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below: Broadcast over Seedspots, Species. entire area. Strips. 6' apart. Douglas fir $3.20-4.75 $1.00-2.60 $2.75-6.00 Yellow pine 5.20-6.25 1.85-2.35 2.75-6.00 Western white pine 4.70-6.25 2.00-2.40 2.75-6.00 RATE OF GROWTH AND PROBABLE RETURNS Of all factors in calculating the financial possibilities of second forest crops, the growth to be expected is the easiest to determine with fair accuracy. Future stumpage value, tax burden and fire risk are all subject to uncertain influences, but the approximate yield of a given species under given natural conditions will be the same in the future that it is now. To predict it requires only study of existing stands without being misled by the influence of conditions which will not be repeated. On the other hand, an immense amount of misinformation is circulated because of superficial observation. Enthusiasts discovering individual trees which have made prodigious growth, or even fairly extensive stands on fertile soil with heavy rainfall, will compute sawlog yields at 40 or 50 years which are much too optimistic for general application. Others, remembering some stand they have seen in unfavorable localities, or noting shade-suppressed trees which will not be paralleled after the virgin forest is removed, are unduly discouraged. It is most essential that yield tables be made by trained observers who know how to reach the true average, and that the figures either actually come from the region to which they are to be applied or are accompanied by a systematic analysis of climatic and other conditions which permits intelligent comparison. In calculating another yield on cut-over land, the system for an even-aged new growth, such as will follow clean cutting of Douglas fir, for example, is quite different from that necessary if the cutting amounts only to selection of the merchantable trees and leaves a fair stand of smaller ones. In the latter case, yield tables based on average acreage production are of little use because so much depends upon the character of the stand which remains on the tract in question. Here the basis must be the rate of growth of the average individual tree. An estimate by the number in each present diameter class may be made of the trees which will escape logging, showing, let us say for example, about five trees of each diameter from 6 to 12
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