秦岭山地油松天然次生林灌木层主要种群种间联结性与功能群划分

Interspecific association and functional group classification of the dominant populations in shrub layer in secondary forest of Pinus tabuliformis in Qinling Mountain,China

运用χ~2检验、联结系数和共同出现程度,测定秦岭山地油松天然次生林灌木层20个主要植物种群的种间联结性.结果表明:在190个种对中,具有较明显正联结的种对数占总种对数的7.4%,胡枝子与胡颓子、漆树与油松、卫矛与毛樱桃等表现为极显著正联结,绝大多数种对表现为弱联结,正负联结比值均小于1.表明灌木层主要植物种群种对间联结较松散,物种之间存在一定的独立性,处于动态演替的中期阶段,群落稳定性较差.通过种间联结和聚类分析,结合生物学和生态学特征,将灌木层20个主要植物种群划分为4个功能群.同一功能群内物种的生态要求和资源利用方式相近,联结紧密,而不同功能群间联结较为松散.

We analyzed the interspecific association among 20 dominant populations in shrub layer in secondary natural forest of Pinus tabuliformis in Qinling Mountain,China,with χ^2-test,the association coefficients and the percentage of common occurrence. The results showed that the species pairs with significant positive associations accounted for only 7. 4% of the total 190 species pairs.The species pairs such as Lespedeza bicolor and Elaeagnus pungens,Toxicodendron vernicifluum and Pinus tabuliformis,Euonymus alatus and Cerasus tomentosa had extremely significant positive correlations,whereas most of the species pairs showed weak interspecific association. The ratio of positive and negative correlations was less than 1. The results suggested that the interspecific association was relatively weak. Species were with certain independence among dominant populations. Community structure was at an unstable mid-stage with dynamic succession. According to the interspecific association and cluster analysis,combined with biological and ecological characters,the 20 dominant populations in shrub layer were classified into four functional groups. The ecological requirement and resource use pattern of species within the same functional groups were similar,exhibiting a close connection between the shrub species. The connection between different functional groups was relatively loose.