Abstract:
Spatial distribution patterns of species diversity and its relationship with environmental factors have been one of core issues in ecology, conservation biology and biogeography. Although climate, topography and human activity factors have been considered as key factors in determining the spatial distribution patterns of species diversity, little is known about their relative roles in affecting the spatial distribution pattern of biodiversity. In this study, combined with the species richness data, climatic data, topographic data as well as human activity data, we investigated the relative importance of climatic variables, topographic variables and human activity variables on the richness of Chinese Theaceae species by using model comparison and variation partitioning. The results showed that: (1) We observed high spatial variation in richness of Chinese Theaceae species. The number of species in all 50×50 km grids ranged from 1 to 88, with an average value of 14.425±13.755; (2) The model including all the climatic, topographic and human activity variables performed significantly better than all other models; (3) In the optimal model, species richness was significantly positively correlated with annual mean temperature (
P < 0.001), significantly negatively correlated with isothermality (
P < 0.05), precipitation seasonality (
P < 0.001), and proportion of cropland (
P < 0.01), and significantly convexly correlated with temperature annual range (
P < 0.01), annual precipitation (
P < 0.001), and elevation range (
P < 0.001); (4) Climatic variables, topographic variables and human activity variables explained 67.86%, 21.50% and 10.64% of variation in species richness, respectively, which indicated that the richness of Chinese Theaceae species was predominantly determined by climatic factors. Therefore, implementing effective protection and management strategies to mitigate the negative effects of climate change and human activities is the key to realize the scientific protection of Chinese Theaceae species.