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Contact Information

Northern Research Station
11 Campus Blvd., Suite 200
Newtown Square, PA 19073
(610) 557-4017
(610) 557-4132 TTY/TDD

Providing Clean Air and Water

Critical Loads Projects

A group from the Center for Research on Ecosystem Change, Northern Research Station RWU-7 led by Linda Pardo is currently working on several projects related to critical loads.

For more information about any of these projects, contact Linda Pardo

Critical Loads Mapping for New England States

The goal of this project is to use published, modeled, and online data to calculate critical loads and develop maps for New England States.

  • NEG/ECP Forest Mapping Research Project
    Generate maps of eastern Canadian Provinces and the six New England states that identify forest areas most sensitive to acidic deposition (N and S).
  • Forest Health Monitoring - Forest Inventory Analysis
    Incorporate FHM-FIA plots into the New England assessment of forest sensitivity to S and N deposition; evaluate current ecological indicators (crown health, growth and mortality) at the plot level.

Please see the Publications & Products section for information on critical loads calculations, parameters, and data management.

Dynamic Modeling

The goal of this project is to estimate Critical Loads using multiple models: the Steady State Mass Balance (SSMB), the Very Simple Dynamic Model (VSD), Model for Acidification of Groundwater in Catchments (MAGIC), and PnET-BCG.

  • Maine
    Estimate Critical Loads for Maine using SSMB and VSD.
  • Assessment of Critical Load of N and S to Great Smoky Mountain National Park
    Calculate critical loads for sulfur (S) and nitrogen (N) deposition to forested ecosystems in Great Smoky Mountain National Park based on existing data using SSMB and VSD.
  • Model Comparison in Northern New England and Adirondacks
    Compare critical loads for Northern New England and Adirondack (NY) sites using SSMB, VSD, MAGIC, and PnET-BCG.

Critical Loads Protocol for Federal Land Managers

The purpose of this project is to develop a set of guidelines and calculation procedures for the determination of critical loads of nitrogen and sulfur for forest ecosystems in Class 1 Areas throughout the United States.

Critical Loads Demonstration Plots

The purpose of this project is to inform air resource specialists of methods available for developing terrestrial critical loads, and to develop a strategy for estimating critical loads in Forest Service Class 1 Areas. The development of demonstration plots will allow evaluation of the plot design, logistical requirements and maintenance concerns prior to developing a broader network of sites in the future

More information on the critical loads demonstration plots.

Last Modified: 08/19/2008