Spatiotemporal Variations and Driving Factors of Species Richness in China Based on Satellite-derived Dynamic Habitat Indices

The variation of biodiversity in China has attracted extensive interest with the rapid development these years. Comprehending the past and current patterns of biodiversity in China is of significance for development planning and biodiversity management. Satellite data has proved to be a useful tool to characterize the spatial distributions of species on the basis of the species energy hypothesis and hence support biodiversity conservation. The main objectives of this study, therefore, was to evaluate different proxies for annual species richness in China from Moderate Resolution Imaging Spectroradiometer (MODIS) as input for the Dynamic Habitat Indices (DHIs), and to analyze the trend and triggers of variation in DHI for the period 2003 to 2015. We calculated the DHIs (including DHI_cum, cumulative productivity; DHI_min, minimum productivity; DHI_var, intra-annual variation of productivity) in China at 1-km resolution from vegetation productivity MODIS products (NDVI, EVI, LAI, fPAR and GPP), based on the median of the good observations of all years from the whole MODIS record in both 8- and 16-day composites during the year, and calculated species richness at 10-km resolution from species range maps from the IUCN Red List. The linear relationships between the species richness and different DHIs were evaluated and the best performed DHI was obtained. We further analyzed the long-term trend of the best performed DHI by least squares linear regression analysis and performed partial correlation analysis with annual precipitation, mean temperature and solar radiation, respectively. Generally, we found that all DHI_cum and DHI_min had high explanatory power for estimating species richness (R² > 0.6), and the GPP outperformed other indexes. The trend analysis showed that the most regions resulted in an insignificant change while the significant changes had appeared in several areas, like North China Plain and Inner-Mongolia. Our study revealed the spatiotemporal pattern and variation of species richness in China, and is promising for application in biodiversity conservation and policy making.