Sea level rise and South Florida coastal forests

Coastal ecosystems lie at the forefront of sea level rise. We posit that before the onset of actual inundation, sea level rise will influence the species composition of coastal hardwood hammocks and buttonwood (Conocarpus erectus L.) forests of the Everglades National Park based on tolerance to drought and salinity. Precipitation is the major water source in coastal hammocks and is stored in the soil vadose zone, but vadose water will diminish with the rising water table as a consequence of sea level rise, thereby subjecting plants to salt water stress. A model is used to demonstrate that the constraining effect of salinity on transpiration limits the distribution of freshwater-dependent communities. Field data collected in hardwood hammocks and coastal buttonwood forests over 11 years show that halophytes have replaced glycophytes. We establish that sea level rise threatens 21 rare coastal species in Everglades National Park and estimate the relative risk to each A. K. Saha Southeast Environmental Research Center, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA S. Saha (B) The Institute for Regional Conservation, 22601 SW 152nd Ave., Miami, FL 33170, USA e-mail: [email protected] J. Sadle Everglades National Park, 40001 State Rd. 9336, Homestead, FL 33034-6733, USA J. Jiang · L. S. L. O. Sternberg Dept. of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33124, USA M. S. Ross · R. M. Price Southeast Environmental Research Center and Dept. of Earth and Environment, Florida International University, OE 148, Miami, FL 33199, USA K. S. Wendelberger Curriculum for the Environment and Ecology, University of North Carolina, Chapel Hill, 207 Coates Building CB# 3275, Chapel Hill, NC 27599-3275, USA 82 Climatic Change (2011) 107:81–108 species using basic life history and population traits. We review salinity conditions in the estuarine region over 1999–2009 and associate wide variability in the extent of the annual seawater intrusion to variation in freshwater inflows and precipitation. We also examine species composition in coastal and inland hammocks in connection with distance from the coast, depth to water table, and groundwater salinity. Though this study focuses on coastal forests and rare species of South Florida, it has implications for coastal forests threatened by saltwater intrusion across the globe.