Patterns of species distributions and ecological functions in landscapes are conditioned by disturbance histories, the drivers and pathways of which must be unraveled to assess sensitivity patterns and improve predictions of change. In South Florida, landscape patterns reflect biophysical legacies of continuous SLR since the end of the last glacial period, and of climate, hydrological, and land-use disturbances since the mid 1800s. Today, the location of the brackish groundwater mixing zone varies spatially and temporally, but we do not know the extent to which this variability is connected to changes in water management. We expand our program in a spatio-temporal context to associate climate and land-use changes, and their effect on the balance of fresh and marine water supplies, to legacies of change in the FCE system. By identifying patterns of response diversity to freshwater delivery at a landscape scale, this research will assume a critical role in establishing realistic goals for Everglades restoration in the face of SLR, as well as appropriate tools and approaches to achieve those ends. We seek to understand the temporal and spatial scales, as well as the nonlinear relationships, by which global and regional drivers produce change in the coastal ecotone. We will conduct retrospective analyses to examine the interplay of climate and land-use change in changing saltwater intrusion rates, which feed back to determine both Everglades function in the natural landscape and the trends and vulnerability of resource utilization and distribution in the urban-agricultural gradient. We will link landscape structure, connectedness, and boundaries with land-water management dynamics to assess the sensitivity of the socio-ecological system within the framework of global and regional drivers. The FCE III will investigate legacies of water policy regimes and their consequences at the landscape scale, and generate empirical input for modelers to explore possible futures of land-water use decisions and impacts.