General:
This data set is part of an on-going LTER project at the Plum Island Ecosystem (PIE) site. The sampling location is in a Spartina patens-dominated marsh at Law's Point between the Rowley River and West Creek in Rowley MA.
Sampling Description:
The biomass-estimation method is destructive. Three control plots were permanently established in the marsh. For sampling, a 10x10 cm quadrat is placed randomly in each plot, and all plants are clipped within 1 cm of the sediment surface and placed into a labelled plastic bag for transport to the lab. Live and dead plants are separated, and live plants are separated by species. Plants are placed into labelled paper bags, dried at 60C and weighed. Sampling occurs approximately monthly from May to October.
Permanent census plots were established in August 2000. The first complete year of data available for annual productiviy is 2001. In May 2006 the plots were moved due to potential contamination from nearby fertilized plots.
Data processing:
All data are entered into an Excel spreadsheet. Annual productivity is determined using a variation of the Smalley method and SAS (SAS System for Windows; release 8.02; SAS Institute, Inc; Cary, NC), and is based on standing live+dead biomass at peak live biomass for the year of interest. Data are reported as the mean annual productivity and standard error of the 3 plots (n=3).
Elevation: LTE-MP-LPP, ~ 1.4 meters NAVD88