Coastal Wetland Ecology and Challenges for Environmental Management
Coastal wetlands are plant communities at the land-sea interface. Two common types of coastal wetlands are salt marshes and mangrove swamps. Marshes are dominated by nonwoody grasses and shrubs; mangrove swamps are dominated by trees.
The global distribution of salt marshes and mangroves is governed by temperature: most mangrove species cannot tolerate freezing temperatures, so they grow in warmer tropical and subtropical latitudes. Marshes are more common in cooler temperate latitudes.
Salt marshes and mangroves overlap in some subtropical regions; these areas may experience shifts in species composition in response to climate change. The dynamics and ecological consequences of these shifts are important topics for future research.
Plants in coastal wetlands are adapted for abiotic stressors including prolonged inundation, which causes soil anoxia, and high salinity.
Salt marshes exhibit predictable zonation patterns, where the distribution of species within a site varies with small changes in elevation. These zonation patterns are driven by species-specific adaptations to abiotic stressors and by interspecific competition. Zonation patterns in mangrove swamps are more variable.
Coastal wetlands provide a variety of ecosystem services to human communities: wetlands can improve water quality, store nutrients, and buffer against erosion and storm surge and provide nursery habitat for commercially and recreationally important fishery species.
Current management issues in coastal wetlands include encroaching suburban and agricultural development, sea level rise, nutrient enrichment and eutrophication from agricultural runoff and treated sewage discharge, and freshwater diversion.
The policies regulating development on coastal wetlands are complex and dynamic. Restoration is the most common approach to mitigate for anthropogenic impacts. An understanding of wetland ecology is crucial to making wise decisions concerning the nature and direction of restoration projects.
KeywordsSalt Marsh Storm Surge Coastal Wetland Mangrove Species Fiddler Crab
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