Intellectual Merit: The Plum Island Ecosystems (PIE) LTER has, since its inception in 1998, been working towards a predictive understanding of the long-term response of coupled land-estuary-ocean ecosystems to changes in three drivers: climate, sea level, and human activities. The Plum Island Estuary-LTER includes the coupled Parker, Rowley, and Ipswich River watersheds, estuarine areas including a shallow open sound, and extensive tidal marshes. PIE is connected to the Gulf of Maine in the Acadian biogeographic province, which is a cold water, macrotidal environment that is geographically and biologically distinct from coastal ecosystems to the south of Cape Cod, Massachusetts.
Over the next four years the LTER will build upon the progress they have made in understanding the importance of spatial patterns and connections across the land-margin ecosystem. The overarching goal is to understand how external drivers, ecosystem dynamics, and human activities interact to shape ecological processes in a mosaic of coastal landscapes and estuarine seascapes. Understanding how landscapes and seascapes evolve and change, and how those changes control ecosystem processes, is both a fundamental science question and a critical management question. During the remainder of PIE III LTER researchers will continue to address the role of temporal change and variability in climate, sea-level rise and human activities on ecological processes in our long-term monitoring but they will also initiate new activities that examine spatial arrangements and connectivity. LTER research questions are focused around two themes: 1) What controls the spatial arrangements and connectivity between ecological habitat patches in the coastal zone? 2) How do the spatial arrangement and the connectivity between ecological habitat patches in coastal watersheds and the estuarine seascape influence ecological processes?
To address their goal researchers will: 1) Quantify recent changes in spatial arrangements and connectivity in the watershed and estuary and investigate their drivers. 2) Supplement long-term monitoring with additional measurements in the watershed and estuary to understand how ecosystem processes are influenced by different spatial arrangements and connectivity. In the watershed these include areas where the river network has been modified by suburbanization and beaver dams. In the estuary LTER investigators will examine feedbacks between form and function in contrasting areas that appear to be responding very differently to sea-level rise; in one case maintaining the marsh platform and in another losing marsh area, forming ponds and transitioning to a lower elevation. 3) Continue existing and add new large scale manipulative experiments to increase mechanistic understanding of ecological processes in various critical land and seascape patches and their responses to drivers. 4) Develop and apply models to understand how biogeochemical and trophic processes emerge at broader scales in a spatially complex coastal environment.
Long-term data collection, however, will remain a central activity as many of the hypotheses, as to the importance of geomorphic change to ecosystems processes, have come from our observations that spatial arrangements and their connections at PIE are rapidly changing, on the time scale of decades. Further, the LTER continues to expand efforts to understand how management decisions are influenced by both geomorphic and ecosystem changes. These interactions and feedbacks are important drivers of change at PIE and as a consequence LTER researchers have increasingly integrated human activities within the PIE conceptual framework.
Broader Impacts: The LTER K-12 schoolyard program, "Salt Marsh Science", serves over 1,000 students in grades 5-12 in ten schools and the LTER hopes to continue to expand this into more schools. LTER education coordinator, Ms. Duff, has co-founded an effort to eradicate perennial pepperweed that involves over 1000 students and adults. This effort has attracted regional attention and partners. The LTER serves college undergraduates through internships, research projects and field trip. REU opportunities for undergrads exist through the PIE-LTER, the NSF funded Clark "HERO" program, the MBL-Brown partnership, and the U. of New Hampshire. The LTER will continue the collaboration with the MBL-Brown IGERT Program, where graduate students are exploring the intersection between modern genomics and ecosystems science. Outreach is an important part of the PIE LTER mission and includes inter-LTER efforts and participation in the MBL's science journalism program. The LTER has close connections with nearly all of the management agencies and NGOs in the region and LTER researchers serve on many advisory boards. All data collected by the PIE LTER are centralized and made available though a web site.
