Treesearch

The dry-weight-rank method of estimating botanical composition on California's annual grasslands is a viable alternative to harvesting and sorting or methods using points. Two data sets of sorted species weights were available. One spanned nine years with quadrats harvested at peak of production. The second spanned one growing season with 20 harvest dates. Two existing sets of coefficients for the first, second, and third ranked species and one calculated from our data were used to estimate dry-weight composition. We tested the differences between the estimates and actual values. Difference...

In forestry the importance of genetic variation for successful reproduction, survival and growth has been widely documented for commercial conifers; until recently, little genetic work has been done on the California oaks. Even before the nature of genetic variation was scientifically investigated, its importance was suspected in operational forestry. Many failures of commercial plantations were traced to the use of seedlings that, although of native species, were derived from populations distant from the planting site. Similarly, in areas that were regenerated with planted seedlings...

The symposium from which the papers in this issue derive was organized to foster an awareness among forest managers of the issues surrounding biological diversity. Forest geneticists have been calling for conservation of diversity for many years (Anonymous, 1975). Since they were geneticists, they naturally called this gene conservation. Forest geneticists often sold gene conservation from a practical viewpoint. Genes were needed in breeding, as raw material for selection, and to maintain viable populations of commercial species. That argument is as valid as ever, but over time we have...

We report on an intensive research effort to determine the present status of the marbled murrelet (Brachyramphus marmoratus) in the vicinity of Redwood National Park, in Del Norte and northern Humboldt Counties, California. This seabird is primarily an inhabitant of the nearshore waters and adjacent coastal redwood forests of the northern half of the state. Little is known of its ecology on land. Using remote sensing techniques, we mapped all old and mature forests, the potential habitat for the species. We then conducted systematic surveys of stands selected from the above inventory,...

Considerable public criticism and sometimes legal obstructions have been directed toward landscape management in relation to the extraction of natural resources. Many managers do not understand public concerns for visually attractive resources. Managers need to know when landscape alterations, like clearcuts, attract public attention and become visually objectionable. A study assessed the opinions of groups of people, representing various organizations, using color slides to simulate views of managed and natural landscapes. Of 63 management actions, 43 were not detected by more than half...

The use of mulches as a reforestation tool in Oregon and California began primarily in the late 1950's. Many types of mulches were tried including sheets of plastic, newspaper, and plywood; various thicknesses of bark, sawdust, sand, and straw; sprayed-on petroleum resin; and even large plastic buckets. Most proved to be ineffective, costly or both. Early trials tended to use small, short-lived materials that aided conifer seedling survival, but not growth. Compared to other weed-control techniques available at the time, mulches were rather expensive. Current trends are to apply longer-live...

This report summarizes each of 68 ecological surveys conducted from 1975 through 1988 on candidate and established Research Natural Areas in the Pacific Southwest Region of the USDA Forest Service. These surveys represent an important but largely unknown contribution to the ecological literature of California. For each summary, information on location, target elements, distinctive features, physical characteristics, association types, plant diversity, and conflicting impacts is provided. Comparisons are made between similar vegetation types at different sites. Tables and appendices...

The perception of mangroves by people in the Pacific islands and throughout all the world has changed in the past decades. Today, the economic, social, ecologic, and esthetic values of mangroves are well recognized. Past research on these ecosystems is responsible for the change in perception. However, a review of eleven subjects relevant to the management of Pacific mangrove forests revealed numerous gaps in quantitative understanding of man-grove functions and values. These gaps must be filled if the gains in public perceptions of mangrove values are to be institutionalized through...

A population of 638 timber harvest areas in northwestern California was sampled for data related to the occurrence of critical amounts of erosion (>153 m3 within 0.81 ha). Separate analyses were done for forest roads and logged areas. Linear discriminant functions were computed in each analysis to contrast site conditions at critical plots with randomly selected controls. Bootstrapping was used extensively in the development and testing of the equations, in estimating prediction bias, and in placing confidence limits around parameters and posterior probabilities. The resulting three-variabl...

Caspar Creek experimental watersheds are located on the Jackson Demonstration State Forest. Sponsors are the Pacific Southwest Research Station (PSW), USDA Forest Service, and the California Department of Forestry and Fire Protection (CDF). Both organizations have been working cooperatively since 1962