古田山10种主要森林群落类型的α和β多样性格局及影响因素

古田山国家级自然保护区地处中亚热带, 地形复杂, 森林群落类型丰富。我们在保护区内10种主要森林群落类型中网格化布置并调查了79个20 m × 20 m样地, 分析了不同群落类型内及相互间的α (Shannon-Wiener指数)、β (Horn-Morisita相异性指数)多样性分布格局及其影响因素。结果表明: (1) α多样性主要受到群落类型、海拔和坡向的影响。α多样性在不同群落类型间差异显著, 并且随海拔升高、坡向从南到北, α多样性增大。(2) β多样性主要受到群落类型和海拔的影响, 受空间距离的影响不显著。不同群落类型间的β多样性显著大于同一群落类型内部, 并且随海拔升高β多样性增大。总体而言, 群落类型和海拔是古田山森林群落α和β多样性的主要影响因子, 表明生境过滤等机制对该区域的森林物种多样性格局起着主要作用。

Drivers and patterns of α- and β-diversity in ten main forest community types in Gutianshan,eastern China

Located in the subtropical zone of China, Gutianshan National Nature Reserve (GNNR) contains a variety of forest community types and is rugged in terrain. Here, we established 79 forest plots, each 20 m × 20 m in area, within the ten main community types of GNNR. Based on this, we analyzed the α- (Shannon- Wiener index) and β- (Horn-Morisita dissimilarity index) diversity patterns of and between these community types and their underlying driving factors. We found that: (1) Community type, elevation and aspect were the most important determinants of α-diversity. α-diversity showed significant differences between community types, and increased with elevation and northness. (2) Community type and elevation, but not spatial distance significantly affected β-diversity. β-diversity between community types was higher than within community type, and β-diversity also increased with increasing elevation. These results show that community type and elevation are the main influencing factors of the α- and β-diversity patterns in GNNR forests, and further suggest the importance of drivers, such as habitat filtering, on the assembly of GNNR forests.