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:WAT-IP-HistoricalNitrogenBudget.02
Dataset Title:Annual estimates of nitrogen loading to the Ipswich River Watershed, 1931 - 2008.
Investigator 1: 
First Name:Wilfred
Last Name:Wollheim
Address line 1:Morse Hall
Address line 2:UNH
Address line 3:
Zip Code:03824
Associate Investigators:Nat Morse
Keywords:PIE LTER, Ipswich River, disturbance, nutrients, nitrogen, fertilizer, atmospheric deposition, food, waste, sewer, export
Abstract:The nitrogen budget of the Ipswich River watershed was reconstructed to explore trends over time, 1931 to 2008, in gross N inputs, net N inputs, riverine exports.Various sources were used to reconstruct major N budget terms for atmospheric deposition, fertilizer, food imports, sewage N exports, riverine N exports.
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 WAT-IP-HistoricalNitrogenBudget
Beginning Date 1931
End Date 2008
Number of Data Records 78
Other Files to Reference
Availability Status Type 1
Quality Control Information
Maintenance Description On-going study, data continue to be added/updated
Log of Changes: Version 01, 23Mar2012, data and metadata update. Used MarcrosExportEML_HTML (working)pie_excel2007.xlsm 3/23/2012 12:08 PM for QA/QC to EML 2.1.0
Version 02: April 18, 2013, data and metadata updated to comply with importation to Drupal and LTER PASTA. Research location name and description checked updated.Used MarcrosExportEML_HTML (working)pie_excel2007.xlsm 3/14/13 12:02 PM for QA/QC to EML 2.1.0
Geographic Description PIE LTER research site including watersheds and estuary, Essex and Middlesex Counties, MA  
Location Bounding Box    
West Bounding Coordinate -71.22  
East Bounding Coordinate -70.75  
North Bounding Coordinate 42.83  
South Bounding Coordinate 42.5  
OR if single point location    
Taxonomic Protocols
Organisms studied
Methods:Atmospheric deposition estimates use the model of Bowen and Valiela (2001) (N deposition = Year * 0.026 - 39.4) * 100.

Gross imports in food = Population in Ipswich * 4.8 kg/person/year.

Fertilizer inputs are from Ruddy et al. 2004 and Battaglin, scaled to proportion of Ipswich in Middlesex and Essex county MA. Fertilizer estimates for prior to 1945 assumethe decay function derived from Vadeboucour et al. 2010.

Human waste N export is assumed to occur for population on sewer systems (all waste water treatment plants are outside the basin boundaries). Proportion of the population on sewer systems is based on data from Claessens et al. 2006.

Net Food N inputs are Gross imports - Sewered Exports.

Riverine N exports are based on the PIE LTER long term nitrogen database. The USGS Load Estimator program LOADEST was applied to the monthly grab sample data over the perriod of record to predict daily nitrogen flux from 1993 to 2009.

Runoff is derived from th USGS gage at Ipswich period of record from 1934 to present

N in water diversions uses net interbasin transfers of water from Claessens et al. 2006, and assumes concentration as at the mouth of watershed used to claculate riverine N exports.

Bowen, J.L. and Valiela, I. 2001. The ecological effects of urbanization of coastal watersheds:Historical increases in nitrogen loads and eutrophication of Waquoit Bay estuaries. Canadien Journal of Fisheries and Aquatic Sciences. 58, 1489-1500.

Claessens, L., C. Hopkinson, E. Rastetter, and J. Vallino. 2006. Effect of historical changes in land use and climate on the water budget of an urbanizing watershed. Water Resources Research 42:W03426.

Data Table

Variable Name Variable Description Units Measurement Scale Code Information Number Type DateTime Format Missing Value Code Missing Value Code Explanation
Year year   datetime     YYYY NA NA = data are not available
Runoff mean annual runoff millimeterPerYear ratio   real   NA NA = data are not available
AtmosphericDeposition total annual wet and dry deposition kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
GrossFoodN total annual gross food N imports kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
FertilizerN total annual fertilizer N inputs kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
SewerNExport total annual sewer N exports kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
NetNInput net total annual N inputs kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
Nexport total annual riverine TDN exports kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available
NinWaterDiversion total annual TDN exports in water diversions kilogramPerKilometerSquaredPerYear ratio   real   NA NA = data are not available