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-LPA-biomass.12
Dataset Title:Aboveground biomass of Spartina alterniflora at Law's Point salt marsh on the Rowley River.
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, primary production, inorganic nutrients, aboveground biomass, salt marsh, nutrient cycling, Spartina alterniflora
Abstract:Aboveground biomass is determined non-destructively during the growing season at a Spartina alterniflora-dominated salt marsh on the Rowley River within the Plum Island Ecosystems (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-LPA-biomass
Beginning Date 6/1/1999
End Date 10/31/2016
Number of Data Records 204
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 2016.
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, Day variable name removed from data set
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, 2010 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
Version 09: April 18, 2014, 2013 data and metadata updated to comply with importation to Drupal and LTER PASTA.Used MarcrosExportEML_HTML (working)pie_excel2007_Sep2013.xlsm 9/30/13 02:57 PM for QA/QC to EML 2.1.0
Version 10: February 11, 2015, data and metadata updates to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007_Jan2015.xlsm 1/15/15 4:26 PM for QA/QC to EML 2.1.0
Version 11: February 24, 2016, data and metadata updates to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007_Jan2015.xlsm 1/15/15 4:26 PM for QA/QC to EML 2.1.0
Version 12: September 20, 2017, data and metadata updates to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007_Jun2017.xlsm 6/15/17 10:23 AM 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.  
Location Bounding Box    
West Bounding Coordinate    
East Bounding Coordinate    
North Bounding Coordinate    
South Bounding Coordinate    
OR if single point location    
Latitude 42.731742  
Longitude -70.842472  
Taxonomic Protocols
Organisms studied Spartina alterniflora
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. Biomass sampling is slightly different at each site, and is accomplished non-destructively at the LTE-MP-LPA and LTE-MP-ORT sites, and destructively at the LTE-MP-LPP site. Biomass sampling at LTE-ME-ORTwas discontinued after August 2008.

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:
The plant census method at LPA is non-destructive. Two permanent subplots were established in each plot within the boardwalk. Each subplot is 10cmx10cm. The subplots are labeled 1&2, with subplot 1 being the more northerly and/or westerly subplot. In May and June, plants in the subplots are tagged with bird ID bands. Approximately monthly from May to October, heights of the tagged plants and associated culms are measured to the nearest cm. Plant heights are read into a digital recorder. Descriptions of the locations of the plants within the quadrat are also recorded (e.g. northwest corner or northwest of tag #xxxx). Plant measurements are always taken with the observer on the same side of the quadrat for ease in tracking plants throughout the growing season.

The plant census at LPA began in June 1999. All 24 subplots were censused until October 2003. Beginning in May 2004, only the 6 C subplots were censused. In May 2006 the C census plots (and porewater samplers) were relocated further away from the boardwalk structure. The census subplots kept the same id#ís from when they were within the boardwalk for continuity within the ACCESS database.

Data processing:
Plant data are entered first into an EXCEL spreadsheet, and eventually transferred to an ACCESS data base. Outputs from ACCESS are processed with two FORTRAN programs. The FORTRAN programs use algorithms to convert the ACCESS data outputs to plant weight, density, births, deaths and growth (Morris and Haskin, 1990). Fortran outputs are entered into SAS programs to calculate treatment means of biomass, density, and production.

(Morris and Haskin, 1990. Ecology 71(6):2209-2217)
(SAS System for Windows; release 8.02; SAS Institute, Inc; Cary, NC)

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    
DAY day   datetime     dd    
TRT treatment   nominal N=fertlized with nitrogen only | P= fertilized with phosphorus only | NP=fertilized with nitrogen and phosphorus | C=control (not fertilized)        
MEAN BIOMASS biomass dry weight (treatment mean) gramPerMeterSquared ratio   real   . .=not sampled
STANDARD ERROR standard error of dry weight biomass gramPerMeterSquared ratio   real   . .=not sampled