Treesearch

Water is often at the heart of contentious debates over natural resource policy in the Sierra Nevada. Besides the obvious issues of dams, diversions, fish, wetlands, and pollution, connections abound with other resources within the waterways and their watersheds. Whether an argument is over logging, roads, wildfire, endangered species, wilderness, sprawl of foothill communities, ski area expansion, mining, off-highway vehicles, climate change, or overgrazing, potential impacts on water or aquatic habitats quickly enter the discussion. These debates are often dominated by folklore and...

This recommended RNA is on the Lassen National Forest, Tehama County. It is about 9 miles (14 km) SE. of Paynes Creek. It occupies portions of sects. 33 and 34 T28N, R1E, sects. 2, 3, 4, 9, 10, 11, 12, 13, 14, and 15 T27N, R1E MDBM (40°13'N., 121°50'W.), USGS Panther Spring and Dewitt Peak quads. Ecological subsection – Tuscan Flows (M261Fa).

This candidate RNA is on the Klamath National Forest. The area is located largely within the Russian Wilderness and is about 6 miles (9.7 km) W. of Callihan. It occupies portions of sects. 18, 19, 20, 29, 30, and 31 T40N, R9W and sects. 25 and 36 T40N, R10W MDBM (41°17'N., 122°56'W.), USGS Eaton Peak quad. Ecological subsection – Upper Salmon Mountains (M261Ag).

In the Sierra Nevada, studies are being conducted to assess the impacts of both anthropogenic and biogenic hydrocarbon emissions on regional tropospheric ozone and fine aerosol production. Impacts of ozone deposition and management practices on ecosystem health are also being studied. Human-induced changes in regional air quality have consequences for Sierra Nevada ecosystems and human health. To explore these consequences, research has been conducted at a site in the central Sierra Nevada since June 1997. The research site is located in a ponderosa pine plantation which is downwind of the...

Spatial and temporal patterns of water flux, ion flux, and ion concentration were examined in a semiarid, snowmelt-dominated forest on the eastern slope of the Carson Range in Little Valley, Nevada (Johnson and others 2001). Variations in data collected from 1995 to 1999 were used to examine the potential effects of snowpack amount and duration on ion concentrations and fluxes.

The Sierran Global Change Program in Sequoia-Kings Canyon and Yosemite National Parks includes a nearly decade-long integrated study of the interactions between climate, forest processes, and fire. This study is characterized by three recurring themes: (1) the use of systems-level models as a framework for integration and synthesis, (2) an effort to extrapolate an understanding from the local scale of field studies to the much larger extent of the two parks and the southern Sierra Nevada, and (3) an iterative model-data dialogue in which model development and analysis provide a context and...

Livestock grazing plays an integral role in the grass-dominated ecosystems of the Sierra Nevada. Grazing has been asserted to influence such key ecological characteristics as water quality, net primary productivity, nutrient cycling, plant and animal diversity, wildlife habitat availability, and oak regeneration (Belsky and others 1999, Kauffmann and Krueger 1984). Although there are many reports of these effects, an important task is determining which assertion constitutes reliable knowledge. In other words, how well do we know the cause of change? In fact, there is precious little...

A general premise of forest managers is that modern silviculture should be based, in large part, on natural disturbance patterns and species' adaptations to these disturbances. An understanding of forest stand dynamics is therefore a prerequisite to sound forest management. This paper provides a brief overview of forest stand development, stand structures, and disturbance regimes and discusses the implications of applying this information to forest management in the Sierra Nevada. It focuses on three forest types that comprise the bulk of the managed land base: mixed conifer, ponderosa...

Most mountain regions in the western United States are covered by forests, which are for the most part recovering from historical harvesting and have been experiencing active fire suppression over approximately the past 100 years (Tilman and others 2000). Whereas many western landscapes are currently perceived as pristine natural systems, the Rockies, Sierra Nevada, and Cascades were essentially deforested between 1860 and the end of the 20th century, during the era of mining, railroad building, and settlement. Currently, the fraction of old-growth forest remaining in the West is variously...

Fire has been a pervasive influence on the Sierra Nevadan landscape for millennia. Lake sediments containing charcoal and pollen indicate that fires have occurred for at least the past 13,000 years. Brunelle and Anderson (2003) found that charcoal accumulation varied with vegetation and temperature, increasing during warm periods dominated by oaks (Quercus spp.) and sagebrush (Artemisia tridentata) and decreasing during cool periods dominated by subalpine species, such as mountain hemlock (Tsuga mertensiana). They concluded that the lake sediment record was consistent with other long-term...