The US Geological Survey, Southeast Ecological Science Center (SESC), is officer a funding opportunity for research on the effects of global climate change (GCC) and sea level rise (SLR) on coastal vegetation, including transitions from freshwater vegetation communities to communities associated with more marine or brackish conditions. This will be a consequence not only of gradual SLR, but also of storm surges that can deposit large amounts of saline water far inland and possibly trigger major regime shifts to more salinity-tolerant vegetation. A model currently exists to examine mangrove/ hammock interaction and regime shift (the MANHAM model, Sternberg et al. 2007, Teh et al. 2008) and has been used for projecting ecotone movement and changes in salinity. This model demonstrates that acute increases in salinities of the vadose zone, induced by storm surge overwash events, might reduce the growth rate of the salinity intolerant hardwood hammock trees. This could promote regime shifts toward mangroves at sites that are far inland, but reachable by storm surges. This model does not take into account some features of the environment, such as groundwater dynamics, however, and needs to be improved and broadened.