紫金山落叶阔叶林主要树种空间分布格局及种间关联性

Spatial distribution and interspecific association of main tree species ina deciduous and broad-leaved forest in the Purple Mountain

【目的】探讨我国北亚热带落叶阔叶林主要树种的空间分布格局及种间关联性,揭示当前群落演替趋势,为紫金山森林群落的科学管理以及南京丘陵地带的森林植被恢复提供依据。【方法】以南京市紫金山落叶阔叶林为研究对象,采取相邻格子样方法先划分10 m×10 m的调查样方,再在每个调查样方的对角线建立2 m×2 m小样方(4个角及中心),采用每木调查法确定落叶阔叶林中各树种的重要值,进而确定该群落内重要值前7位的主要树种,并分析了这些主要树种在100 m^(2)林分尺度下种群的胸径分布、空间分布状况以及种间关联性。【结果】(1)紫金山南坡落叶阔叶林主要树种为糙叶树、朴树、山胡椒、黄连木、马尾松、枫香和栓皮栎。其中朴树和山胡椒为进展种群,糙叶树、黄连木、枫香和栓皮栎为稳定种群,针叶树马尾松为衰退种群。(2)主要阔叶树种群的空间格局为集群分布,聚集程度依次为山胡椒>朴树>黄连木>枫香>栓皮栎>糙叶树;先锋树种马尾松则为均匀分布。(3)7个主要种群间的整体关联性为显著正关联;其中不同树种间的正联结有14个,负联结有7个,且均不显著。【结论】在自然演替过程中,紫金山落叶阔叶林乡土落叶阔叶树种占据主要地位,群落仍处于进展演替的动态变化阶段。

【Objective】This research explored the spatial distribution of dominant tree species and their interspecific correlation and revealed the typical community succession in north subtropical secondary forests in China to provide basis for scientific management of forest community in the Purple Mountain and of forest vegetation restoration in the hilly area of Nanjing.【Method】The adjacent lattice method was used to divide the survey samples of 10 m×10 m,and 2 m×2 m small samples(4 corners and centers)at the diagonal line of each survey sample were established in the deciduous broad-leaved forest of the Purple Mountain.The per-tree survey method was used to determine the importance value of each tree species,and main tree species with top 7 important values were determined.The diameter at breast height(DBH)distribution of trees,cluster-intensity of spatial pattern and interspecific connection coefficients at the scale of 100 m^(2) were analyzed.【Result】(1)The main tree species in the deciduous broad-leaved forest on the southern slope of the Purple Mountain included Aphananthe aspera,Celtis sinensis,Lindera glauca,Pistacia chinensis,Pinus massoniana,Liquidambar formosana and Quercus variadilis.Celtis sinensis and Lindera glauca were progressive populations,Aphananthe aspera,Pistacia chinensis,Liquidambar formosana and Quercus variadilis were stable populations,while Pinus massoniana was declining population.(2)The spatial pattern of main broad-leaved tree populations was cluster distribution with spatial aggregation in decreasing order of Lindera glauca>Celtis sinensis>Pistacia chinensis>Liquidambar formosana>Quercus variadilis>Aphananthe aspera.Pinus massoniana was classified as even distribution.(3)The seven main populations had significantly positive correlations with each other.The correlations of species pairs were insignificant with 14 positive and 7 negative.【Conclusion】In the process of natural succession of the deciduous broad-leaved forest in the Purple Mountain,the native deciduous broad-leaved tree species dominated and the community was still in dynamic changing stage of the progression succession.