近自然经营对马尾松林优势树种生态位及种间关系的影响

Influence of Close-to-nature Management on the Ecological Niche and Interspecific Relationships of Dominant Tree Species in Pinus massoniana Forests

探究近自然经营对马尾松林的生态位和种间关系的影响,可以为经营管理提供实践基础和科学依据。以实施近自然经营10余年的马尾松林为研究对象,分别从幼苗(胸径<1 cm)、幼树(1 cm≤胸径<5 cm)和成树(胸径≥5 cm)3个阶段,探讨近自然经营对马尾松林12个优势树种的生态位及种间关系的影响。结果显示:(1)马尾松在成树和幼树阶段的生态位宽度变小,幼苗和大部分优势树种的生态位宽度增加;(2)各优势树种种对间生态位重叠度变小,生态位分化程度增加;(3)群落总体关联性大多呈现正关联,但极显著正联结种对较少;Spearman秩相关检验结果显示不同生长阶段经营和对照林分种对间存在差异但并不显著。综上,研究区马尾松林仍处于演替初期,群落结构不稳定,近自然经营对马尾松林种间关系的改善具有一定效果但并不理想,建议针对研究区纯林化程度过高且密度过大的马尾松林分,在密度调控的基础上结合林下补植枫香和麻栎、白栎等栎类树种,加速群落演替,尽快实现改善种间关系和提升群落稳定性的目的。

In order to explore whether close-to-nature management can effectively improve the ecological niche and interspecific relationships of Pinus massoniana forests,and provide practical basis and scientific evidence for management,this study focused on implementing close-to-nature management in P.massoniana forests for over 10 years.Three growth stages were considered:seedlings(D<1 cm),young trees(1 cm≤D<5 cm),and mature trees(D≥5 cm)to investigate the impacts of close-to-nature management on the ecological niche and interspecific relationships of 12 dominant tree species in P.massoniana forests.The results showed that:(1)Close-to-nature management effectively reduced the Niche width of P.massoniana in the community at the stage of mature trees and young trees ,while increasing the Niche width of P.massoniana seedlings and other dominant tree species;(2)Close-to-nature management significantly decreased the ecological niche overlap among dominant tree species and increased the degree of niche differentiation;(3)The overall correlation of the community mostly showed positive associations,but there were relatively few significantly positive associations between specific species pairs.s pearman test resultsalso reflected that there were some differences but not significant between the managed and control stands at different growth stages ,indicating that the improvement effect of close-to-nature management on interspecific relationships in P.massoniana forests was not ideal.In conclusion,the P.massoniana forests in the study area are still in the early stage of succession with unstable community structure.There is a certain effect on the improvement of interspecific relationships through close-to-nature management,but it is not evident.It is recommended to address the issue of high pure stands and excessive density in the P.massoniana forests in the study area.On the basis of density regulation,understory planting of Liquidambar formosana and oak species such as Quercus acutissima and Q.fabri should be combined to accelerate community succession and achieve the goal of improving interspecific relationships and enhancing community stability as soon as possible.