Study Area

We selected a 3000-km² area located in the Klamath Mountains of northwestern California centered on the town of Hayfork. The majority of the landscape is under Federal management and includes portions of the Shasta-Trinity and Six Rivers National Forests. Private inholdings are common and contribute to wildland-urban interface management problems that are characteristic of the West. These include issues related to wildland fire, air quality, and biodiversity management. Both national forests fall under the Northwest Forest Plan, a 1994 regional plan designed to maintain sustainable forest products and to sustain species. As part of that plan, areas were allocated for different purposes. The primary land allocations present in the study area include Late Successional Reserves that were set aside for old-growth species, including the northern spotted owl, and the Hayfork Adaptive Management Area set aside for experimentation and learning.

The vegetation of the study area consists of a diverse array of conifers, hardwoods, shrublands, and grassy meadows. Douglas fir (Pseudotsuga menziesii) forests dominate a large portion of the area, but forests of ponderosa pine (Pinus ponderosa) occur on dry sites, and Jeffrey pine (Pinus jeffreyi) and incense cedar (Calocedrus decurrens) dominate forests on ultramafic soils. Mixed conifer forests are found where pine, Douglas fir, white fir (Abies concolor), and incense cedar co-occur and typically include various species of hardwoods in the canopy or understory. The most common hardwoods include tanoak (Lithocarpus densiflorus), canyon live oak (Quercus chrysolepis), black oak (Quercus kelloggii) and chinquapin (Chrysolepis chrysophylla). Surface and live fuel composition and structure have been altered from their historical condition by 20^th century fire suppression and logging. Wildfires occur on a regular basis, but extensive, long-burning wildfires have only occurred in 1987 and 1999.