GCE Research Program

Program Overview

In GCE-I we began to describe the patterns of variability in estuarine processes with an emphasis on water inflow as a primary environmental forcing function. During GCE-II, we are continuing our focus on patterns of variability, but we are also working to elucidate the mechanisms that underlie this variation and in particular the extent to which gradients in water inflow drive landscape patterns. In so doing, we recognize the necessity of evaluating the interaction of inflow-driven changes with other factors that influence estuarine processes (i.e. geologic setting, organismal interactions, etc.). The central paradigm of GCE-II is that variability in estuarine ecosystem processes is primarily mediated by the mixture of fresh and salt water flow across the coastal landscape.

Conceptual models guiding GCE research. Left: Longitudinal perspective showing relative contributions of river discharge, groundwater flow, oceanic influence and net flow in three coastal sounds. Right: Lateral movement of water among subtidal, intertidal and upland habitats; A & B: river discharge and tidal flow combine to move water up and downstream, C: tidal exchange brings water on and off the marsh platform, D: precipitation, E: precipitation leads to overland flow (runoff) if soils are saturated or impermeable, F & G: groundwater may flow directly into the marsh or may transit under the marsh to emerge sub-tidally, H: evapotranspiration. By layering this model on top of the landscape model on the left, we will gain a more sophisticated understanding of spatial variation in ecosystem processes across the GCE landscape.

Research Questions from the GCE-II Proposal

Question 1: What are the long-term patterns of environmental forcing to the coastal zone? (more information)

Question 2: How do the spatial and temporal patterns of biogeochemical processes, primary production, community dynamics, decomposition, and disturbance vary across the estuarine landscape, and how do they relate to environmental gradients? (more information)

Question 3: What are the underlying mechanisms by which the freshwater-saltwater gradient drives ecosystem change along the longitudinal axis of an estuary? (more information)

Question 4: What are the underlying mechanisms by which proximity of marshes to upland habitat drives ecosystem change along lateral gradients in the intertidal zone? (more information)

Question 5: What is the relative importance of larval transport versus the conditions of the adult environment in determining community and genetic structure across both the longitudinal and lateral gradients of the estuarine landscape? (more information)

Research Projects

Many long-term core research projects and individual investigator studies have been initiated to address these over-arching research questions. A database of GCE research projects, including all associated personnel, study sites and research products (publications, data sets and reports), was recently developed and is currently being populated. Project descriptions can be accessed from links on corresponding research question pages (above), or from a list of all ongoing and complated projects here.