Treesearch

Between the years 1913 and 1938, seven sets of permanent sample plots were established on the Whitman, Malheur, Rogue River, and Deschutes National Forests in eastern and central Oregon to study the results of various methods of selection cutting in old-growth ponderosa pine stands. This report briefly describes these studies and gives statistics on board-foot growth and mortality as related to method of cutting and other factors.

Successful day-to-day planning of presuppression activities requires accurate prediction of burning index. In the Pacific Northwest, forecasts of burning index are prepared by the fire-control man and are based on predictions of windspeed and fuel moisture. Although fuel moisture is affected by a number of weather elements and is consequently difficult to predict, the fire-control man can make satisfactory forecasts of fuel moisture by using the method described here.

In 1960, the first analysis of fire season weather was made for forests east of the Cascade Range. Highlights were: The 1960 season was among the most severe since 1939 in eastern Oregon, was more severe than normal in central Washington, and will long be remembered for the rainless lightning storm that hit northeast Oregon with devastating effect the evening of July 19.

The variation of fire-weather elements in mountainous terrain is complex at any one time, and the patterns vary considerably with time. During periods of serious fire weather, this variation becomes important. Much information is obtainable by local interpretation of available forecasts and observations. Optimum use of available information requires some understanding of basic meteorological processes and also demands adequate tools for application of the principles. This paper provides information about variation of midafternoon temperature and relative humidity in mountainous terrain and...

Current mortality in the Douglas-fir subregion, exclusive of catastrophic mortality, approximates a billion feet a year. The Forest Service report "Timber Resources for America's Future" recommended "...utilizing a substantial portion of the unsalvaged mortality loss..." as one means of permanently increasing the Nation's timber supply and bringing it into better balance with expected future timber requirements. Recovery of mortality from old-growth forests in the Douglas-fir subregion offers special opportunities for acting on this recommendation. Increased recognition of these opportuniti...

A 1-year study in the Blue Mountains of northeastern Oregon indicates that substantial amounts of soil moisture are consumed during the growing season in lodgepole pine stands. Dual purposes of the study were to estimate the quantities of water that can be stored in basalt-pumice soils typical of the Blue Mountains, and to determine the rate and amount of moisture depletion during the summer growing season. These are the first steps of an investigation to learn if cutting dense lodgepole stands will influence the amount of water available for streamflow.

This report assumes a knowledge of the principles of point sampling as described by Grosenbaugh, Bell and Alexander, and others. Whenever trees are counted at every point in a sample of points (large sample) and measured for volume at a portion (small sample) of these points, the sampling design could be called ratio double sampling. If the large sample is either a completely random or a systematic sample of the area being cruised, and if the small sample is either a completely random or a systematic sample from the large sample, formula 1 (below) is appropriate for calculating an estimate...

Information on the number of trees in a forest by diameter classes can add another useful dimension to the usual area and volume statistics about the forest resource.

This study investigated the feasibility of developing a technique for estimating site index of Douglas-fir in the Pacific Northwest, using aerial photos and topographic maps. Physiographic features were used as indicators of site index. Analysis showed that although most of the features were highly significant as criteria for predicting site index, they explained less than one-third of its variation. Equations, using the physiographic features as independent variables, were shown to be useful for estimating site index by a double-sampling procedure--particularly in relatively inaccessible...

This report presents the results of a study to determine the degrade (loss in volume and value) of western hemlock lumber cut, kiln-dried, and surfaced in accordance with commercial practice in western Oregon. The study measured (1) loss in volume due to culling and trimming surfaced dry lumber because of sawing, seasoning, and surfacing defects; (2) reduction in grade due to seasoning and surfacing defects; and (3) reduction in grade due to incomplete manufacture or the development of manufacturing defects. Degrade is expressed as a percentage of the rough green lumber volume and also as...