茂兰喀斯特森林不同地形部位木本植物种间联结性分析

Interspecific Association of Woody Plant Species at Different Topography Sites in Maolan Karst Forest

选择茂兰国家级喀斯特森林自然保护区内木本植被为研究对象,对区内3种地形(槽谷、坡地、漏斗)中的植被进行群落学调查。通过重要值计算结果在每个地形群落中各选取了42个优势种,运用多物种总体联结性,各物种间联结性、联结系数、共同出现百分率等指数,对不同地形部位群落的种间联结性进行分析。结果表明:1)研究区群落总体呈不显著正联结关系,与种对间联结性特征一致,群落中各种群趋于独立出现,群落处于比较稳定的阶段。2)不同地形部位群落的种间联结性存在一定差异。槽谷、漏斗群落总体呈不显著正联结,正联结种对较多;坡地群落总体呈不显著负联结,负联结和无联结种对较多。3)槽谷、漏斗群落种间联结性较高,群落结构较稳定,坡地群落种间联结性较低,群落结构不稳定。由以上群落种间联结特征推断植物种间松散的联结关系是喀斯特森林物种的共存机制之一,这种共存机制在不同地形部位群落中有不同的表现形式。

Based on investigation on the communities, the woody plant species at three topography sites in Maolan National Nature Reserve were selected as the object of research. Through the calculation of important values, forty-two dominant species were selected in each communities. Overall association, interspecif- ie association,percentage co-occurrence （PC） and association coefficient（ AC ） were used to analyze the interspecific association of these dominant species. The results showed that： （1） overall association of community in research area was insignificant positive association and it was in accord with interspecific association. Populations were easy to arise independently. Community was in a relatively stable stage. （2） the interspecific associations of communities at different topography sites were different. In funnel and valley communities, overall association was insignificant positive association, and more species-pairs had positive correlation. In hillside community, overall association was insignificant negative association, and more species-pairs had negative correlation or no correlation. （3）There was higher association among the species-pairs in the funnel and valley communities, and community structure was relatively stable. There was lower association among the species-pairs in the hillside community, and community structure was relatively unstable. Through the interspeeific associations of communities, a concluson can be drawn that the loose interspecific relationship may be one of the coexistence mechanisms of karst forest species. There were different forms of the coexistence mechanism in the communities at different topography sites.