Horizontal Distribution Characteristics and Environmental Factors of Shrubland Species Diversity in Hainan Island, China

Abstract

Tropical forests play a vital role in preserving world biodiversity and supporting ecological services. Moreover, the spatial distribution of species diversity and its causes are one of the core issues in community ecology. Therefore, the aim of this study was to explore the horizontal distribution characteristics of shrub community diversity in the tropical region of Hainan and reveal the relationship between species diversity and environmental factors under anthropogenic disturbances. Based on a survey of 39 shrubland plots, we evaluated shrub community diversity by calculating Hill number and Pielou evenness index. Regression analysis was employed to determine the horizontal distribution pattern, and Pearson correlation and redundancy analysis were applied to reveal the relationship between species diversity and environmental factors. The results reveal that species richness increased from west to east and the horizontal distribution of shrubland species diversity in Hainan was largely determined by rainfall and edaphic factors and not by topographic factors. Rainfall factors were the most influential. Although there was a significant human disturbance in Hainan shrublands, environmental factors were still influencing the distribution of these shrublands, and there was a lower shrub diversity in areas with poor moisture conditions, which should be studied more. Our results are of great significance to the study of tropical vegetation and regional biodiversity conservation.