Treesearch

Nine channel types within a hierarchical channel-type classification system (CTCS) were surveyed to determine relations between salmonid densities and species distribution, and channel type. Two other habitat classification systems and the amount of large woody debris also were compared to species distribution and salmonid densities, and to stream channel types. Although trends appeared in salmonid densities and channel types, population estimates were too variable to show a relation between density and channel types. Depth-velocity criteria that separated habitat into shallow-slow,...

Four hundred and eighty-six provisional tree seed zones were delineated within 24 physiographic and climatic regions of Alaska and western Yukon Territory Estimated forest and potential forest land within altitudinal limits of tree species in Alaska was 51,853,000 hectares (128,130,000 acres) Seed transfer guidelines and standard labeling of seed collections are recommended to reduce losses from maladaptation and maintain the genetic identity and productivity of future forests in Alaska.

Dead western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex. D. Don) trees were examined 38 years after intentional girdling (cuts made into wood around the bole) at Cat Island, Alaska, to describe their condition as wildlife habitat. All but 1 of 42 hemlock had boles broken at or below 30 feet. The wood of all standing boles and boles on the forest floor was thoroughly degraded by brown rot fungi, white rot fungi, or both. Western redcedar snags were either standing with primary limbs intact, or were down with boles broken at the girdle. Snags of...

Ethephon (Ethrel), an ethylene-releasing plant-growth regulator, was applied with a hydraulic sprayer to ponderosa pine (Pinus ponderosa Dougl. ex Laws.) infected with dwarf mistletoe (Arceuthobium campylopodum Engelm. f. tsugense (Rosend.) Gill) in the Emmett Ranger District, Boise National Forest. Abscission rates of 60 to 100 percent of dwarf mistletoe shoots were consistently achieved with applications in both July and August of 2,400 p/m of ethephon plus surfactant. Ethephon did not kill the endophytic system of the parasite in the host tissue; new shoots began developing on some of...

A single application of 200 pounds nitrogen (N) plus 33 pounds of sulphur (S) per acre to white fir (Abies concolor (Gord. & Glen.) Lindl.) increased periodic annual increments of basal area and volume by 1.7 ft2acre-1year-1 and 43 to 68 ft3acre-1-year-1 respectively over 4- or 5-year periods. The stands become infested with budworms (Choristoneura occidental is Freeman and C. retiniana (Walsingham)) after fertilization thereby causing increased variability in height growth. The influence of fertilization on height growth therefore was statistically significant in only one of the two...

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...