Human activities have opposing effects on distributions of narrow-ranged and widespread plant species in China

Human activities can drive both species' range contractions and expansions. Species' responses to human activities are suggested to be influenced by their geographic range sizes. Here, we test the idea that human impacts cause range declines in small-range species but promote range expansion of common species, using distribution data for 9,701 plants across China to examine the relation of human activities to the degree to which species fill their climatic potential ranges. We found that narrow-ranged and widespread species indeed exhibited opposing responses to human activities, with their range filling decreasing and increasing with human influence, respectively. These findings suggest that human activities have reduced ranges of narrow-ranged species but expanded those of widespread species, causing biotic homogenization across China.