小兴安岭针阔混交林乔木层优势树种种间联结

Inter Species Linkage of Dominant Tree Species in the Tree Layer of Coniferous and Broadleaved Mixed Forest in Xiaoxing'an Mountains

【目的】揭示小兴安岭针阔混交林未来的演替趋势和各物种间的种间关系,为小兴安岭针阔混交林的森林可持续经营和维持群落稳定性提供科学的理论依据。【方法】利用方差比率法(VR)、χ^(2)检验、联结系数AC和Pearson相关检验等方法对小兴安岭针阔混交林乔木层优势树种136个种对的种间联结测定和分析。【结果】小兴安岭针阔混交林乔木层优势树种总体联结性VR>1,χ^(2)_(0.95)(25)<χ^(2)<χ^(2)_(0.05)(25),乔木层优势树种总体表现为不显著的正联结;χ^(2)检验显示,在10 m×10 m样方尺度下,17个优势树种组成的136个种对中,118个种对呈无显著关联,4个种对显著正联结,2个种对极显著正联结,8个种对显著负联结,4个种对极显著负联结;联结系数AC显示,60个种对呈正联结,76个种对呈负联结;Pearson相关系数检验显示,55个种对呈正相关,81个种对呈负相关;χ^(2)检验、联结系数AC和Pearson相关检验结果基本一致。【结论】小兴安岭针阔混交林种间联结性较弱,群落各物种间总体上呈独立分布格局,群落演替正处于相对稳定的阶段,群落乔木层优势树种间正联结的种对少于负联结的种对,群落内负相互作用占优势,但这种负相互作用的强度较低。

【Objective】This study aimed to reveal the future succession trend and interspecific relationships of the mixed coniferous and broad-leaved forest in Xiaoxing'an Mountains,in order to provide a scientific theoretical basis for the sustainable management and maintenance of community stability in the mixed coniferous and broad-leaved forest of Xiaoxing'an Mountains.【Method】Using methods such as variance ratio(VR),chi square test,association coefficient AC,and Pearson correlation test,interspecies associations of 136 dominant tree species in the tree layer of the Xiaoxing'an Mountains coniferous and broad-leaved mixed forest were determined and analyzed.【Result】The overall connectivity VR of dominant tree species in the coniferous and broad-leaved mixed forest of Xiaoxing'an Mountains was greater than 1,χ^(2)_(0.95)(25)<χ^(2)<χ^(2)_(0.05)(25).The dominant tree species in the tree layer generally exhibited insignificant positive connectivity.According to theχ^(2)test,at the 10 m×10 m plot scale,out of 136 species pairs composed of 17 dominant tree species,118 types of pairs showed no significant correlation,4 types of pairs showed significant positive correlation,2 types of pairs showed extremely significant positive correlation,8 types of pairs showed significant negative correlation,and 4 types of pairs showed extremely significant negative correlation.Pearson correlation coefficient test showed that 55 types of pairs were positively correlated and 81 types of pairs were negatively correlated.The results of theχ^(2)test,association coefficient AC,and Pearson correlation test were basically consistent.【Conclusion】The interspecific connectivity of the mixed coniferous and broad-leaved forest in Xiaoxing'an Mountains was weak.The overall distribution pattern among species in the community was independent.Community succession was in a relatively stable stage.The number of positively connected species in the dominant tree layer of the community was less than the number of negatively connected species,and negative interactions within the community were dominant,but the intensity of these negative interactions was relatively low.