood on about half the nation's floodplains cost more than $870 million.A wetland's ability to control floowater or maintain water quality can be seen immediately downstream.Under the bill downstream landowners are not compensated for the fact that their wetlands can no longer fulfill these functions.Water levels vary within relatively well defined ranges in most wetlands and can therefore provide a foundation for definition and regulation.
C:
Contant change makes wetlands ecologically rich they are often as diverse as rain forests.Shallow water-fed systems are central to the life cycle of many plants and animals some are endangered.The wetlands then cleanse these waters by retaining sediments as well as phosphorus and other chemical.Landfills, dikes or other measures that isolate wetlands from nearby wetlands or waters can reduce their ability to provide flood storage, water purification and habitats.Barriers also can prevent wetland plants and animals with highly sensitive aquatic tolerances from migrating up and down gentle slopes.Water rises or falls in accordance with tides, precipitation or runoff the activities of humans and other animals can also determine water levels.Hurricanes and high-velocity floods scour sediments and organic matter, removing them from wetlands or creating wetlands nearby.
So What?
Water levels rise and fall continuously, portions of wetlands and in some cases, entire at times resemble true aquatic system, at times terrestrial systems and at time intermediate systems.Wetlands also difer from deep-water aquatic systems in their sensitivity to the effects of water-level changes.A one-foot change in the level of a lake or a river brings about little difference in a system’s boundaries or functions.Certain wetland vegetation-sedge, grasses or floating plants often grows in 1 location during a wet year, another location during an intermediate year and not at all during a dry year.The debate has pivoted around the problem of devising management strategies that provide certainly for developers while protecting the ecological features of wetlands.
Say Who?
Some researchers have suggested that trees in the coastal mangrove swamps reach maturity at about 30yr of age, a periodicity that coincides almost perfectly with the frequency of hurricanes in the tropics.A wetland encompasses an array of shollow-water and saturated soil encironments that possess some elements of a terrestrial system and some of an aquatic system.Alterations in their water levels give rise to a series of ecological niches that can support terrestrial, partially aquatic and fully aquatic plants and animals.short-legged birds such as green-backed herons and limpkins feed along shallow-water shorelines.Longer-legged species, including egrets and great blue herons, feed in deeper water.
What If...?
What if rising and falling water levels is not only influence? rising and falling water levels is not only influence the internal character of a wetland, but they also link wetlands to 1 another and to other aquatic system.their sensitivity to water levels, wetlands are highly dependent on the quantity and quality of water in their immediate area.Wetlands bordering major lakes and streams may be less sensitive to such natural changes.Wetlands can serve as reprodutive or feeding sites for some species only if they are connected with other waterways.A sea wall or a dike at the landward boundary of a salt marsh can prevent the inland migration of the marsh when the sea level rises.
What Does This Remind Me Of?
This remind me of they arise in flat, tidally inundated but protected areas, such as salt marshes and mangrove swamps.Wetlands exist next to fresh-water rivers, streams and lakes and their floodplains.Wetlands comprise fresh-water marshes, potholes, meadows, playas and vernal pools where vegetation is not woody, as well as swamps where it is.Wetlands can also flourish on slopes and at the base of slopes, supplied by springs, and as bogs and fens fed by precipitation and groundwater.This anomalous feature of wetlands the way that short term destruction ansures long term gain is poorly understoof by the general public.Shifts in water levels serve to trigger nesting by wood storks in Florida and breeding by ducks in prairie potholes.