Response of Plant Phylogenetic Structure to Plateau Pika (Ochotona curzoniae) Disturbance on Alpine Meadow of Qinghai‐Tibetan Plateau

Abstract

Plant community construction is influenced by bottom‐up processes, such as environmental factors, and top‐down processes, such as herbivore disturbances. With climate change and overgrazing, the stability of plant community structure and function decreases, and more land at risk of degradation. However, the response of the plant community to interference from native herbivores under similar environmental conditions remains unclear. Plateau pika (Ochotona curzoniae) is an important small rodent inhabiting the alpine meadow of the Qinghai‐Tibetan Plateau, and its disturbance may accelerate the degradation of grassland ecosystems when its population experiences a burst. In this study, we investigated the plant communities, collected and analyzed the soil samples, to explore the effects of plateau pikas' disturbance intensity on species composition and phylogenetic structure of plant communities on the alpine meadow. We utilized the generalized additive model and structural equation model to explain and predict the response of plant phylogenetic structure and species competition to the disturbance of plateau pikas. Our results indicated that plateau pika disturbance altered the dominance of plant groups, increased species substitution, and facilitated coexistence among different species, and it affected deterministic processes, reduced interspecific competition intensity, and promoted the dispersion of phylogenetic structures. These findings suggested that plateau pika, as a small native herbivore, plays a significant role in fostering multi‐species plant communities. Therefore, it is essential to manage plateau pika disturbance intensity to maintain the stability of alpine meadow plant communities, as well as to influence the long‐term succession of grassland ecosystems. This study provides some new evidence for exploring the effects of native small herbivores on the changes in grassland plant communities.