Biscuit Fire Project Methods

Study Area and Fire History

Southwest Oregon lies within the Klamath-Siskiyou ecoregion, renowned for its botanical diversity, complex geology, and steep climatic and topographic gradients (Whittaker 1960). The area supports a mosaic of coniferous forests, serpentine woodlands, and montane chaparral-type shrubs and hardwoods. Forest types in the study area are the upper portion of the mixed evergreen zone, trending into the white fir zone (Franklin and Dyrness 1973), dominated by conifer species including Douglas-fir (Pseudotsuga menziesii), sugar pine (Pinus lambertiana), white fir (Abies concolor), and knobcone pine (Pinus attenuata). Typical evergreen hardwoods include Pacific madrone (Arbutus menziesii), tanoak (Lithocarpus densiflorus), chinquapin (Chrysolepis chrysophylla), and canyon live-oak (Quercus chrysolepis) and shrubs such as manzanita (Arctostaphylos patula, A. columbiana) and ceanothus (Ceanothus velutinus, C. integerrimus).

Major vegetation types (plant association groups) in the Biscuit Fire area reflect gradients in precipitation and elevation and are often used as a stratification tool for regeneration management (Vagle 1986, Hobbs et al. 1992). These vegetation types include low- to mid-elevation dry sites in the eastern portion of the burn (tanoak/oak and Douglas-fir associations, respectively), low- to mid-elevation wetter sites in the western portion of the burn (tanoak associations), and high-elevation sites distributed throughout the burn (white fir associations) (USDA 2004). Other distinct communities occur on ultramafic (serpentine) soils which cover ~23% (45 000 ha) of the burn area; these communities have a unique ecology (Whittaker 1960, Hobbs et al. 1992) and are outside the scope of this study.

The Klamath-Siskiyou region is characterized by a mixed severity fire regime with long dry summers and high productivity deriving from cool, moist winters. Spatial and temporal variation in fire frequency is high, with mean fire return intervals ranging from 5-75 years (Agee 1993). Recent fire history work in the region from similar forest types suggests that frequent fire was prevalent throughout the region leaving a patchy distribution of stands across the landscape (Taylor and Skinner 2003). South aspects and mid- to upper slope positions experienced the highest fire frequencies while north and east aspects at mid and low slope positions possessed the longest fire return intervals. At coarser spatial scales, fire return intervals lengthen at higher elevations (white fir) and with increasing proximity to the ocean and associated maritime influence (Agee 1993).

In early September 1987, thunderstorms in southwestern Oregon and northwestern California ignited a series of fires that ultimately burned over 140,000 ha. Three of the fires in Oregon were the Silver, Galice, and Longwood Fires (Fig.1). In mid-July 2002, at least two separate lightning strikes ignited fires on the Siskiyou National Forest in Southwestern Oregon which eventually grew together to become the 200,000-ha Biscuit Fire that persisted until early November rains began. One of the Biscuit ignitions occurred within ~1 km of the Silver Fire ignition. Much of the Biscuit Fire burned during a brief period of extreme northerly and easterly winds and low humidity (USDA 2004). The Biscuit Fire completely reburned the 38,000-ha 1987 Silver Fire, while the 8000-ha 1987 Galice Fire and the 4000-ha 1987 Longwood Fire remained outside the Biscuit fire perimeter (Fig.1).

Methods

• Study Design
• Bird Data
• Small Mammal Trapping
• Vegetation and Stand Structure Measurements