Ensemble SDMs reveal the effect of environmental suitability and nature reserves on conserving Chinese pangolins in Guangdong, China

Abstract

Identifying species distribution patterns and threatened factors is essential for wildlife conservation. For the critically endangered Chinese pangolin, most studies have emphasized negative human interference and ignored the effect of environmental suitability and positive human intervention on altering species distribution patterns. We took Guangdong Province as the research area and obtained census data of the Chinese pangolin. Combined with five types of environmental variables, including climatic, geographical, human, soil and vegetation, we used five algorithms in BIOMOD2 to construct an ensemble species distribution model (SDM) of the Chinese pangolin. The importance and response curves of environmental variables were also obtained. We used the cutoff as a threshold to classify habitat or non-habitat, calculated the habitat coverage of established nature reserves by overlay analysis, and visualized the conservation gaps. The results indicate that the potential distribution range of the Chinese pangolin is wide, fragmented and determined by multiple factors. The average annual temperature (highly correlated with elevation) and the highest temperature in the warmest month were the main influencing factors (contribution rate > 10 %), and the distance from nature reserves and human footprint index were secondary factors (contribution rate > 5 %). The established nature reserve network covers approximately 23 % of the potential habitat of the Chinese pangolin. The proposed Nanling National Park seems incapable of protecting the widely distributed Chinese pangolins. In eastern and northern Guangdong, including Meizhou, Heyuan, Shaoguan and Huizhou and Qingyuan cities, there is still a large area of habitat suitable for the Chinese pangolin that is not well protected. We suggest further expanding the current nature reserve network to absorb suitable habitats of Chinese pangolins from adjacent areas and optimizing the spatial arrangement to improve conservation efficiency.