Abstract:

Understanding spatial patterns of species diversity is a hot topic in global ecology because of its significance to biodiversity conservation. We investigated spatial patterns of Chinese seed plant species diversity and analyzed the correlation between species richness and climatic factors at a large scale. Floral information was obtained from national and regional records of seed plants, and climatic data were taken from 642 observatory sites across China between 1970 and 2000. We detected large spatial variation in species richness and density. Species density decreased with latitude. The following did not affect the spatial patterns of species richness and species density: area, mean annual temperature, mean annual precipitation, and frost-free days. Spatial patterns of species richness were affected by annual variation in mean annual temperature, mean temperature during the coldest month, spatial variation of mean annual temperature and precipitation. Spatial patterns of species density were principally shaped by annual variation in mean annual temperature, mean temperature during the coldest month, spatial variation of mean annual temperature per unit area and spatial variation of mean annual precipitation per unit area. Linear step-wise regression models indicated that annual variation in mean annual temperature influenced spatial patterns of species richness, while spatial variation in mean annual temperature and the spatial variation in mean annual temperature per unit area fine-tuned them. Our results imply that spatial and seasonal variation in climatic factors can not be overlooked in research on spatial patterns of species diversity at large scales.

Key words: species diversity, climatic factors, seasonal variation, spatial variation, Chinese seed plants