Treesearch

The success of feeding and development of western spruce budworm (Choristoneura occidentalis Freeman) on callus tissue of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was determined. Fewer insects died when fed pure callus tissue than when fed on standard diet or callus incorporated into the standard diet. The final weight of insects fed callus was less, however, than that of insects fed the standard diet. This demonstrates that either pure callus or callus incorporated in a standard artificial diet can be used to rear budworm. This technique has potential as a bioassay system to...

In this paper we examine the influence of precipitation and temperature deviations on regional volume growth rates in even aged, onnen.,ed second growth Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) stands. Between 1969 and 1986, average volume growth rates in natural stands of coast Douglas fix in western Washington and Oregon were negatively correlated with high summer temperatures and positively correlated with higher temperatures during the non growing season. Results support the hypothesis that cool wet summers and mild winters contribute to high productivity of conifers in the...

In July 1987, a 2-week synoptic survey was conducted on the wetlands of the Copper River Delta by an interdisciplinary team of scientists. Disciplines included geomorphology, limnology—water chemistry and nutrients, plankton and macroinvertebrates, anadromous fish populations, and wetland plant ecology. The purpose of this report is to present a summary of the findings of each group, preliminary conclusions, and recommendations for further research. The results are limited in scope due to the limited observation time and the single point in the year—midsummer. Because all observations were...

Effect of stratification period (S) and incubation temperature (T) on germination be- havior were tested by using two groups of Douglas-fir orchard seedlots that had given low germination percentages in standard tests. One group of seedlots that had experienced different cone-drying regimes, but otherwise were treated comparably, were germinated at T = 15 and 25 °C after S of 21, 42, and 84 days. Cone-drying conditions affected germination behavior. Particularly, low-humidity, high-temperature drying decreased the rate and percentage of germination, but if seeds were given 84-day S, then...

Arboreal rodents in Douglas-fir forests west of the Cascade crest in Oregon and Washington include (listed in decreasing order of dependence on trees) red tree vole (Phenacomys longicaucfus), northern flying squirrel (Glaucomys sabrinus), Douglas' squirrel (Tamiasciurus douglasii), dusky-footed woodrat (Neotoma fuscipes), bushy-tailed woodrat (Neotoma cinerea), and Townsend's chipmunk (Tamias townsendi). The arboreal rodents constitute an ecological community group of species that interact and influence one another’s pattern of abundance and use of resources. All but the Douglas' squirrel...

Fertilizer placed in the planting hole increased height growth of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) early in the life of the plantation. Later broadcast applications of fertilizer may have had little effect on growth. Wider spacings produced larger trees but less volume per acre than narrower spacings after average tree height exceeded 7 feet. Fertilization produced larger trees and more volume per acre at each spacing.

The Timber Resource Inventory Model (TRIM) was used to make several projections of forest industry timber supply for the Douglas-fir region. The sensitivity of these projections to assumptions about management and yields is discussed. A base run is compared to runs in which yields were altered, stocking adjustment was eliminated, harvest assumptions were changed, and management intensity assumptions were changed. The objective was to determine if there is a difference in supply projections and age-class distributions in the short term (20 years) and the long term (50 years) when assumptions...

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Before a bird population is measured, the objectives of the study should be clearly defined. Important factors to be considered in designing a study are study site selection, plot size or transect length, distance between sampling points, duration of counts, and frequency and timing of sampling. Qualified field personnel are especially important. Assumptions applying to all bird-counting techniques are discussed. The following techniques and their applications are discussed; simple line transect, fixed-width transect, variable-width transect, simple point count, fixed-radius point count,...