Long-term core measurements are designed to detect long term changes in major drivers (climate, sea level), material stocks and fluxes (water, nutrients, carbon, sediment), and key biotic (primary production, food web, biogeochemical cycling, respiration) and abiotic (sedimentation, porewater drainage) responses.
Climate and Sea Level
Meteorological data are available from a weather station located at the Marshview Field Station (PIE LTER weather stations), wind sensors at the Ipswich Bay Yacht Club pier in Ipswich, MA and eddy covariance flux towers in salt marshes in Newbury, MA (PIE LTER Eddy Flux Stations).
Water level is monitored throughout the Plum Island estuary (PIE LTER Water Level Stations) using a variety of instruments. Open water column level data are available at water quality stations: Ipswich Bay Yacht Club pier, Rt 1A Parker River and Middle Road Parker River. Marsh sediment water level data are available for Spartina and Typha marshes in the Parker River.
Above ground biomass and productivity of Spartina alterniflora and S. patens are monitored as control sites within a long-term plot-level marsh fertilization experiment. Water column primary production (based on dawn-dusk O2 fluxes) and chlorophyll a concentrations are collected during semiannual transects of the Parker River Estuary. Benthic chlorophyll a data are available for selected subtidal sites in the Parker R. Long term data sets for vegetation transects are also available for several sites. [Primary Production Data]
Organic matter gains and losses in the marshes are being monitored several ways. Most recently, instrumented towers are providing year-round monitoring of CO2 fluxes. Sediment Elevation Tables (SETs) installed throughout the marsh are monitored semi-annually, or annually in spring. Depths of feldspar marker horizons are measured at the same time. Long-term records of carbon and sediment deposition are also obtained as 210Pb profiles from marsh sediment cores. [Organic Matter Data]
Numerous long-term datasets describe nutrient concentrations and dynamics from the watershed, estuary, and marshes. They include data from repeated grab samples at dams discharging to the estuary, automated sampling of streams in the watersheds, transect sampling in the rivers and the estuary, porewater monitoring in the marshes, and nutrient fluxes from subtidal sediments. Additional long-term data on nutrients are associated with fertilization experiments as well as productivity and biomass measurements. [Inorganic Nutrient Data]
Long term monitoring of PIE populations has included direct counts of organisms (for example fish, invertebrates, birds) as well as by using indicator measurements such as stable isotopes of C, N, and S, and in the case of phytoplankton, pigment analyses. We also make use of census data collected by others on species of commercial and/or conservation interest, such as Striped Bass and herring. [Population Dynamics Data]