Treesearch

In 1937 normal yield tables were compiled by Meyer for even-aged stands of Sitka spruce and Western hemlock. The basic data from which the tables were compiled were collected over the entire coastal range of the species, extending from southern Oregon through Washington end British Columbia to southeastern Alaska. Data were obtained from temporary sample plots established in even-aged stands, the composition by species varying from pure hemlock to pure spruce. Douglas-fir and Western redcedar occurred to a minor extent on many of the plots.

The increasing importance of red alder as a commercial species in the Pacific Northwest has prompted the three agencies listed above to pool their tree measurement data for the construction of standard regional red alder volume tables. The tables included here were based on trees from a variety of sites and form classes. Approximately one quarter of the total number of tree measurements came from British Columbia.

The organic material supplied the forest soil by deposits of needles, deadwood and roots, and soil insect remains, decomposes to form humus, defined as the plant and animal residues of the soil, fresh surface litter excluded, which are undergoing evident decomposition (2). This decomposition is necessary before the nutrient elements contained in the organic litter can become available for use by plants.

The international log rule is little used in the Douglas-fir region today, but it is likely to find wider use here in the future. This is the opinion of a number of foresters preparing plans for the management of forest properties in the region. Advantage of the International 1/4-inch kerf log rule is that log scale by this measure approximates the volume of green lumber recovered by sawmills of average efficiency and cutting a normal mill-run of lumber sizes.

During recent years the sale of timber from national forests in the Douglas-fir region has developed into big business. As the demand for stumpage steadily increases, and the allowable annual cut is approached or reached on a number of working circles, sale administration problems also increase and become more complex.

Some cut or burned-over Douglas-fir areas restocked promptly and fully. Others do not and seemingly never will restock adequately without the help of artificial seeding or planting. On some areas widely scattered seedlings become established and grow; filling-in is by second generation trees from the seed of these scattered parents. On still other areas stocking improves gradually over a period of years. The apparent inconsistencies and wide differences in rates of restocking are often disconcerting to the forester striving for stands of good density, and trying to determine if he should...

A stand-improvement study in century-old Douglas-fir at the Wind River Experimental Forest provides an example of a commercial thinning that gave a substantial intermediate harvest, salvaged considerable material that would have been lost through mortality, greatly increased the net growth rate, and improved the general vigor of the stand, leaving the forest in a more healthy condition.

The forest fire season of 1948 in Oregon and Washington was regarded by fire suppression agencies as the most favorable for many years. The number of fires started and area burned were, in general, less than for many years. On the national forests the number of fires was the least since 1912 and the acreage burned was the least ever recorded. Was this primarily due to favorable fire weather conditions or to better fire prevention and suppression? Experienced fire fighters recognized at the time that periods of unusually dry weather which usually bring with them numerous accidental fires...

One of the aims of selection cutting in ponderosa pine forests is to reduce the heavy mortality, from bark beetle attack and other causes that is common in most virgin stands. How much the loss can be reduced is shown by a 10-year record at the Pringle Falls Experimental Forest in central Oregon. Here selection cutting has reduced loss on cutting areas to only about one-sixth of the loss on an uncut check area.

Measuring heights of Douglas-fir trees for the determination of site index is a time-consuming job, especially in dense stands. Both dominant and codominant trees must be measured since site index curves represent the average height of dominants and codominants. It has been suggested that considerable time might be saved if only dominant trees were measured, since these trees extend above the general crown level and are frequently in or at the edge of openings; hence, their tops are much more easily spotted from a distance.