Treesearch

Rapidly chancing land use patterns are having a significant impact on watershed management and the included elements of fuel management and fire protection. The complexity of watershed management was defined in the Watershed Management Council's publication prepared for the first conference. This publication, California's Watersheds, emphasized that all land use activity has an impact, that individual impacts can be cumulative and even synergistic. In California, the impact of development on fire effects and fire protection is a grand example.

Fire management has always meant fire suppression to the managers of the chaparral covered southern California National Forests. Today, Forest Service fire management programs must be cost effective, while wilderness fire management objectives are aimed at recreating natural fire regimes. A cost-effectiveness analysis has been developed to compare fire management options for meeting these objectives in California's chaparral wilderness. This paper describes the analytical procedure using examples from a study currently being conducted for the Los Padres National Forest, and discusses some...

Stand patterns of annosus root disease include various degrees and patterns of tree mortality; tree crown, root collar, and root symptoms; and the condition and location of stumps. In the Intermountain states of Montana, Idaho, and Utah, annosus root disease is found in the ponderosa pine, mixed conifer and high-elevation fir forests. Stand patterns are of value in diagnosing the disease in each of these forest types, but other root pathogens may cause similar symptoms. Confirmation of annosus root disease depends upon further steps in the diagnosis process.

Pertinent literature on the biological aspects of annosus root disease is reviewed. Key features of the life cycle of Heterobasidion annosum such as stump infection, stump colonization, host-parasite relations, and interactions of various physical and biological factors are discussed in relation to forest stands in the western United States. This review suggests our knowledge of the pathology of this disease is limited on most affected tree species. Further research on various aspects of the life cycle of this fungus is essential to minimizing losses to this disease.

Recent advances in the genetics and population biology of Heterobasidion annosum are reviewed. H. annosum is a heterothallic (outbreeding) basidiomycete with a unifactorial, multiallelic incompatibility system which regulates mating. H. annosum in western North America consists of two intersterility groups (biological species) which can be identified through mating tests and isozyme analysis. Intersterility groups in western North America appear to be host specific. Intersterility between groups is attributable to specific genes. Intergroup hybrids have been formed in the laboratory, but...

The California Department of Conservation, Division of Mines and Geology provided technical assistance to the California Department of Forestry and Fire Protection in assessing potential geologic hazards that could be affected by proposed prescribed burns on Mt. Tamalpais. This research yielded the following conclusions: (1) landsliding and surface erosion have contributed to the denudation of Mount Tamalpais; (2) Debris flows and surface erosion could affect property and the environment on and below the mountain; (3) The removal of chaparral will reduce the stability of the slopes; and...

Fires were a part of our wildlands prehistorically. Prescribed burning reduces fire hazard and potential fire behavior primarily by reducing fuel quantity and continuity. Fuel continuity should be considered on the micro scale within stands, the mid-scale among, and the macro-scale among watersheds or entire forests. Prescribed fire is only one of the tools which can be used to reduce fire hazard, but it can be effective at all scales.

Prescribed burning for fire hazard reduction in the chaparral is predicated on the belief that young fuels (20 years old and less) are highly resistant to burning. To test this belief, a data base search of large fires in San Diego County between 1940 and 1985 was conducted to locate reburns of young chaparral fuels greater than 1000 acres (400 ha) in extent. Of the 147 fires examined, 17 (11.6 percent) contained at least one area of young fuels that had reburned. The majority of the reburns occurred under severe weather conditions. The finding that young fuels do not necessarily inhibit...

The distribution of Plecoptera along a California river was used to test several predictions of the River Continuum Concept about how functional feeding groups should change along a stream's length. Stoneflies were collected from stream orders 1-6 (123 km) of the Cosumnes River continuum in the central Sierra Nevada. The 69 stonefly species collected were separated into three functional feeding groups – 26 shredders (detritivores), 39 predators (engulfers), and 4 scrapers. Stonefly shredders and predators reached maximum species richness at middle stream orders (3-5). The relative abundance...

The fires of 1987 had a heavy impact on the Hayfork Ranger District. Over 50,000 acres were burned within the South Fork Trinity River watershed, which contains an important anadromous fishery. Major problems within the burned area were found to be: (1) slopes having highly erodible soils where intense wildfire resulted in a total loss of ground cover, and (2) burnout of the natural woody sediment barriers in stream channels. Emergency watershed treatments included aerial seeding of selected slopes with species selected for their ability to germinate quickly and re-establish ground cover....