Treesearch

Estimates of breast-height diameter outside bark for trees as of some previous date are required in certain kinds of forest growth studies. These past diameters may be found by subtracting total diameter growth from known present diameters, where total diameter growth is the sum of wood growth and bark growth. Wood growth is readily obtained by measuring the combined width of a given number of annual rings on cores extracted from trees. Bark growth, however, must be approached indirectly by some procedure like the one to be described.

Natural reproduction has often proved undependable for restocking cutovers and burns in the mixed-conifer forest types of southwestern Oregon. These types, covering 6,000 square miles of productive forest land in the five southwestern Oregon counties, are composed of many species--principally Douglas fir, Pseudotsuga menziesii (Mirb.) Franco; ponderosa pine, Pinus ponderosa Laws.; sugar pine, Pinus lambertiana Dougl.; incense cedar, Libocedrus decurrens Torr.; grand fir, Abies grandis (Dougl.) Lindl.; and white fir, Abies concolor (Gord. & Glend.) Lindl. Each of these species is commerciall...

Interest among foresters in forest tree improvement has increased rapidly in recent years. Geneticists have learned that some individual trees greatly excel their neighbors in desirable characteristics, and that some entire stands are superior to other stands of the same species in a general locality. They have learned that many of the desirable tree characteristics are hereditary in nature, and they have reasoned and shown that man may profit greatly by planned improvement of forest trees.

Newly-formed sapwood of young conifers has probably been a food for bears since time immemorial, but damage to trees has only recently attracted the attention of foresters. In many localities, all stages of bear-caused wounds can be found, from fresh ones to those covered with callus, On a 3-acre clear-cut, made in 1950 in a rather open part of the 110-year-old stand of Douglas-fir on the Wind River Experimental Forest, 107 trees out of a total of 132 were found to have been wounded between 1854 and 1918. More than two-thirds of the wounds were made between 1865 and 1885--that is, when the...

Test plantings have been made on the Hemlock Experimental Forest in cooperation with the St. Regis Paper Company to test suitability of several native conifers for planting on heavy bracken and brush-covered Site II areas typical of the western Olympic Peninsula. In the spring of 1950, 2,500 Douglas-fir seedlings from the Forest Industries Tree Nursery at Nisqually were planted. In 1952, planting was continued with 1,000 Sitka spruce, 500 grand fir, and 1,000 western redcedar from the U. S. Forest Service Nursery at Wind River, and in 1953 with 2,500 western hemlock, a gift of the British...

For the third successive year mid-fire-season fuel moistures on national forests of Oregon and Washington averaged higher than in the preceding year, and forest flammability was correspondingly lower. Generally high fuel-moisture conditions during 1954 are reflected in fire occurrence, which approached an all-time low. Fuel-moisture ratings are based on the 25 lowest daily observations of fuel-moisture indicator sticks in the period July 16 to August 31. Records are from 65 fire-danger stations near the exterior boundaries of the national forests (table 1).

Four years' measurement of seed fall in the spruce-hemlock type on the Cascade Head Experimental Forest indicates that an ample supply of seed is distributed over clear-cut areas under staggered-setting cutting. The largest tract sampled was 81 acres; in spite of a seed crop failure in 1950, it received an average of 243,000 viable spruce and hemlock seeds per acre yearly on a high ridge near the center of the area. In the spruce-hemlock type it is apparently practical to clear cut fairly large openings and still depend upon adjacent stands for an adequate distribution of seed.

In 1952 and 1953 cooperative research was conducted by the Pacific Northwest Forest Experiment Station and the Research Department of Weyerhaeuser Timber Company to obtain information concerning the rate of deterioration of beetle-killed Douglas-fir. The study was prompted by an outbreak of the Douglas-fir beetle that developed in 1951 and has since killed an estimated nearly 2 billion board feet of timber over an area of some 4,800,000 acres in western Oregon and southwest Washington. In order to salvage a maximum amount of the insect-killed timber the timber industry needs to know how...

The expected growth of pole-size ponderosa pine on cutover land should be considered in selecting those trees which will grow fast enough in the future to warrant investment in pruning. This consideration is especially important because most pruning work is done within 2 or 3 years after cutting and before the release effect of cutting is evident on reserved trees.

Evaluating the effects of slash burning on regeneration and tree growth is one of the most pressing forest soil problems in the Douglas-fir region. Extensive literature concerning burning and soils is available for other parts of the world, but conclusions are not directly applicable to the Pacific Northwest. Here several studies are under way or planned to determine the effects of slash burning on soil quality, regeneration, and tree growth. This research note covers only the effect of slash burning on soil pH; this information will eventually be combined with findings from related studies.