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 continued our focus on patterns of variability, but we elucidated the mechanisms that underlie this variation and in particular the extent to which gradients in water inflow drive landscape patterns (see GCE-II questions). The research proposed for GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape.

GCE-III Focus Areas

Area 1: Track long-term changes in climate and human actions in the watershed and adjacent uplands, and evaluate the effects of these drivers on domain boundary conditions (riverine input, runoff and infiltration from adjacent uplands, sea surface height). We will accomplish this through long-term measurements of climate, water chemistry, oceanic exchange, and human activities on the landscape. (more information)

Area 2: Describe temporal and spatial variability in physical (e.g. stratification, estuarine salt intrusion, residence time), chemical (e.g. salinity, nutrients, organic matter lability), geological (e.g. accretion) and biological (e.g. organism abundance and productivity) properties in the domain, and to evaluate how they are affected by variations in river inflow and other boundary conditions. We will accomplish this by tracking both water and marsh conditions at our core monitoring sites, remote sensing, and hydrodynamic modeling. (more information)

Area 3: Characterize the responses of three dominant habitats in the domain (Spartina marsh, fresh/brackish marsh, high marsh) to pulses and presses in salinity and inundation. We will accomplish this through monitoring, large-scale field manipulations, and modeling designed to evaluate system responses to changes in inundation in the Spartina marsh, increased salinity in the fresh/brackish marsh, and changes in hydrologic connectivity in the high marsh. We are particularly interested in determining thresholds that cause habitat transitions (state changes), and in identifying signals of these changes. (more information)

Area 4: Describe patterns of habitat provisioning and C sequestration and export in the GCE domain, and to evaluate how these might be affected by changes in salinity and inundation. We will accomplish this by using modeling and field observations to evaluate habitat provision and C flow under different scenarios of sea level rise, freshwater inflow, and coastal development that describe both the pre-colonial past conditions of the system and its likely future over the next 100 years. (more information)

Conceptual Model Guiding GCE Research

Conceptual model for GCE-III, showing longitudinal (left) and lateral (right) distribution
of habitat and water flows across the landscape.

Signature Publications

GCE Research Projects

Many long-term core research projects and individual investigator studies have been initiated to address components of 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.