The main factors affecting the species richness of Theaceae plants in China
Spatial distribution patterns of species diversity and its relationship with environmental factors have always been the core issues in ecology,conservation biology and biogeography.Although climate,topography and human activity factors are 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,the relative importance of climatic variables,topographic variables and human activity variables on Theaceae species richness in China were investigated by using model comparison and variation partitioning.The results showed that:(1)The species richness of Chinese Theaceae species was quite different in spatial distribution,and the number of species in all 50×50 km grids ranged from 1 to 88,with an average value of 14.425±13.756.(2)The goodness of fit of the model including all the climatic,topographic and human activity variables was better than 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)The relative contribution rates of climatic variables,topographic variables and human activity variables to Theaceae species richness in China were 67.86%,21.50%and 10.64%respectively,which indicated that climatic factors played a decisive role in affecting the species richness of Chinese Theaceae species.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 Theaceae species richness in China.
万方数据
维普
