金沟岭林场云冷杉天然次生林空间结构

Stand Spatial Structure of Natural Mixed Spruce-Fir Secondary Forests in Jingouling Forest

以构建Voronoi多边形和建立TIN三角网空间连接确认空间结构单元,采用混交度、大小比数、聚集指数、竞争指数和空间密度指数,分析汪清县金沟岭林场典型云冷杉天然次生林的结构特征。结果表明:云冷杉最常见的结构单元为1株中心与5株相邻木;林分平均混交度为0.71,树种隔离程度较高,属强度混交状态;林分平均胸径大小比数为0.513,林木处于中等竞争,林分大小分化适中;主要树种的竞争强度由大到小排序为冷杉、红松和云杉,冷杉作为优势树种竞争力强,生长活力一般;林分平均聚集指数为1.059,空间密度指数为0.521,林分整体处于随机向均匀分布过渡的状态;椴树、枫桦、红松、冷杉和云杉作为中心木,其周围的邻近木处于随机分布状态,其他树种单元处于均匀分布。

Spatial structure(including mingling,neighborhood comparison,aggregation index,competition index and spatial density index)of a typical natural mixed spruce-fir forest in Jingouling Forest Farm of Wangqing County was analyzed by Voronoi polygons and the TIN triangulation.The most common structural unit of spruce-fir forest is one center tree with five neighbor trees.The average mingling of stand was 0.71,and the degree of segregation among tree species was high in the mixed state of intensities.The average neighborhood comparison based on DBH was 0.513,indicating the forest was in a middle level of competition,and the differentiation of stands was not significant.The descending order of the competition intensity of mainly species was fir,Korean pine and spruce,and fir was the dominant species with strong competition but growing vitality was not high.The average aggregation index of the stand was 1.059,the spatial density index was 0.521,and the spatial pattern of forest trees were in a state of random transition to uniform distribution.With the linden tree,maple birch,Korean pine,fir and spruce as the center tree,the neighbor trees displayed a random distribution pattern,but other species units were uniformly distributed.