The Plum Island Ecosystem (PIE) is the latest of the NSF's Long Term Ecological Research (LTER)sites. The project is headed by Chuck Hopkinson (Ecosystems Center, MBL, Woods Hole) and involves investigators from four institutions. My lab has the responsibility of developing a long-term data base that describes the structure and function of intertidal marshes around the Plum Island Estuary, in Massachusetts. We want to understand the functional interrelationships between the intertidal wetlands and the estuary proper. We will contrast the functions of North Inlet (warm temperate) and Plum Island (cold temperate) marshes. We will monitor production, sedimentation, and sediment chemistry in control and experimentally fertilized sites to contrast with those already in place in North Inlet. We also are examining the changes in biogeochemical properties of sediments along the estuarine salinity gradient.

Graduate students Weihong Wang and Whitney Pate pose next to a 'marsh organ' planted with Spartina alterniflora in spring 2006 before the plants had put on much new growth. In this experiment we will determine the response of the plants to the elevation of the marsh surface relative to mean sea level. We expect that the growth of the plants in these PVC pipes will differ among the rows. By the end of the growing season the plants will grow to a large size. The PVC pipes are open on the bottom to allow vertical drainage. The tidal pond in which the marsh organ rests was most likely created by ice rafting. The detritus or plant debris on the marsh surface is from plant production during the previous growing season. These dead stems will disapear as the summer progresses.

A second objective will be to determine if anomalies in sea level affect the productivity of the marsh plants at Plum Island Sound. At North Inlet we have observed that interannual changes in mean sea level have a large effect on primary production. The Plum Island Sound study will reveal whether this phenomenon is common and synchronous. If the changes in productivity are synchronous across the east coast, then the changes in production and sea level could have broad-scale effects, such as an impact on fisheries or coastal water quality.