Epigeic arthropod community changes in response to livestock-caused alpine grassland degradation on the eastern Qinghai-Tibetan Plateau

Abstract

As one of the most important ecosystems, grassland ecosystems maintain an abundance of flora and fauna, and provide humans with rich resources. The structure and function of most grassland ecosystems around the world have been significantly affected by human activity. The overgrazing of livestock and their feces has caused grassland degradation and flora and fauna losses. However, we know little about the relationship between grassland degradation, livestock feces and the arthropod community. In this study, we conducted surveys of the epigeic arthropod community in alpine grassland of the Zoige wetlands in eastern Qinghai-Tibetan Plateau, China. We used ANOVA, multiple linear regression and model-averaging to explore how grassland degradation and livestock feces affected epigeic arthropods community. We found that together grassland degradation and season differently affected taxonomic richness, abundance and different feeding groups of the epigeic arthropod community. Because of the influence of temperature on the epigeic arthropod, the taxonomic richness and abundance of epigeic arthropod community fluctuated dramatically among seasons. Epigeic arthropod community diversity had a significant positive correlation with plant height of all species and Compositae percentage cover in most levels of degradation. The amount of sheep feces had a significant negative correlation with taxonomic richness and abundance of the epigeic arthropod community, because overgrazing sheep reduces the availability of resources and the suitability of micro-habitats for epigeic arthropods. Our study found that moderate levels of disturbance can increase the richness and abundance of epigeic arthropod community over a short period of time.

Keywords

• Arthropod
• Degradation
• Grassland
• Season
• Zoige