Are Food and Habitat Resources Key Factors Determining Bird Species Richness at Broad Landscape-Scale in the Mainland of China?

This work aims to examine the spatial pattern of bird species richness at broad landscape-scale and to determine the key factors correlated to this pattern in the mainland of China. We divided the mainland of China was divided into 241 quadrats, 2° latitude by 2° longitude. The number of bird species occurring in each quadrat was counted based on available records. Plant species richness was also measured and net primary productivity estimated for each quadrat. Climatic data of each quadrat were based on 30-year records from 830 county’s meteorological stations. The results showed that bird species richness was significantly correlated to most factors examined. Factors of food, water and habitat resources such as plant species richness, primary productivity, annual mean precipitation, and longitude were most significantly related to bird richness in China. Other factors such as monthly mean temperature of January, frost-free period, minimum temperature, annual mean temperature, latitude showed somewhat indirect effects on bird species richness, i.e. specifically, they directly influenced plant richness and productivity, which then influenced bird richness. The maximum bird species richness occurs in the south of Yunnan province close to Yarlung Zangbo Grand Canyon probably in response to rich food resources, while the minimum plant species richness was found on Qinghai-Tibetan Plateau where food resources and habitats are limited. Based on our results, we suggest that the protection and development of food and habitat resources should be a priority to conserve bird diversity in China.