USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Forest Reference Conditions

Researchers will reconstruct presettlement (circa 1880) forest reference conditions by studying live and dead trees within a 2000 ha unlogged forest in the General Creek watershed. Based on the age distribution of these trees, they will analyze presettlement fire regimes in relation to topography. They will use the Forest Vegetation Simulator to characterize and depict presettlement forest conditions in different groups, and then they will use the Fuel Characteristic Classification System (FCCS) to characterize surface and canopy fuels in each group and across the landscape using a Geographic Information System (GIS). By modeling fire behavior, researchers will calculate how far current conditions have departed from their presettlement reference conditions.

Full Title: Identifying Spatially Explicit Reference Conditions for Forest Landscapes in the Lake Tahoe Basin, USA

Proposal [pdf]

Lead Researchers: Alan Taylor, Penn State University; Carl Skinner, USFS Pacific Southwest Research Station; Hugh Safford, USFS Region 5


  1. Identify the relationships among spatial variability in presettlement forest structure (composition, density, basal area, size structure), topographic variables, and spatial variability in fire regimes (fire return interval, season of burn) in the lower and upper montane forest zones of the Lake Tahoe basin.
  2. Develop a spatially explicit reconstruction of the presettlement forest landscape conditions and associated fire regimes for the Lake Tahoe basin that can be used by land managers in restoring forest ecosystems.

Forest Conditions


Plot and stand-level data on site characteristics and presettlement forest structure will be obtained for previous studies led by the principal investigator. Further sampling of uncut forest in the General Creek watershed will be necessary to ensure a full representation of forest conditions and topographic variables.

Timeframe: September 2008 through August 2011 (3 years)

Expected date of final products: August 2011. Progress Report available for download


  1. Digital GIS data and maps of the presettlement forest landscape.
  2. Presettlement forest compositional group summaries, including digital data on stand density, basal area, and tree diameter distributions.
  3. Presentations to managers at interagency meetings.
  4. Interagency workshop with managers on how they can use the landscape reconstruction for planning and project implementation.
  5. Two annual reports and a final report.
  6. Publication of results in peer-reviewed journals.
Last Modified: Mar 28, 2013 02:52:07 PM