Relationship between plant diversity and environmental factors of typical mid-subtropical karst forests in China

Abstract

In order to gain insight into the species diversity and functional diversity of forest vegetation in karst hills and their relationships with environmental factors. We analyzed the species diversity and functional diversity of deciduous broad-leaved forest, mixed evergreen and deciduous broad-leaved forest, and evergreen broad-leaved forest in karst hills of Guilin through community investigation, determination of functional traits and environmental factors. And in combination with statistical methods such as one-way analysis of variance, multiple comparisons, and redundancy analysis to investigate the impact mechanisms of environmental factors on the species diversity and functional diversity of different vegetation types. The results were as follows: (1) The Patrick richness index was significantly higher in evergreen broad-leaved forest than that in deciduous broad-leaved forest, and mixed evergreen and deciduous broad-leaved forest. The Pielou evenness index of mixed evergreen and deciduous broad-leaved forest was the highest, followed by deciduous broad-leaved forest and the lowest in evergreen broad-leaved forest. (2) The functional richness index of evergreen broad-leaved forest was significantly higher than that of mixed evergreen and deciduous broad-leaved forest and deciduous broad-leaved forest; the functional evenness index was the highest in mixed evergreen and deciduous broad-leaved forest, the second in deciduous broad-leaved forest, and the lowest in evergreen broad-leaved forest. (3) Redundancy analysis combined with Monte Carlo random replacement test results indicated that species diversity of deciduous broad-leaved forest was mainly affected by canopy openness and soil water-soluble calcium. Functional diversity was affected by soil water-soluble calcium and rock exposure rate. Rock exposure rate and soil thickness were the main restricting factors that affect species diversity and functional diversity of mixed evergreen and deciduous broad-leaved forest. In addition, species diversity was significantly affected by soil available nitrogen. The influencing factors of species diversity and functional diversity of evergreen broad-leaved forest were consistent, and they were all significantly affected by rock exposure rate, soil water content and soil thickness. The results of this study reveal the effects of species diversity and functional diversity of different forest vegetations on non-biological environmental changes, expand the understanding of species diversity and functional diversity of karst hills, and provide further reference for biodiversity protection of karst hills.

Keywords

• forest community
• species diversity
• functional diversity
• karst hills
• environmental factors