三峡库区次生黄栌灌木林的群落特征及种间联结性

以三峡库区次生黄栌(Cotinus coggygria)灌木林群落为研究对象,基于样地调查,分析了生境特征和群落特征。结果显示:该群落共有植物30科37属56种,物种组成简单、多样性低,群落中以喜光、耐干旱瘠薄和碱性土壤的物种居多。海拔和土壤有效磷含量是生境差异的重要因素;海拔、坡度和坡向对物种分布的影响最大。海拔与物种密度极显著负相关,坡向与物种高度极显著正相关;土壤pH与物种多样性和均匀度显著负相关,速效钾含量与物种密度呈极显著正相关,有效磷含量与物种丰富度和多样性显著正相关,与盖度显著负相关。综上,海拔、坡度和坡向是影响物种分布的因素;土壤有效磷和pH是影响物种多样性的因素;海拔、坡向、坡度、土壤有效磷和速效钾是影响群落数量特征的因素。群落总体关联性和物种种间联结性均呈显著负相关,种间联结较松散,处于不稳定的灌草阶段,生态系统脆弱,对生境变化十分敏感。因此,在对三峡库区黄栌群落进行生态修复时,应以保护现有群落及其生境为前提,选择适生乡土植物进行合理配置,增加物种多样性,促进群落演替。

Community characteristics and interspecific association of secondary Cotinus coggygria shrubbery in Three Gorges Reservoir Region

The habitat and community characteristics of the secondary Cotinus coggygria shrub community were analyzed based on field investigations in the Three Gorges Reservoir Region. Results showed a total 56 species belonging to 37 genera and 30 families in the community. Both the species composition and community were low. Light-liking, drought-tolerant, barren and alkaline soil-tolerant species were the majority in the community. Altitude and soil available phosphorus were the two most important factors resulting in habitat differences. Species distributions were significantly affected by altitude, slope and aspect. Species density significantly negatively correlated with altitude, while species height significantly positively correlated with aspect. Soil pH significantly negatively correlated with species diversity and evenness. Species density significantly positively correlated with available potassium. Both the species richness and diversity positively, while coverage negatively, correlated with available phosphorus. In summary, altitude, slope and aspect were the main factors affecting species distribution while soil available phosphorus and pH were the main factors affecting species diversity. Altitude, aspect, slope, soil available phosphorus and available potassium were the main factors that affected the quantitative characteristics of community. There was a significantly negative correlation between the overall interspecific associations of community and the interspecific association of species. The interspecific association was loose and in an unstable shrub-grass stage. The ecosystem was fragile and sensitive to the changes in habitats. In conclusion, for a combined strategies to protect the existing communities of C. coggygria and their habitats, to select the suitable native species for rational allocation, and promote the species diversity and community succession are timely needed for the ecological restoration of C. coggygria communities in the Three Gorges Reservoir Region.