Treesearch

Dwarf mistletoe causes obvious brooms in Douglas-fir. The brooms are the easiest means of recognizing the presence of dwarf mistletoe; however, dwarf mistletoe is not the only cause of brooming in Douglas-fir. Therefore, accurate identification of dwarf mistletoe brooms is important. If no evidence of aerial shoots can be found in the brooms, and if the brooms occur infrequently, are all relatively small, or are found only in trees where a stand has been opened, then dwarf mistletoe is probably not the cause of brooming. Dwarf mistletoe brooms generally have aerial shoots present and are...

Phellinus weirii cultures were stored successfully for 10 years in small alder (Alnus rubra Bong.) disks at 2 °C. The six isolates tested appeared morphologically identical and after 10 years varied little in growth rate from those stored on malt agar slants. Long-term storage on alder disks reduces the time required for maintaining cultures and the risk of contamination inherent in frequent transfers necessary in storage on agar slants.

A field test showed that degree-days accumulated by a miniature computer and a recording thermograph in early spring and summer were comparable. For phenological studies the biophenometer was as accurate and more efficient than the hygrothermograph.

A hand-held vacuum modified for collecting insects and spiders in the field is described. The vacuum with battery is mounted on a lightweight pack-frame and is portable and versatile. It is especially useful for collecting arthropods that are dislodged from foliage samples and drop onto cloths.

Effects of nitrogen, sulfur, and phosphorus fertilizers on growth and nutrient content of Douglas-fir seedlings potted in Grove and Bunker forest soils were determined. Growth was primarily stimulated with nitrogen in the Grove soil and with phosphorus in the Bunker soil. Fertilization influenced nutrient levels in the seedlings. Growth results agree with observed response of Douglas-fir to fertilization in the field where the soils were collected. Data also suggest that low phosphorus and/or high nitrogen may be responsible for lack of positive growth response of Douglas-fir to nitrogen...

The study reviews Hohenadl's procedure for defining form quotients and tree volume from diameters measured at fixed proportions of total tree height. Modifications of Hohenadl's procedure were applied to two sets of data for western hemlock (Tsuga heterophylla (Raf.) Sarg.) from the Pacific Northwest. The procedure was used to define volume differences in thinned stands, and selected form quotients were used as variables to improve accuracy and precision of standard tree volume equations. Estimating form quotients on standing trees requires less time than complete stem dendrometry. The...

The purpose of this study was to develop and validate estimators to predict total crown weight and weight of any segment of crown for old-growth felled and bucked Douglas-fir and western hemlock trees. Equations were developed for predicting weight of continuous live crown, total live crown, dead crown, any segment of live crown, and individual branches for old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees. A branch method and a ratio method were developed for estimating the weight of crown segments. Equations were...

Data from 1973 and 1980 logging residues studies were used to compare the volume of residue from lump sum and log scale timber sales. Covariance analysis was used to adjust the mean volume for each data set for potential variation resulting from differences in stand conditions. Mean residue volumes from the two sale types were significantly different at the 5-percent level for the 1973 data but were not significantly different for the 1980 data. These inconclusive findings suggest that the relative efficiency of changing sales procedures should be considered before further study is undertaken.

Aerial photo sampling coupled with information taken on the ground provided data for development of estimates of land and forest area by ownership group within the boundaries of the 1971-75 Tanana River Basin timber inventory unit, Alaska. Area of privately owned timberland is estimated at 280,634 acres (113 569 hectares).

Lumber recovery information from 942 logs from old- and young-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws.) trees in northern California is presented. More than 58 percent of the lumber volume was found in 5/4 Shop, Moulding, and Select grades. About 25 percent of the total lumber volume was Moulding, and 24 percent was Standard and Better Dimension. Lumber volume recovery is presented on the basis of cubic feet and board feet. Volume recovery varied by scaling diameter but not by log grade. Value recovery and percent volume by lumber grade did vary by log grade and diameter, but...