Treesearch

Electrophoretic studies of protein polymorphisms in plants have focused upon herbaceous species, primarily inbreeding annuals, in efforts to characterize the levels and patterns of genic variation within and between populations (Clegg and Allard, 1972; Gottlieb, 1973, 1975; Levin, 1975, 1978; Levy and Levin, 1975; Schaal, 1975; Roose and Gottlieb, 1976; Brown et al., 1978; and others). These studies have indicated that predominantly outbreeding species maintain higher levels of intrapopulation variation than predominantly inbreeding species, while inbreeders exhibit a greater degree of...

Abstract - Processes of erosion and sedimentation in steep chaparral drainage basins of southern California are described. The word ""hyperschedastic"" is coined to describe the sedimentation regime which is highly variable because of the interaction of marginally stable drainage basins, great variability in storm inputs, and the random occurrence of brush fires. The difficulties and advantages of describing chaparral sedimentation using either empiric or process models are dicussed. Modeling based on Monte Carlo simulation is suggested as a way of capturing many of the benefits of empiric...

After the flood of December 1964, 12 gaging sections in northern California widened as much as 100% and aggraded as much as 4 m, and then degraded to stable levels during a period of 5 years or more. As channels aggraded, bed material became finer, and low to moderate flow through gaging sections in pools became shallower, faster, and steeper. Comparisons of longitudinal profiles also show the diminishment of pools as well as a decrease in bar relief accompanying the excessive sediment load. As gaging sections degraded, hydraulic geometries recovered to a limited degree; full recovery...

Abstract - Accelerated erosion in the form of landslides can be an undesirable consequence of clearcut logging on steep slopes. Forest managers need a method of predicting the risk of such erosion. Data collected after logging in a granitic area of northwestern California were used to develop a predictive equation. A linear discriminant function was developed that correctly classified almost 90% of the data. The equation was based on measurements of slope, crown cover, tributary drainage area, and distance from a stream. A procedure was then developed by which the discriminant function can...

The California Wildlife/Fish Habitat Relationships (WFHR) System is an ongoing effort to apply our knowledge of wildlife habitat requirements to identify and explain the consequences of proposed land use activities, particularly those activities that affect vegetation. The U.S. Forest Service initiated the WFHR program in California in 1976 and has developed it for all Forest Service lands in the state. The California Department of Fish and Game is currently expanding the WFHR program to include non-Forest Service lands in California.

In analyzing fire management programs for their economic efficiency, it is necessary to assign monetary values to the changes in resource outputs caused by, fire. The derivation of resource values is complicated by imperfect or nonexistent commercial market structures. The valuation concept recommended for fire program analyses is willingness-to-pay because it permits uniform derivation of resource values across all resource categories, and it represents the full economic value of the output to society. The process of measuring fire effects in program evaluations introduces implications...