Treesearch

Bioassays using deer mice showed that R-55 a thiocarbamate derivative applied as 2-and 5-percent coatings was ineffective in reducing consumption of Douglas-fir seed. At 2 percent3 mestranol3 an antifertility chemical3 reduced seed consumption to levels comparable with endrin applied at 0.5 percent without impairing germination.

This paper presents selected interior Alaska forest and range wildfire statistics for the period 1966-69. Comparisons are made with the decade 1956-65 and the 30-year period 1940-69, which are essentially the total recorded statistical history on wildfires available for Alaska.

Bark from Douglas-fir logs floated in sea water contained 0.75 to 1.94 percent salt (NaCl). Leaching by natural and simulated rainfall and by soaking readily removed this salt. Bush bean and tomato plants were grown in the greenhouse on a sandy loam soil to which bark of three different proportions of salt was applied as a mulch and as an incorporation at the rate of 40 tons per acre. Mulches containing 0.75 and 1.41 percent salt had little effect on beans but bark containing 1.94 percent salt was slightly depressive; all the incorporations were depressive. Tomato plant yields were reduced...

Twenty-one ecosystems of the Silver Lake mule deer range in northern Lake County, Oregon, are described by site, vegetation, and soil. Discussions are included on ecosystem interrelationships, habitat value for game, and habitat manipulation. A field key to ecosystems has been developed using vegetation characteristics easily identifiable on the ground.

This paper is intended for those who wish to prepare an algorithm to determine the load path of a running skyline. The mathematics of a simplified approach to this running skyline design problem are presented. The approach employs assumptions which reduce the complexity of the problem to the point where it can be solved on desk-top computers of limited capacities. The results of this approach are compared with the exact catenary solution.

A comparison of streamflow records from three small mountain streams in north-central Washington before, during, and after a severe forest fire showed three immediate effects of destructive burning. These were: 1. Flow rate was greatly reduced while the fire was actively burning. 2. Destruction of vegetation in the riparian zone reduced diurnal oscillation of flow rates. Flow rates quickly increased to points above protracted normal depletion rates but to varying degrees. No drastic immediate change in stream temperatures was noted.

A total of 292 Engelmann spruce were dissected and examined for decay and other defects in seven areas in the Blue Mountains of southeastern Washington and northeastern Oregon. Decay on a cubic-foot basis was 3.3 percent for pole trees and 5.4 percent for sawtimber. Defect loss in sawtimber spruce amounted to nearly 12 percent of the gross merchantable board-foot volume. Decay varied among study areas and could not be explained on the basis of age differences.

This paper presents the results of ground measurements of logging residue weights and volumes on 30 clearcut units in Douglas-fir forests of western Oregon and Washington. Additional information is given on quantities of material left as slash which might be utilized. These measurements were made on public lands, using a method developed in Canada.

A 26-year-old Tsuga heterophylla stand on the Oregon coast had a total biomass and current net annual production of 231.1 and 36.2 metric tons per hectare, respectively.

Calculated values of precipitation effectiveness index and temperature efficiency index for 48 weather observation stations on the Alaska mainland are used to delineate areas that have different climatic subclassifications during the wildfire season of April through September. The paper outlines procedures, provides maps showing step- by- step analysis along with the resulting areal boundaries, and suggests possible uses of the information.