Geographical Trends in Ecosystem Function and Biodiversity of Wetlands as a Surrogate for Climate Change

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Extreme drought and temperature in the southeastern United States may become more frequent in the future, and any  extreme shifts in climate condition are likely to have effects on wetland ecosystem function. USGS research predicts the effects of climate change by shifts in function and biodiversity across existing  climate gradients in baldcypress swamps. 

Geographical Trends in Ecosystem Function and Biodiversity of Wetlands as a Surrogate for Climate Change
North American Baldcypress Swamp Network is a long-term study network throughout the Southeastern United States. 
The Science Issue and Relevance: Extreme drought and temperature in the southeastern United States may become more frequent in the future according to the International Panel on Climate Change. Any extreme shifts in climate condition are likely to have effects on wetland ecosystem function. Therefore, this study predicts the effects of climate change by shifts in function and biodiversity across existing climate gradients in baldcypress swamps. Production and regeneration of swamps in the southwestern part of the range already may be stressed and, therefore, most vulnerable to climate change. In addition, coastal swamps are vulnerable to high salinity, so that fresh water management may be helpful.

Methods for Addressing the Issue: These studies are conducted in the North American Bald Cypress Swamp Network (NABCSN), which is a long-term study network located throughout the southeastern United States along the Mississippi River Alluvial Valley from southern Louisiana to southern Illinois, and the Gulf and Atlantic Coasts from Texas to Florida and Maryland/Delaware, respectively (70 wetlands total). The network has replication at the landscape level, with five replicate swamps per geographical area.

Within each wetland, production, growth and regeneration are studied. Annual estimates include above- and below-ground production, decomposition, soil carbon content, tree growth, and seed banks. Environmental measurements include water, sediment, and salinity dynamics; many sites have water-level recorders and Sediment Elevation Tables.

Future Steps: The project will construct models of climate change responses in freshwater swamps. Managers use the information to design water management strategies to minimize the loss of biodiversity and maximize health of coastal and inland forests. Results of this study are used to construct water management plans in southern Illinois and eastern Texas.

Related Projects: Modeling the connections between surface and groundwater hydrology, water quality, and ecosystem health to support coastal preservation efforts across the Northern Gulf Coast; Damage, resilience and change thresholds of forest (maritime, cypress) and barrier island vegetation of the Delmarva Peninsula following Hurricane Sandy; Collaborative geographic studies on methane emission, and genetic variation.