WWETAC Projects

Project Title: Evaluating forest and rangeland development in the Western United States

Principal Investigator: Jeffrey D. Kline, USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR


Collaborators: Becky Kerns, USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR; Roger B. Hammer, Department of Sociology, Oregon State University, Corvallis, OR

Key Issues/Problems Addressed:

Forests and range-lands are increasingly subject to disturbances such as wildland fire, insect/disease outbreaks, and urban development. Synergisms among disturbances, and their potential impacts, are difficult to evaluate due to a lack of basic knowledge about the combined effects of these events.

Setting and Approach:

This project evaluated the potential for combined landscape disturbances in Idaho, Montana, Oregon, Washington, and Wyoming. Possible interactions among multiple threats (wildfire, insect/disease, and development) were evaluated using GIS maps characterizing the “neighborhood” surrounding each individual disturbance potential at various spatial scales.

Key Findings:

  • Maps of combined disturbance potential may be more useful than simple overlays of maps showing individual disturbance potentials.
  • Spatial scale matters (e.g., a map that was intended for national-level assessment could be highly misleading when used for fine-scaled analysis).
  • Disturbance combinations of wildfire with insects and disease are predicted for extensive portions of forest and range lands in the northwestern U.S., yet the combination of wildfire with human development (i.e., houses) is predicted to affect a much smaller area.


An absence of accurate data to predict how specific forest/range-land disturbances are likely to interact, both spatially and temporally, poses a significant challenge to planning and policy making. Hypothetical neighborhood analysis of individual disturbance potentials may help anticipate likely disturbance interactions (and related implications) across forest and range landscapes.

WWETAC Project ID:  FY06BK6