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一、林分表法林分表法是在美国采用的一种方法。本法首先要进行每木调查,作出各径阶的株数分配表,再作出树高曲线。据上述资料查立木材积表,计算现在的材积 V。然后,就任意挑选一些林木,用生长锥分别径阶测定一定期间(5年或10年)的直径生长。据此再制出一定期间后的各径阶株数分配表。并假定这个期间直径对树高的关系没有变化。同样使用前面的树高曲线和立木材积表,查算出这个一定期间后的林分材积 V′。于是,这个一定期间的生长量 Z 可由下式求出:
First, the forest table Farnell table method is used in the United States a method. This law must first conduct a survey of each wooden, make the order of the number of branches of different orders, and then make the tree height curve. According to the above information to identify timber volume table, calculate the current volume V. Then, we randomly selected some trees and measured the diameter growth of the trees by growth cone for a certain period of time (5 years or 10 years). Accordingly, a certain period of time after the number of strains of different sizes distribution table. It is assumed that there is no change in the relationship between diameter and tree height during this period. Also use the previous tree height curve and stand volume tables to find out the stand volume V after this period. Thus, the growth of this period of time Z can be obtained by the following formula: