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目前各种资料求测森林郁闭度记载有四种方法:(一)标准地实绘树冠投影图;(二)压线法;(三)凭人的感观目测;(四)统计法。标准地绘树冠投影图,只适宜在特殊情况下(如科研实验基地的郁闭度测量)使用,但难度很大,且费工费时;凭人的感观估测,误差常在0.1～0.2之间,一般难以得到予想的结果;压线法虽简单易行,但在复层林和人工林间伐不及时,树高生长参差不齐的情况下,很难找到具有代表性的样线;统计法是在林内设样点,操作是比较复杂的。
At present, there are four methods for determining the forest canopy density by various data: (1) standard projection map of canopy; (2) pressure line method; (3) visual observation with human senses; (4) statistical method. Canopy projection standard map, only suitable for special circumstances (such as scientific and experimental test of canopy density measurement) to use, but difficult, and time-consuming work; with people’s perceptions, the error often in the 0.1 to 0.2 Is generally difficult to get the desired result; although the pressing method is simple and easy, it is difficult to find a representative sample line in the situation that the interstory and artificial forests are not thinned in time and the height of the tree grows uneven; Law is set in the forest samples, the operation is more complicated.