PARENT SESSION
Oral Session #54: Fire Ecology -- Trees, forests, woodlands.
Presiding: E. Menges
Wednesday, August 7. 8:00 AM to 11:30 AM. Apache Meeting Room, TCC.
An assessment of historic fire-vegetation relationships in the eastside pine forest of California.
Norman, Steven*,1, Taylor, Alan2, 1 USDA PSW Redwood Sciences Lab, Arcata, CA2 The Pennsylvania State University, University Park, PA
ABSTRACT- In the interior West, historic stand densities and disturbance histories have been reconstructed to describe how vegetation has changed due to a century or more of livestock grazing, logging and fire suppression. We provide reconstructions for the Pinus ponderosa / Pinus jeffreyi forests of Lassen National Forest, California using tree ring-based analyses from multiple half-hectare plots. Stands were reconstructed to the time of the last fire, which varied among plots. During the century before the arrival of Euro-Americans (before 1850), fire regimes and vegetation dynamics varied both spatially and temporally. Changes in fire intervals, fire season and fire extent varied among sites in part from the destabilizing effects of climate. Tree establishment was often episodic and only somewhat consistent with changes in disturbance. These results suggest that reference conditions, as defined by either reconstructed vegetation structure or a selected period with defined fire intervals, may be contingent on both the time period and location considered. In complex landscapes, such landscape-scale heterogeneity may limit the application of the reference condition concept for fire and fuel reduction strategies.
KEY WORDS: restoration ecology, fire ecology, ponderosa pine, california