Treesearch

Intragravel water exchange provides oxygenated water, removes metabolic waste, and is an essential factor in salmonid embryo survival. Measurements of intragravel flow velocity have been suggested as an index of gravel quality and also as a useful predictor of fry emergence; however, proposed methods for measuring velocity in gravel are problematic. We evaluate an ion adsorption technique that uses natural streamwater solute chemistry, which therefore does not require introduction of a dye or solute tracer. However, the method requires an access tube for placing an ion exchange resin bag...

A study of visitors to Oregon's Eagle Cap Wilderness in 1965 offered a baseline against which to evaluate how those who recreate in wilderness have changed their views of wilderness. A study of visitors to that same wilderness area in 1993 provided comparative data. Some characteristics of the visitors changed in ways that would suggest that the values visitors placed on wilderness and on the behaviors they would consider appropriate had changed as well. Specifically, visitors were better educated and were more likely to be members of conservation or outdoor recreation organizations. In...

Prescribed burning is an effective way of restoring the fire process to ponderosa pine (Pinus ponderosa Doug I. ex Laws.) ecosystems of the Southwest. If used judiciously, fire can provide valuable effects for hazard reduction, natural regeneration, thinning, vegetation revitalization, and in general, better forest health. Relatively short burning intervals are required to maintain the benefits of fire.

Recent underestimates of total volume for timber sales in the Black Hills National Forest prompted analysis of two felled ponderosa pine (Pinus ponderosa Laws.) data sets that were collected approximately 10 years apart. Though neither data set collected was a representative sample of the Black Hills, both were similar in terms of diameter at breast height and total height. We investigated several methods for assessing differences in tree form and applied them to these two data sets. Under the assumption that these two data sets were representative of harvested trees in the Black Hills...

This review of the disturbance ecology literature, and how it pertains to forest management, is a resource for forest managers and researchers interested in disturbance theory, specific disturbance agents, their interactions, and appropriate methods of inquiry for specific geographic regions. Implications for the future of disturbance ecology-based management are discussed.

A major objective of the Forest Service Research Natural Area (RNA) program is to maintain a representative array of all significant natural ecosystems as baseline areas for research and monitoring (Forest Service Manual 4063, USDA Forest Service 1991). The National Forest Management Act of 1976 directs the agency to establish research natural areas typifying important forest, shrubland, grassland, alpine, and aquatic ecosystems. In addition to their value as reference areas for research and monitoring, RNAs help maintain biological diversity and healthy ecosystems on national forests by...

A new satellite-derived vegetation greenness map, departure from average, is designed to compare current-year vegetation greenness with average greenness for the same time of year. Live-fuel condition as portrayed on this map, and the calculated 1,000-hour fuel moistures, are compared to fire occurrence and area burned in Montana and Idaho during the 1993 and 1994 fire seasons.

Forest fire research lost one of its true pioneers on April 12, 1996, when George M. Byram passed away in Dunedin, Florida, at the age of 87. He made lasting contributions in nearly every subject matter area of forest fire research. He was also a gifted painter and a fine gentleman in the eyes of those who knew him.

In 1977, the La Mesa Fire burned across 15,444 acres of ponderosa pine forests on the adjoining lands of Bandelier National Monument, the Santa Fe National Forest, and Los Alamos National Laboratory. Following this event, several fire effects studies were initiated. The 16 papers herein document longer-term knowledge gained about the ecological effects of the fire and about Southwestern fire ecology in general. The presentations are also designed to give resource managers practical information for managing fire in local landscapes. Studies presented range from fire histories and avifauna...

Bird records for the Cimarron National Grassland were collected from literature searches and unpublished field notes submitted by cooperators. Almost 14,000 bird records were compiled in a data file. Based on these data, the status of each bird species reported to have occurred on the Cimarron National Grassland was established. In addition to the species accounts, the history lot the area, current management practices, habitat types, and locations for finding birds are discussed.