In plateaus, land cover replaced climate as the vital environmental factor on the spatial composition of bumblebees with the altitude rising

Abstract

1. Bumblebees show a series of advantages over other pollinating insects in offering pollination services for both the ecosystem and agricultural production, especially in high-altitude areas. With climate warming, their diversity at high altitudes will be threatened. Therefore, more attention should be paid to the management of bumblebee resources at high altitudes to prevent their decline here. Discovering drivers responsible for the spatial variation of biodiversity is a benefit for developing appropriate management.2. Here, based on the bumblebee diversity on three plateau areas with an altitude gradient, the roles of different environmental factors, the climate, land cover, topography, habitat heterogeneity and soil, in the bumblebee composition were assessed by generalised dissimilarity modelling. And the relative importance of variables was evaluated by the impact on the magnitude of total biological change and the per cent change in deviance explained by models.3. According to the results, in the low-altitude area, the climate played a vital role and the most important variable was the climate variable. Then, with the altitude rising, the effect of land cover continually increased. In the medium-altitude area, the effects of different factors were detected to be similar, and the most important variables were a climate variable and a land cover variable. In the high-altitude area, land cover finally replaced the climate as the most important factor, and one land cover variable was assessed as the most important variable. Our study revealed that the relative importance of different environmental factors on the biodiversity of bumblebees can differ as the altitude rises.