Treesearch

In this paper we summarize the results of four studies in which we either examined the feeding habits of the northern flying squirrel (Glaucomys sabrinus), a mycophagous (consuming fungi) small mammal, or compared the abundance of truffles (sporocarps of hypogeous mycorrhizal fungi) among different types of fir (Abies) forest. The studies were conducted within the Lassen National Forest in northeastern California between 1990 and 1994. In the first study, we found that abundance of northern flying squirrels was significantly less in old-growth fir stands that had been shelterwood-logged 6...

Large landslides and debris flows in January 1997 produced contrasting downstream debris flood effects in two adjacent Northern California Klamath Mountain streams. Valley morphology and riparian forests were examined on post-flood 1:3000 air photos along two approximately 8 km survey reaches.

This watershed assessment of the Lake Tahoe basin in northern California and Nevada is the first attempt to collate, synthesize, and interpret available scientific information with a comprehensive view toward management and policy outcomes. The seven-chapter report presents new and existing information in subject areas pertinent to policy development and land and resource management in the basin, including environmental history, air quality,watershed dynamics and water quality, biological integrity, and socioeconomic conditions. Key findings report the extent of recent climatic changes,...

Although the spotted owl (Strix occidentalis) has been intensively studied, factors influencing its reproduction are not well understood. We examined a 9-year demographic study of 51-86 pairs of the California spotted owl (S. o. occidentalis), weather conditions, and forest structure at nest sites in oak (Quercus sp.) woodland and conifer forests to assess if weather or nest-site variables are associated with reproduction. Mean reproduction was highly variable between years, but within a given year was largely synchronous among all owl pairs across forest types (i.e., oak woodlands and...

We examined the distribution and abundance of nonvascular epiphytes on western hemlock trees in an oldgrowth coniferous forest focusing on patterns of epiphyte distribution at different spatial scales, epiphyte abundance amongst trees differing in size, and crown structures associated with epiphyte abundance. Total epiphyte cover was greatest in four canopy microhabitats: the upper canopy strata, crowns of large trees, lower crown branches, and inner branch plots. Epiphyte functional groups were stratified vertically within the stand and horizontally within branches. Alectorioid and...

In August 1996 the Jackson Demonstration State Forest (JSDF) completed a fish habitat rehabilitation project in a 2.5 mile reach of Parlin Creek, a tributary to the Noyo River in Mendocino County, California. The purse of the project was to introduce large woody material to the stream channel to determine if higher quality habitat could be produced for anadromous salmonids. The project goals were to: 1) increase depth and complexity of pools, 2) create new pools, and 3) break up long riffles and reduce winter flow velocity.

Thirty openings, 9, 18, and 27 meters in diameter, were created by group-selection harvest on a high quality site in northern California in 1963. In 1991, or 28 years after site preparation, the plant community in the openings had stabilized at 55 species. A major shift was from annuals to perennials. New seedlings of ponderosa and sugar pine were able to become established for the first 15 years and those of Douglas-fir and California white fir for the first 25 years. Density and development of conifer and hardwood saplings, shrubs, forbs, graminoids, and ferns were examined for difference...