Treesearch

The RAPID (riparian aerial photographic inventory of disturbance) technique is a method for using measurements made on aerial photographs of patterns of riparian canopy disturbance to evaluate changes in channel conditions through time and to link such changes with their possible upstream causes. The RAPID technique provides resource specialists and managers with a relatively quick way of identifying stream reaches that are chronically or recently disturbed by a variety of channel processes, including increased peak flows and sedimentation from point and nonpoint sources. With examples...

Three market-based methods for estimating values of sport fishing were compared by using a common data base. The three approaches were the travel-cost method, the hedonic travel-cost method, and the household-production method. A theoretical comparison of the resulting values showed that the results were not fully comparable in several ways. The comparison of empirical results showed differences in values not easily accounted for on theoretical grounds. The data base was not designed to provide data for all three methods, and some of the resulting models explain only a small proportion of...

This paper presents an improved version of BDEN, an interactive computer program written in FORTRAN 77 that will calculate soil bulk density and moisture percentage by weight and volume. Calculations allow for deducting coarse fragment weight and volume. The program will also summarize the resulting data by giving the mean, standard deviation, and 95-percent confidence interval for one or more groupings of data.

Gravel pits built during road construction in the early 1970's near Yakutat, Alaska, filled with water and were connected to nearby rivers to allow juvenile salmonids to enter. Seasonal changes in population size, length and weight, and length frequencies of the coho salmon population were evaluated over a 2-year period. Numbers of coho salmon fluctuated, but two of the ponds supported high populations, more than 2,000 fish, throughout the study. These ponds appeared to support coho salmon throughout the winter. The range of physical measurements of the ponds did not seem to account for...

A fully illustrated key is presented for identifying genera of oribatid mites known from or suspected of occurring in the Pacific Northwest. The manual includes an introduction detailing sampling methodology; an illustrated glossary of all terminology used; two color plates of all taxa from the H. J. Andrews Experimental Forest; a diagrammatic key to the 16 major groups of adult oribatids; illustrations to aid in quick recognition of the 16 adult groups; keys to all adult genera; and a diagrammatic key to the major types of immature oribatid mites with local species illustrated. The text...

Four plausible sets of stumpage supply and demand equations were developed and estimated; the demand equation was the same for each set, although the supply equation differed. The supply specifications varied from the model of regional excess demand in which National Forest harvest levels were assumed fixed to a more realistic model in which the harvest on the National Forests depended on current Federal timber sales, uncut-volume-under-contract, and stumpage price. Each set of equations was estimated with annual time-series data for Montana to test the effect of changing supply specificati...

A statewide inventory of shrubs in chaparral and on timberland and woodland in California is presented, and the relevance of shrubs to resource management is discussed. Shrub types (excluding coastal sage and Great Basin and desert shrubs) cover about 10 million acres, 73 percent of which is chaparral. Chamise is the most widespread type in chaparral (51 percent of total area). Critically flammable chaparral stands cover an estimated 1 million acres, much of which is in heavily populated southern California. More than 2 million additional acres are on the threshold of the critically...

The need for and the evaluation of elk-habitat evaluation models are reviewed, and a state-of-the-art example is presented that incorporates distribution of elk-habitat use related to distance from cover/forage edges, distance from roads, cover quality, and forage quantity and quality.

The 2412-hectare Mount Prindle Research Natural Area is located in central Alaska on the border of the Steese National Conservation Area and White Mountains National Recreation Area. It is managed by the U.S. Department of the Interior, Bureau of Land Management, Steese-White Mountains District. Mount Prindle was selected as a Research Natural Area (RNA) because it contains outstanding examples of solifluction lobes; habitat for wheatear (a small thrushlike bird), caribou, and Dall sheep; the yellow-flowered mustard Draba paysonii, which is uncommon in Alaska; a diversity of alpine plant...

Interspecific crosses of Abies religiosa (HBK.) Schlecht. & Cham. (oyamel) with Abies concolor (Gord. & Glend.) Lindle. ex Hildebr. var. concolor (white fir) and Abies magnifica A. Murr. (California red fir) were undertaken to explore the relationships between these species. The cross with A. magnifica produced no germinable seed, but many sound seeds were produced from the cross with A. concolor. These were sown in the nursery in 1968 and outplanted in 1970. In 1983, morphological characteristics of seven putative hybrids were compated with those of teh A. concolor seed parent, herbarium...