Plum Island Ecosystems LTER Database

Acceptance and utilization of LTER data requires that:

(1) The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
(2) The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
(3) A copy of any resultant publications should be sent to:

Principal Investigator
Ecosystems Center
Marine Biological Laboratory
7 MBL St.
Woods Hole, MA 02543

Dataset URLs:METADATA: HTML, Rich Text, XML(EML compliant)
DATA: Comma Delimited, Excel file with Metadata and data
Dataset ID:LTE-MP-porewater.08
Dataset Title:Nutrient concentrations from porewater samples at three marsh fertilization experimental research sites.
Investigator 1: 
First Name:Jim
Last Name:Morris
Address line 1:Dept of Biological Sciences
Address line 2:
Address line 3:University of SC
Zip Code:29208
Investigator 2: 
First Name:Karen
Last Name:Sundberg
Address line 1:Baruch Marine Field Laboratory
Address line 3:PO Box 1630
Zip Code:29442
Associate Investigators:Robert Daoust, Helen Marshall, Diana Rodriguez
Keywords:PIE LTER, Plum Island Ecosystems, Massachusetts, Rowley River, Parker River, inorganic nutrients, porewater, salt marsh, nutrient cycling, ammonium, phosphate, Typha, Spartina
Abstract:Nutrient concentrations from porewater samples at three long term marsh fertilization experimental research sites. The sites include one Typha-dominated brackish marsh, one Spartina alterniflora-dominated salt marsh, and one S. patens-dominated salt marsh. Sites are located on the Rowley and upper Parker Rivers in the Plum Island Ecosystem (PIE) LTER site.
Contact: Plum Island Ecosystems LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7485
Online URL:
Data File URL
Data File Name LTE-MP-porewater
Beginning Date 7/1/1999
End Date 9/30/2012
Number of Data Records 5970
Other Files to Reference
Availability Status type 1
Quality Control Information
Maintenance Description Collections occur every month from May through October. Database is updated once annually, usually in the winter. Study and data collection are ongoing as of Dec 2012.
Log of Changes: Version 01: July 11, 2006 Level 3+ EML using Jim laundre's Excel program
Version 02: January 10, 2007 data and metadata update
Version 03: March 12, 2008 Data and metadata update
Version 04: February 20, 2009 Data and metadata update
Version 05: January 13, 2010 Data and metadata update
Version 06: October 25, 2011 Data and metadata update
Version 07: January 12, 2012, 2011 data and metadata update, using MarcrosExportEML_HTML (working)pie_excel2007.xlsm 1/12/12 11:51AM for QA/QC to EML 2.1.0
Version 08: March 14, 2013, 2012 data and metadata updated to comply with importation to Drupal and LTER PASTA. Research location name and description updated.Used MarcrosExportEML_HTML (working)pie_excel2007.xlsm 3/14/13 12:02 PM for QA/QC to EML 2.1.0
Geographic Description Law's Point on Rowley River, Rowley, MA, site of PIE LTER Spartina alterniflora plot level fertilization experiment. Law's Point on Rowley River, Rowley, MA, site of PIE LTER Spartina patens plot level fertilization experiment Upper Parker River off Orchard St., Newbury, MA, Typha sp. plot level fertilization experiment  
Location Bounding Box        
West Bounding Coordinate        
East Bounding Coordinate        
North Bounding Coordinate        
South Bounding Coordinate        
OR if single point location        
Latitude 42.731742 42.730954 42.756738  
Longitude -70.842472 -70.842915 -70.917717  
Taxonomic Protocols
Organisms studied Typha; Spartina alterniflora; Spartina patens
This data set is part of a study including three on-going plot-level fertilization sites. The first (LTE-MP-LPA) is in the low marsh at Law's Point along the Rowley River. The second (LTE-MP-LPP) is in the high marsh at Law's Point along the Rowley River. The third (LTE-MP-ORT) is in a brackish water marsh on an upstream tributary of the Parker River. Porewater samplers were established at LTE-MP-LPA in Jun 1999, at LTE-MP-LPP in Aug 2000 and at LTE-MP-ORT in Jun 2000.

At each site a system of boardwalks was built to incorporate 12 experimental plots (1m2 each). There are 4 treatments (three reps each) within the boardwalk structure. The 4 treatments are Control, N-fertilized, P-fertilized, N+P fertilized. Additionally, at each site there are 3 control plots and 3 N+P fertilization plots external to the boardwalk structure. These external plots contain porewater samplers, and, in some cases, biomass census plots. In May 2006 the control porewater plots and control census plots at all three sites were moved because of potential contamination from fertilized plots.

Fertilizer is buried at several locations within each plot, monthly, from May-Sept. From 1999-2001 the annual fertilization rate was 30 molN/m2/y and 15 mol P/m2/y. From 2002 to present fertilization rate is 7.5 mol N/m2/y and/or 3.75 mol P/m2/y. N fertilizer was NH4NO3 through 2008, and currently is nitrate/urea/sulfate (34-0-0). P fertilizer is P2O5 (0-44-0).

Sampling Description:
Triplicate porewater diffusion samplers are permanently installed in fertilized (30 mol N/m2/y and 15 mol P/m2/y through 2001; 7.5 mol N/m2/y and 3.75 mol P/m2/y beginning in 2002) and control plots at each of the three research sites. Each sampler collects porewater from depths of 10, 25, 50, 75, and 100 cm. Samples are retrieved approximately monthly from May through October. Porewater samples are filtered (0.2 uM) and preserved with either ZnAc (for sulfides) or acidified to pH<2 (for SRP and NH4) immediately upon return from the field. These samples are then shipped to the lab in SC for analysis.

Lab Methods:
Filtered porewater samples are analyzed for SRP and NH4 on a Bran+Luebbe AutoAnalyzer according to standard laboratory protocols (Strickland and Parsons (1972)). Samples are analyzed for Sulfide following the method of Cline (1969) L&O 14: 454-456. Chloride concentrations are measured on a Haake Buchler Chloridometer. Salinity is calculated from chloride concentrations.

Data Table

Variable Name Variable Description Units Measurement Scale Code Information Number Type DateTime Format Missing Value Code Missing Value Code Explanation
SITE current name of sampling station, following naming protocol   nominal          
YEAR year   datetime     yyyy    
MONTH month   datetime     mm    
TRT treatment   nominal NP=fertilized | C=control        
REP porewater sampler replicate number   nominal          
DEPTH depth (cm) centimeter ratio   real      
SRP soluble reactive phosphorus concentration (uM SRP) micromolePerLiter ratio   real   . | BD .=not measured | BD=below detection
NH4 ammonium concentration (uM NH4) micromolePerLiter ratio   real   . | BD .=not measured | BD=below detection
S2 sulfide concentration (uM S-2) micromolePerLiter ratio   real   . | BD .=not measured | BD=below detection
Cl chloride concentration (g Cl/l) gramPerLiter ratio   real   . | BD .=not measured | BD=below detection
SALINITY salinity (ppt) partPerThousand ratio   real   . | BD .=not measured | BD=below detection