Research Theme 1- External Drivers

What drivers control the geomorphic features and spatial arrangement and connectivity of habitat patches in the coastal zone?

A number of drivers may exert control on the shape of the coastal landscape. These include external, climate-related forces such as temperature, precipitation, storms, and sea level rise that provide the backdrop upon which internal processes operate.

Climate change assessments for the northeast document an increase in extreme precipitation events, especially during winter:

“The Northeast has experienced a greater increase in extreme precipitation over the past few  decades than any other region in the U.S.; between 1958 and 2010, the Northeast saw a 74% percent increase in the amount of precipitation falling in very heavy events.”  (NCAJan11-2013-publicreviewdraft-chp16-northeast.pdf).

A review of storm frequency at LTER sites is in agreement with these findings, showing an increase in the number of storms per year at the Plum Island LTER beginning around 1950 (Hayden and Hayden 2003).  In contrast, the risk of warm season drought is projected to increase due to rising temperatures.  Having identified hydrology as an important influence on ecosystem response at PIE,  it is clear that these changes may have an important impact on system function, impacting water and material transport, habitat connections, and salinity-sensitive biological processes. 

The average rate of sea level rise for the northeast is 3-4 times higher than the global average; in fact, this region has been termed a “sea level rise hot spot” in a recent analysis (Sallenger et al 2012),  partly due to land subsidence and also related to changes in Gulf Stream circulation.  The rate of sea level rise has implications for survival of PIE marshes, and together with changing storm energy, on eroision of beaches and creekbanks.  

We use monitoring data from PIE research in conjunction with regional databases to assess local patterns in these drivers.

Temperature and Precipitation: Meterological stations based at the campus of Governor’s Academy and the PIE LTER Marshview Farm Field Station within the Parker River watershed have provided air temperature and precipitation data since year 2000. Coupled with historical data these long term records will enable researchers to evaluate changes in local weather patterns and possible linkages to climate drivers.

          

Sea level: Sea level is monitored at NOAA Stations to the southof PIE in Boston, MA (below) and to the north  in Portland, ME.  At Boston, the rate of sea level rise for the period of record (1921-2012) was 2.79 mm yr-1, and at Portland (1912-2012) was 1.90 mm yr-1. Although PIE is geographically between these these two, sea level rise at PIE may not be. To get a site-specific measurement, we have recently installed a water level monitoring station at the Ipswich Bay Yacht Club, near the mouth of Plum Island Sound.  This station will also add to the local SL monitoring network.