次生林林木分级指数及其应用

为了更加科学、准确的评价林木在林分中的位置优劣状况,为林木分级提供新方法。以芦头国有林场青冈栎次生林为例,提出林木分级指数概念,筛选得到大小比数、健康指数、空间密度指数、混交度、交角竞争指数5个指标来构建林木分级指数计量模型,基于层次分析法,得到林木分级指数的计量模型为TCI=0.368 3(1-U)+0.279 2H+0.147 9(1-UCI)+0.136 4(1-D)+0.068 2M。采用等间距法得到每个林木等级的林木分级指数值分别为:优势木(0.75~1],亚优势木(0.5~0.75],中庸木(0.25~0.5],被压木(0~0.25]。运用指数计量模型计算得到芦头国有林场2个样地的林木分级指数均值分别为0.602 1和0.583 4,表明2个样地优势木和亚优势木均较多,林木总体生长状况较好。

Tree classification index of secondary forest and its application

In order to evaluate the strengths and weaknesses situation of trees in the forest stand more scientificly and accurately, a new method for trees classification was provided. It took the Cyclobalanopsis glauca ( Thunb.) Oerst. secondary forest in Lutou forest farm as an example, put forward tree classification index concept, screened out neighborhood comparison, healthy index, spatial density index, mingling index, angle competition index to build tree classification index measuring model based on AHP. As a result, the tree classification index measuring model was TCI=0.368 3(1-U)+0.279 2H+0.147 9(1-UCI)+0.136 4(1-D)+0.068 2M. According to the method of equal space, the tree classification index value of each level was worked out: dominant tree(0.75~1], subdominant tree(0.5~0.75], intermediate tree(0.25~0.5], suppressed tree(0~0.25]. The mean value of tree classification index of the two samples in Lutou forest farm were calculated as 0.602 1 and 0.583 4, respectively, using the tree classification index model. It showed that growth condition of the forest stand was good since the majority trees in two samples were dominant and subdominant trees.