末口係数による立木利用材積の測定法

概要

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I devised Top-end Coefficient Method for measuring the utilizing volume of standing trees. For the purpose of determining the Top-end Coefficient, 50 standing trees were selected by the table of random numbers from the Cryptomeria stand which was exist at V forest compartment in Yamagata Pref. The stand consists of trees, being 40 years of age, 19.23 m in average height and 26.0cm in average d. b. h.By this method, the top-end diameter of sectional log per 2 meters can be measured by multiplying the Top-end Coefficient (t_n) to d. b. h. (D_<1・2>). So I named this t_n "Top-end Coefficient". Then we can calculate D_<2n>, Which is the top-end diameter sectioned per 2 meters as follows : t_1=D_<2・0>/D_<1・2>, t_2=D_<40>/D_<1・2>, …t_n=D_<2n>/D_<1・2> hence, D_<2・0>=D_<1・2>・t_1,D_<4・0>=D_<1・2>・t_2,‥D_<2n>=D_<1・2>・t_n n=1,2,3,…8.These results of "t_n" and its practical value are shown in Tab. 3 & 4. The utilized log volume of standing tree can be calculated by suming up the volume of each log which will be found in the log table.The difference between the Top-end Coefficient Method and the Measued Method is very little, and the errors-rate in case of 50 standing trees is -1.39% per 25.815 m^3 as shown Tab. 5 & 6.I can say, therefore, that this method is more practical one for buying and selling the standing trees.
日本森林学会の論文
1953-05-25