Porewater is sampled monthly from May through December. Samples are retrieved from seven diffusion sampling poles at four sites, Railroad and Typha, along the Parker River and Shad and Nelson, along the Rowley River. At each site, one pole is located 4 m from creek edge and another pole is 10 m from creek edge. Nelson also has a pole 75 m from the creek. Samples are retrieved at depths of 10, 25, 50, 75, and 100 cm, and are filtered and partitioned for analysis. Nitrate, NH4, DOC, TDN and H2S concentrations are measured in each sample according to standard laboratory protocols, and salinity is measured using a conductivity probe. Beginning in 2017 sulfide (H2S) is also measured from each site. Analyses are conducted according to PIE-LTER protocols (http://ecosystems.mbl.edu/pie/data/method.htm).
The Shad, Nelson and Railroad sites are dominated by Spartina sp and the Typha site is dominated by Typha sp.
NOTES AND COMMENTS:
Phosphate was only measured for some 2004 samples.
Sites at Nelson (high marsh 1.3m NAVD88) and Shad (low marsh 1.1m NAVD88) were added in 2017.
Only the 4m sites at Typha and Railroad are measured starting in 2017.
Samplers are located in the same place each year.
New sites GPSed in 2018
Site Elevation (m) Latitude Longitude
Nelson 4m 1.086 42.7419505 -70.8308365
Nelson 10m 1.441 42.7420214 -70.8308159
Nelson 75m 1.439 42.7426213 -70.8307631
Shad 4m 1.169 42.7344157 -70.8380359
Shad 10m 1.065 42.7344368 -70.8381692
