Biodiv Sci ›› 2017, Vol. 25 ›› Issue (1): 23-33.DOI: 10.17520/biods.2016199

• Orginal Article • Previous Articles     Next Articles

Spatial heterogeneity and its causes in evergreen broad-leaved forests in the Ailao Mountains, Yunnan Province

Yuanjie Xu1, Dunmei Lin2, Ming Shi3, Yanjie Xie3, Yizhi Wang1, Zhenhua Guan1,*(), Jianying Xiang1   

  1. 1 Yunnan Academy of Biodiversity, Southwest Forestry University, Kunming 650224
    2 Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044
    3 The Faculty of Forestry, Southwest Forestry University, Kunming 650224
  • Received:2016-07-20 Accepted:2017-01-05 Online:2017-01-20 Published:2017-02-08
  • Contact: Guan Zhenhua

Abstract:

Understanding the variation of species richness over spatial scales, and elucidating the response of plant community composition to habitat heterogeneity has been one of the major topics in the study of community ecology. Niche differentiation related to habitat heterogeneity plays an important role in shaping diversity levels and species distribution patterns of plant communities. Based on a survey of 42 plots of four types of evergreen broad-leaved forests in the Ailao Mountains of Yunnan Province, this paper explored how community distribution and tree species richness of such forests changed along topographic and edaphic gradients. We found significant differences in community composition among the four types of evergreen broad-leaved forests. Tree species richness of monsoon evergreen broad-leaved forests was significantly higher than that of the other forest types. Tree species richness of mid-montane moist evergreen broad-leaved forests was significantly higher than that of semi-humid evergreen broad-leaved forests, whereas no significant difference was observed among the other forest types. Non-metric multidimensional scaling (NMDS) revealed that nine environmental gradients, including elevation, slope, soil water content, soil organic matter, were the determinants of forest community composition and tree distribution patterns. As the best predictors of tree species richness, soil available boron, elevation, soil total potassium and convexity together explained 63.2% of the variance of tree species richness. The combination of topographic and edaphic factors explained most of the variance of community composition and tree species richness of the evergreen broad leaved forests in the Ailao Mountains.

Key words: habitat heterogeneity, community composition, tree species richness, evergreen broad-leaved forests, the Ailao Mountains