Our FCE I research focused on understanding how dissolved organic matter from upstream oligotrophic marshes interacts with a marine source of phosphorus (P), the limiting nutrient, to control estuarine productivity where these two influences meet-in the oligohaline ecotone. This dynamic is affected by the interaction of local ecological processes and landscape-scale drivers (hydrologic, climatological, and human). During FCE I, our ideas about how these "upside-down" estuaries (Childers et al. 2006) function has evolved, and we have modified our central theme to reflect this new understanding. Our focus in FCE II will be even more strongly on the oligohaline ecotone region of our experimental transects. For FCE II, our overarching theme is:
In the coastal Everglades landscape, population and ecosystem-level dynamics are controlled by the relative importance of water source, water residence time, and local biotic processes. This phenomenon is best exemplified in the oligohaline ecotone, where these 3 factors interact most strongly and vary over many [temporal and spatial] scales.
Hypothesis 1: Increasing inputs of fresh water will enhance oligotrophy in nutrient-poor coastal systems, as long as the inflowing water has low nutrient content; this dynamic will be most pronounced in the oligohaline ecotone.
Hypothesis 2: An increase in freshwater inflow will increase the physical transport of detrital organic matter to the oligohaline ecotone, which will enhance estuarine productivity. The quality of these allochthonous detrital inputs will be controlled by upstream ecological processes.
Hypothesis 3: Water residence time, groundwater inputs, and tidal energy interact with climatic and disturbance regimes to modify ecological pattern and process in oligotrophic estuaries; this dynamic will be most pronounced in the oligohaline ecotone.
Childers, D.L., J.N. Boyer, S.E. Davis, C.J. Madden, D.T. Rudnick, and F.H. Sklar, 2006. Relating precipitation and water management to nutrient concentration patterns in the oligotrophic "upside down" estuaries of the Florida Everglades. Limnology and Oceanography, 51(1): 602-616.