白云山锐齿槲栎-华山松混交林优势种群空间格局分析

Spatial pattern analysis of dominant populations in mixed forest of Quercus aliena and Pinus armandii of Baiyunshan Mountain

【目的】确定锐齿槲栎(Quercus aliena)和华山松(Pinus armandii)优势种不同发育阶段的种群数量和分布格局及其种间竞争关系,对于二者合理间伐具有重要指导意义,有助于白云山针阔混交林群落的更新和稳定。【方法】调查研究区内锐齿槲栎-华山松混交林,将锐齿槲栎和华山松分为3个径级,分别归属为大树、中树、小树三个成长阶段,分别采用成对相关的g(r)函数和双变量g_(12)(r)函数对其空间分布格局和种内种间关系进行分析。【结果】在完全随机模型下,锐齿槲栎和华山松主要呈聚集分布并向随机分布过渡;在异质泊松模型下锐齿槲栎小树、华山松小树和中树呈聚集分布并逐渐向均匀分布过渡;锐齿槲栎中树和大树呈随机分布并逐渐过渡为均匀分布;华山松大树呈聚集分布并逐渐过渡为随机分布;在种内不同径级空间关联上,负相关主要集中在小树分别与中树、大树之间,中树和大树之间不存在竞争关系;在种间关联上,锐齿槲栎和华山松一直处于负相关关系。【结论】锐齿槲栎和华山松空间分布格局受密度制约,竞争关系在种内和种间均有体现。未来此区域的群落结构和种群空间格局将会向以锐齿槲栎为优势种、华山松优势不再明显的方向演变。

【Objective】To confirm the population number and distribution pattern of dominant species of Quercus aliena and Pinus armandii at different growth stages and their interspecific competition relationship has important guiding implications on reasonable thinning of both,which is helpful for the regeneration and stability of mixed broadleaf-conifer forest community of Baiyunshan Mountain.【Method】The Quercus aliena-Pinus armandii mixed forest of Baiyunshan Mountain was investigated,and the two dominant tree species were divided into three diameter levels,belonging to the big,middle and small growth stages,respectively.The spatial distribution pattern as well as intraspecific and interspecific relationships were analyzed by the Pairwise correlation g(r)function and bivariate g_(12)(r)function.【Result】Under the completely random model,the distribution of Quercus aliena and Pinus armandii were mainly aggregated and transferred to random distribution,but under the heterogeneous Poisson model,Quercus aliena small trees,Pinus armandii small trees and middle trees individuals were aggregation distribution and gradually transitioned to uniform distribution,the middle and big individuals of Quercus aliena gradually transitioned from random to uniform distribution,while the big individuals of Pinus armandii was aggregated and gradually transitioned to random distribution;In terms of spatial association of different diameter classes within species,the negative correlation was mainly between small and the middle as well as large individuals,respectively,but there was no competition between middle and big individuals;As regard with interspecific correlation,there was always negative correlation between these two species.【Conclusion】The spatial distribution pattern of Quercus aliena and Pinus armandii is restricted by density,and the competition were reflected both in intraspecific and interspecific.In the future,the community structure and population spatial pattern in this area will evolve in the direction that Quercus aliena is mainly as the dominant species and the dominance of Pinus armandii is no longer obvious.