LTER: Georgia Coastal Ecosystems V

About This Grant

The Georgia Coastal Ecosystems (GCE) Long Term Ecological Research (LTER) program, which was established in 2000 to understand estuaries (places where salt water from the ocean mixes with fresh water from the land) and their adjacent coastal wetlands (i.e., marshes and tidal forests) and how they respond to long-term change. The GCE LTER researchers evaluate how environmental conditions (e.g., sea level, temperature, storms and hurricanes) and human activities (e.g., land use) affect the properties of estuaries (e.g., salinity, flooding patterns), and how that in turn affects wetlands and their ability to provide food and refuge for fish, shellfish and birds, to protect the shoreline from storms, to help to keep the water clean, and to store carbon, all of which have significant implications for the US economy. Many of the changes that are occurring are affecting not just average conditions, but also their fluctuations and extremes (e.g., variability). For example, not only has the average high tide level increased over the past decade, but the number of extreme flooding events has also increased, both of which have the potential to lead to wetland loss through drowning. During this award, the research team will conduct studies to systematically evaluate 1) whether we can improve our predictions of ecological responses by considering variability in environmental conditions, and 2) the use of variability as an early indicator of underlying environmental stress. The findings from this research will be important for predicting the long-term survival of coastal wetlands in a time of global change. In addition to research, the GCE program works with teachers and students, coastal managers, citizen scientists, and the general public to enhance scientific literacy and improve our understanding of coastal ecosystems. The GCE LTER is based at the University of Georgia Marine Institute on Sapelo Island, Georgia, and has a robust program of long-term field observations, experiments, remote sensing, and modeling designed to understand wetland ecosystem functioning. GCE LTER researchers will build on this foundation with an overlay of new efforts focused on variability. Objective (Obj) 1 is to characterize spatial and temporal patterns in mean and variability of drivers and responses by measuring external drivers (e.g., sea level), marsh and estuarine conditions, and the wetland biophysical template, and to integrate these dynamics via modeling. Obj 2 is to evaluate linkages between external drivers and ecological responses, and determine whether assessing the variability of abiotic drivers improves predictions of those responses. This will be done by analyzing long-term data, conducting field campaigns in areas with different variability in salinity and inundation, and conducting complementary mechanistic experiments to quantify the effects of driver variability (e.g., salinity). Obj. 3 is to assess disturbances and their effects on patterns of variability in ecological responses by tracking the effects of natural disturbances in the field along with ongoing experimental manipulations. Obj. 4 is to evaluate how ecological properties change across abiotic gradients, and determine whether variability increases near habitat transitions. This will be done using remote sensing, sampling across gradients of salinity and inundation, and establishing long-term monitoring sites in forested areas to track upland marsh migration. Obj. 5 is to determine the mechanisms by which coastal wetlands respond to changing drivers and assess whether variability informs this understanding. This will be done in three ways: by conducting statistical analyses relating key ecosystem variables (e.g., net ecosystem exchange, plant biomass) to drivers (salinity, inundation, temperature); by using remote sensing to investigate spatial and temporal patterns in the mean and variability of marsh productivity and their relationship to variability in climate drivers; and by synthesizing results to describe net daytime production and C stocks and predict how they might change in response to future conditions. The GCE education and outreach program will provide K-12 teachers with research experience that can be shared in the classroom, along with school visits. It will offer research opportunities through undergraduate internships, and run web-based courses for graduate students. The program will initiate a citizen science effort to delineate high tide flooding events, and will partner with the Georgia Coastal Research Council to exchange information with coastal managers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.