Regional Analysis of Net Ecosystem Productivity of Pacific Northwest Forests: Scaling Methods, Validation and Results Across Major Forest Types and Age Classes

EPA Grant Number: R828309
Title: Regional Analysis of Net Ecosystem Productivity of Pacific Northwest Forests: Scaling Methods, Validation and Results Across Major Forest Types and Age Classes
Investigators: Law, B. E. , Acker, S. , Cohen, W. , Daly, Christopher , Harmon, M. E. , Turner, D. , Unsworth, M.
Institution: Oregon State University
EPA Project Officer: Hahn, Intaek
Project Period: July 1, 2000 through June 30, 2003 (Extended to June 30, 2004)
Project Amount: $1,848,927
RFA: Regional Scale Analysis and Assessment (1999) RFA Text |  Recipients Lists
Research Category: Ecosystems , Ecological Indicators/Assessment/Restoration


(1) To develop and test a regional scale approach that combines modeling, data from remote sensing, sample surveys and intensive research sites to better estimate variation in the carbon balance of forest ecosystems in the Pacific Northwest; (2) To apply our strategy to investigate how processes controlling variation in net ecosystem productivity are influenced by forest development, disturbances and contrasting climatic conditions.


Net ecosystem productivity (NEP) is a critical characteristic of terrestrial ecosystem response to environment. Processes controlling NEP operate on a variety of temporal and spatial scales and are influenced by physiology, allocation, forest development, climate and disturbance. We propose to simulate NPP and NEP in Oregon and Washington using a combination of remote sensing, site data and process models. Model outputs will be tested using detailed ecosystem studies at intensive sites, more basic ecological measurements at other existing intensive sites, and survey data from Forest Health Monitoring (FHM) and Forest Inventory and Analysis (FIA) plots. In spatially explicit applications, we will predict and evaluate forest productivity for an east-west longitudinal swath along a steep climatic gradient through central Oregon from the coast to the semi-arid east side of the Cascade Mountains, and a north-south latitudinal swath from the southern Oregon border to southern Washington. These swaths encompass: (1) six Oregon Transect Ecosystem Research (OTTER) project sites across central OR (Law and Waring 1994a), (2) two tower flux sites in young and old ponderosa pine, (3) two tower flux sites in young and old Douglas-fir/hemlock in WA, (4) long-term vegetation plots at HJ Andrews LTER, (5) Cascade Head Experimental Forest, and (6) FHM and FIA survey data for the PNW region. BIOME-BGC, a physiologically-based process model, will generate current NEP, NPP, and "carbon stress index" surfaces for the regions for a mean climate year, 1999, and 2000. STANDCARB, an ecosystem process model, will be used to estimate current carbon pools by accounting for long-term trends in NEP. We will initialize BIOME-BGC using remote sensing (Thematic Mapper) estimates of forest cover type, age class and LAI and soil survey data (FHM, STATSGO). The model will be driven by spatially distributed climate data based on interpolations of weather station data by the PRISM and DAYMET models. Remotely sensed variables will be validated with data from intensive sites, FHM, FIA and new measurements in under represented forests. Short-term predictions (monthly, annual) of NEP will be validated against tower flux data. Annual predictions of aboveground NPP and its components will be validated with intensive site measurements of stemwood and litter production. Predictions of carbon stores will be validated with FHM and FIA data. We will evaluate sensitivity of NEP to forest type, developmental stage, disturbance, and interannual variability in climate.

Expected Results:

We will demonstrate a practical approach for linking remote sensing, sample surveys, and intensive site data via modeling at the regional scale. This will result in more effective use of multiple data sources and improve the geographic detail in quantifying the response of ecosystems to natural and anthropogenic stresses. This will be a major advance beyond site-based simulations, bridging the gap to global applications. This information can be used by regional planners and program leaders to develop more effective monitoring programs and assessments.

Publications and Presentations:

Publications have been submitted on this project: View all 35 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 22 journal articles for this project

Supplemental Keywords:

regionalization, ecological effects, carbon fluxes, remote sensing, surveys., RFA, Scientific Discipline, Air, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, climate change, State, Forestry, Ecological Effects - Environmental Exposure & Risk, Regional/Scaling, Pacific Northwest, anthropogenic stresses, carbon allocation, ecological effects, semi-arid environments, ecological exposure, ecosystem assessment, Oregon, survey data, forest inventory and analysis, forest ecosystems, climate, natural stressors, Washington (WA), regional scale impacts, ecosystem indicators, forests, remote sensing imagery, ecosystem stress, forest resources, ecological response, validation, OR, carbon stress index

Progress and Final Reports:

  • 2001 Progress Report
  • 2002 Progress Report
  • 2003
  • Final Report