. Forest mensuration. e empirical yield table for Western yellow pine, Coconino National Forest,Arizona, gives per cent of the normal or index yield. The stand of timber left on the cut-over areas, separated into three age classesby the method given in § 321 is fovmd. By dividing the stand for each age class by the yield per acre from the empirical3aeld table, the area which is stocked with timber, for each age class, is determined. The area reproduced to poles and saplings is estimated. The total area of cut-over land is known. The remaining area, not shown as stocked either with maturet
. Forest mensuration. e empirical yield table for Western yellow pine, Coconino National Forest,Arizona, gives per cent of the normal or index yield. The stand of timber left on the cut-over areas, separated into three age classesby the method given in § 321 is fovmd. By dividing the stand for each age class by the yield per acre from the empirical3aeld table, the area which is stocked with timber, for each age class, is determined. The area reproduced to poles and saplings is estimated. The total area of cut-over land is known. The remaining area, not shown as stocked either with maturetimber or young timber is the area cut clean and awaiting restocking. The resultsare given in Table LXVII. The prediction of growth is now made by applying the empiricalyield table to the areas and ages represented in the table. With the area and age of each age class indicated, the future yieldson cut-over lands may be predicted by applying the empirical yieldtable, increased by the per cent of expansion agreed Fig. 87.—Possibilities of Growthon Cut-over Areas. PLOTS FOR MEASUREMENT OF CURRENT GROWTH 443 TABLE LXVIIAreas Remaining Stocked on Cut-over Lands Class Yield peracre. Board feet Stand,total M. Board feet Empirical areaequivalent acres Per cent of 70,654 acres; also per cent of 1 acre Veteran Mature Blackjack Poles 300 200 100 50 20 0 12,050 16,750 7,480 27,900 9,702 70,908 2,315 579 9,493 6,006 17,663 34,598 8 5 Saplings Not 108,510 70,654 340. Permanent Sample Plots for Measurement of Current Growth. The best method of measuring the current growth of a stand is by meansof permanent sample plots, established in stands which are typical ofthe conditions to be studied, and re-measured at intervals of from fiveto ten years. Methods of establishing and measuring such plots aredescribed in § 243. In this way, just as for yield tables the actual netresults of all factors which affect the current growth o
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