Intellectual Merit: The Plum Island Ecosystems (PIE) LTER is an integrated research, education and outreach program whose goal is to develop a predictive understanding of the long-term response of watershed and estuarine ecosystems at the land-sea interface to changes in climate, land use, and sea level. The principal study site is the Plum Island Sound estuary located in the Acadian biogeographic province in eastern New England. The study sites include the coupled Parker, Rowley, and Ipswich River watersheds, their tidal marshes, and the surrounding ocean of the Gulf of Maine. Land use change and urbanization of coastal watersheds are altering both the magnitude and timing of the flow of materials and water to coastal ecosystems. These changes in flows from land, coupled with climate change and sea level rise, will have important, but still poorly understood consequences for the ways in which materials and energy are transformed in the coastal zone. It will also have important consequences for the people who value these ecosystems for food, recreation, and storm protection. The overarching question of this project addresses the ecological consequences of global change in the coastal zone: How do external drivers, ecosystem dynamics, and human activities interact to shape organic matter and nutrient transformations in linked watershed and coastal ecosystems?
This project follows from prior LTER studies of biogeochemistry, food webs, and population biology in the Plum Island watersheds, estuary, and intertidal marshes. In this next phase of PIE LTER research there will be more emphasis on linkages and feedbacks between the component ecosystems, including the human dimension. LTER Researchers will also place a greater emphasis on the role of geomorphology and geomorphic change in ecosystem dynamics. To organize this research the investigators have divided the study into four programmatic areas, each of which addresses an issue critical to answering our overarching question:
Q1 Watersheds – How do human alterations of inter-basin material transfers, within-basin ecosystem connectivity, and geomorphology interact with climate to impact ecosystem regulation of water, organic matter, and nutrient fluxes through the watershed to the estuary, and how do these changes feed back to human behaviors that further alter watershed function?
Q2 Marsh – Are the relative elevations of salt marshes at PIE in equilibrium with sea level, and if not, what are the consequences for primary production, biogeochemical cycling, and material exchanges between the marsh and estuary?
Q3 Estuary – How do human activities and variations in climate that affect the coupling with watersheds, intertidal marshes, and the ocean shape organic matter and nutrient transformations in estuarine tidal creeks and bays?
Q4 Higher Trophic Levels – What are the consequences of changes in ecosystem spatial configuration and dynamics for the structure and transfer of productivity in food webs, and for the function of higher trophic levels in estuarine ecosystems?
To address these questions LTER Researchers will use a combination of approaches: 1) the collection of long-term data on key ecosystem drivers and ecosystem responses, 2) short and long-term experiments, 3) comparative ecosystems studies, and 4) modeling. All data collected by the PIE LTER will be centralized and easily accessible to PIE-LTER scientists, local, regional and state partners, and the broader scientific community.
Broader Impacts: The educational and outreach program at PIE LTER is greatly strengthened through partnerships with local educators and NGOs. LTER personnel will continue to collaborate with Massachusetts Audubon and the Governor’s Academy for the LTER schoolyard program, which has brought hands-on science training to students in grades 5-12. “Salt marsh Science” currently serves more than 1000 students and 50 teachers a year. Over the next six years the LTER plans to expand teacher training, and include a focus on environmental stewardship. Undergraduates will be served by intensive research experiences focusing on individual projects under the mentorship of PIE scientists. Both undergraduate and graduate student involvement will increase with the addition of new PIs. PIE will maintain an active outreach program through collaboration with many local and regional NGOs including the Gulf of Maine Institute, Essex County Greenbelt, the Ipswich River Association, and the Parker Clean Water Association. PIE scientists help bring scientific information into policy by serving as advisors to policy makers at the local, state, and national level, a role that continues to grow.
