Treesearch

Changes in size of annual and seasonal yields and instantaneous peak flows were determined on three small, experimental watersheds following three silvicultural methods of timber harvest. Changes are related to changes in forest hydrologic system.

Big huckleberry (Vaccinium membranaceum Dougl. ex Hook.) berry production is declining in many northwestern huckleberry fields as they are invaded by subalpine trees. Seeking ways to halt this invasion and increase berry production, the authors studied huckleberries in the Cascade Range of Oregon and Washington from 1972 to 1977. They developed methods of growing huckleberries in the laboratory, tested several methods of controlling competing vegetation in the field, and recorded the changes in plant species composition and huckleberry production that resulted from applying these methods....

Effects of manganese (Mn) on Douglas-fir grown in soil, with and without urea, and in nutrient solution were investigated. In addition, Mn sorption by forest soils was evaluated. Results show that Douglas-fir does not respond to added Mn and is quite tolerant to high Mn levels. Moreover, Mn sorption by soils is high. It is doubtful that Mn toxicity is of practical importance to production of Douglas-fir under forest conditions.

Chemical factors suspected of influencing seasonal change in deer preference for red alder leaves were investigated. There were many differences in the leaves between seasons. It is postulated, however, that changes in contents of crude fat and total phenols were the important factors in increasing deer preference for the species from June to September.

Yield and composition of essential oils were compared in foliage of Douglas-fir. Five clones with different susceptibilities to deer browsing were used; foliage was collected during the dormant season. There were no qualitative differences among the oils of the different clones, but the oils differed quantitatively in all variables measured. Eight variables appeared useful in separating resistant from susceptible clones. Only one compound, however, an unidentified chemical, seemed capable of distinguishing between all three deer browsing preference classes.

Examination of cross-sections of 54 red alder trees from 14 stands of varying age and site conditions indicated that abnormal rings (false, partial, or missing) occur infrequently. Rings may be indistinct and ring counting must be done with great care, preferably on prepared surfaces (cross-sections or cores) and under magnification and good lighting. With such preparations, ages of red alder trees can be determined with acceptable accuracy by conventional ring-counting procedures.

This paper presents height growth and site index curves and equations for even-aged, managed stands of ponderosa pine east of the Cascade Range in Oregon and Washington where height growth has not been suppressed by high density or related factors.

This report presents the findings of a 100-percent canvas of the primary forest products industry in California for 1976. Tabular presentation includes characteristics of the industry log consumption and disposition of mill residues. Accompanying the tables is a descriptive analysis of conditions and trends in the industry.

The 1976 Oregon timber harvest of 8.15 billion board feet ended a 3-year decline. The cut was 783 million board feet (10.6 percent) above the 1975 harvest. The western Oregon harvest rose 812 million board feet (15 percent) while eastern Oregon declined 29 million board feet (15 percent). The proportion of total harvest which comes from eastern Oregon has gradually increased from about 12 percent in the early 1950's to about 24 percent in recent years. After falling below the private cut in 1975, harvest on public lands accounted for 56 percent of the total in 1976.

This report presents statistics on forest area and timber volume and a description of the recent and future timber situations in Alpine, Amador, Calaveras, Fresno, Kern, Kings, Madera, Mariposa, Merced, Mono, San Joaquin, Stanislaus, Tulare, and Tuolumne Counties, California.