Wildlife habitats of the north coast of California: new techniques for extensive forest inventory.

Abstract

A study was undertaken to develop methods for extensive inventory and analysis of wildlife habitats. The objective was to provide information about amounts and conditions of wildlife habitats from extensive, sample based inventories so that wildlife can be better considered in forest planning and policy decisions at the regional scale. The new analytical approach involves identifying habitats present on field plots, estimating area present in each habitat condition, and linking the habitat classifications with wildlife-habitat relationship models to describe habitat suitability for wildlife species. The habitat classification system and wildlife-habitat relationship models of the California Wildlife Habitat Relationship Program are used in a case study of the north coast region of California. Tree vegetation types occupy 93 percent of all forest land, and shrub habitats occupy 5 percent. Redwood and Douglas-fir are the most abundant tree habitats; chamise-redshank chaparral is the predominant shrub habitat. Outside parks and National Forests, midsuccessional stages dominate the forest landscape in occupying two-thirds of the timberland area. Two-thirds of forest stands have moderate or dense canopy closure. The suitability of available habitats for reproduction and feeding for eight wildlife species are presented. The estimates of habitat area indicate the availability and patterns of occurrence of these vegetation conditions at a broad scale and should be useful in evaluating potential impacts of proposed actions affecting broad-scale alterations of habitat. The estimates of habitat suitability are used appropriately in regional-level predictions of species occurrence and habitat suitability. Extensive inventory data on special habitat elements such as snags, nontree vegetation, and spatial features of habitat also can be used in resource assessments and ecological research; for example, only 9 percent of the habitat area rated as being of high or medium suitability for reproduction for pileated woodpeckers supports snag habitat required by the species. Large snags are most abundant in dense, pole-sized and larger stands in the redwood type and in large-treed stands of all densities in the Douglas-fir type. Data from continuing forest inventories also are useful for regional-level monitoring of wildlife habitats and in habitat simulations.

Citation

Ohmann, Janet L. 1992. Wildlife habitats of the north coast of California: new techniques for extensive forest inventory. Res. Pap. PNW-RP-440. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 48 p