Treesearch

The nine white pine species native to North America have very different ecological roles and values, which include high quality timber production, important watershed protection, keystone ecological species, and the oldest and some of the most picturesque trees on earth. All are highly susceptible to white pine blister rust (Cronartium ribicola), and some have been damaged severely in parts of their natural range. The epidemic has not yet stabilized, even after a century since introduction of the disease.

To increase the growth of planted conifer saplings, the competing vegetation in a 16-year-old pine plantation on the Plumas National Forest in northern California was mechanically treated with the Tracmac mechanical cutter. The large size of this vegetation (chinkapin, greenleaf manzanita, whitethorn, huckleberry oak) eliminated other release methods as feasible alternatives. Additional treatments were a chemical treatment, in which 2,4-0 was applied to a portion of the study site that had been treated with the Tracmac 2 years previously, and untreated control. Eleven growing seasons after...

In 1993 a cooperative study was initiated by the USDI Bureau of Land Management and the USDA Forest Service’s Pacific Southwest Research Station to study the recreational needs of visitors to the Redding Resource Area in central and northern California. The study addressed specific issues in the Redding Resource Management Plan, such as attracting recreationists from local versus regional populations, as well as items previously established as important in other visitor research pilots, such as preferred amenities. Four seasons of data collection occurred, with the report covering all...

We tested six behavioral chemicals, pityol, conophthorin, 4-allylanisole, verbenone, 2-hexenol, and á-pinene, in a series of field trials directed at six combinations of Conophthorus Hopkins - Pinus L. spp. (Pinaceae) in sites distributed across North America. Beetle - host tree combinations included Conophthorus ponderosae Hopkins on Pinus ponderosa Laws., C. ponderosae on Pinus monticola Dougl., Conophthorus conicolens Wood on Pinus pseudostrobus Lindl., Conophthorus teocotum Wood on Pinus teocote Schl. & Cham., Conophthorus coniperda (Schwarz) on Pinus strobus L., and Conophthorus...

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,...

Biotic properties of forest soil are the linkages connecting forest vegetation with an inert rooting medium to create a dynamic, functioning ecosystem. But despite the significance of these properties, managers have little awareness of the biotic world beneath their feet. Much of our working knowledge of soil biology seems anchored in myth and misunderstanding. To correct this, a conference sponsored by the California Forest Soils Council was held February 23-24, 1996, in Sacramento, California. These peer-reviewed papers of practical significance to forest managers comprise the updated...

As frontiers closed in North America’swildlands during the late 20th Century,ecosystem management emerged as theguiding principle for many public landmanagingagencies. Mandates shiftedfrom emphasis on resource extraction(timber, water, minerals) to ecosystemprotection, and the concept of ecologicalsustainability became central. Themission statements of the U.S. ForestService, Bureau of Land Management,U.S. Fish and Wildlife Serivce, and U.S.National Park Service, for example,herald ecosystem sustainability – maintainingcomposition, structure, and processof a system – as key policy goals.Sim...

Sedimentation of Rio La Venta as it enters the Netzahualcoyotl Reservoir in Chiapas, Mexico, threatens a unique part of the aquatic ecosystem. Rio La Venta enters the reservoir via a narrow canyon about 16 km long with spectacular, near-vertical limestone bluffs up to 320 m high and inhabited by the flora and fauna of a pristine tropical forest.