A Continuum of Connectivity: Geographically Isolated Wetlands and the Conservation of Landscape Functions

Thursday, 18 December 2014: 12:05 PM
Matthew J Cohen, Univ Florida-SFRC, Gainesville, FL, United States, Irena F Creed, University of Western Ontario, London, ON, Canada, Nandita B Basu, University of Waterloo, Waterloo, ON, Canada, James W Jawitz, University of Florida, Soil and Water Science, Ft Walton Beach, FL, United States, Daniel L Mclaughlin, Virginia Polytechnic Institute and State University, Forest Resources and Environmental Conservation, Blacksburg, VA, United States and Mark Cable Rains, Univ South Florida, Tampa, FL, United States
Landscape functions depend on how matter, energy, and organisms exchange between elements in hydrologic and habitat networks. Wetlands are important network elements, providing hydrological, biogeochemical and biological functions that vary along a continuum of connectivity with nearby and downstream waters. Geographically isolated wetlands (GIWs), those surrounded by uplands, occupy the entire connectivity continuum, but generally fall outside US legal protections unless a “significant nexus” to navigable waters is demonstrated. Geographic isolation does not imply hydrological, biogeochemical or biological isolation. Here we show multiple lines of evidence to support the inference that GIWs are integral to the function of navigable waters. Moreover, while GIW hydro-chemical connectivity may be episodic or slow (e.g., via groundwater), and biological connectivity limited by overland dispersal, reducing material or organism exchange is specifically what enables important, sometimes unique, functions. This relational connectivity, wherein precluded exchange creates functionality, may be as important to downstream waters as more obvious connections. Logic and evidence support the presumption that anthropogenic changes to GIW prevalence, condition and connectivity have significant downstream impacts.