摘要:
以福寿国有林场24 年生杉木生态公益林为研究对象,通过Voronoi 图确定林分基本空间结构单元,确立各中
心木的邻近木,计算混交度、大小比数、聚集指数和林层指数,量化分析了群落的林分空间结构特征。结果表明:1)
群落内共存在9 种不同大小的空间结构单元,其中以1 株中心木与5 株邻近木的形式最为常见;2)林分平均混交
度为0.23,为弱度混交,不同树种间的相互隔离程度较低,空间配置较为简单;3)林木大小比数分布存在波动性变
化,乔木层树种稳定性大;4)林分平均聚集指数为1.01,林木水平分布格局正处于由团状分布向随机分布演替的过
渡阶段;5)林分平均林层指数为0.23,林木垂直方向上分层较为简单。
Abstract:
To analyze the spatial structure of Cunninghamia lanceolata non-commercial forest, the plantation
predominanted by the 24-year-old C. lanceolata located in Fushou Forest Farm of Yueyang City, Hunan
Province of central China was taken as the study object, and four structural parameters, i. e. mingling
degree, neighborhood comparison, aggregation index and storey index, were calculated based on the
Voronoi diagram that can determine the reference tree爷s neighborhood groups of trees. The results showed
that: 1) there were nine kinds of different sizes of spatial structure unit in this community, and the most
common phenomenon was that the reference tree had five close neighboring trees; 2) the average
mingling degree of stand was 0.23, indicating the simple spatial allocation and poor mixing of different
tree species; 3) the distribution of neighborhood comparison based on DBH changed with a fluctuant
pattern, and the stability of species in the arborous layer was good;4) the average aggregation index of
stand was 1.01. The individuals of tree presented the succession trend from aggregated distribution to
random distribution; 5) the average storey index of stand was 0.23, and the spatial configuration was
relatively simple in the vertical space.