Soil disturbance: Responses of soil carbon to plateau pika bioturbation in alpine grasslands on the Qinghai Tibetan Plateau

Plateau pika (Ochotona curzoniae) is a small, common burrowing herbivore with average 150 g, native to grassland in the Asia, especially to alpine meadows in the Qinghai-Tibetan Plateau. Termed as bioturbator herbivores, this animal can create extensive soil disturbance through digging and burrowing activities. In the process of disturbing the soil, these animals break the soil surface layer, increasing water infiltration, soil moisture, and the capture of organic matter, which leads to change in soil ecological processes. This small burrowing herbivore can shape alpine meadows, even contributes to alpine meadow degradation because its density can range up to 300 individuals per hectare. Consequently, plateau pika is generally considered as a pest in China and extensive control efforts have been conducted to eradicate it. However, several studies have argued that plateau pika is a keystone species for alpine meadow ecosystem. To date, no consensus about the role of plateau pika in alpine meadow ecosystem has emerged among policy makers, professionals and herders, and more studies are needed to examine the impact of plateau pika on soil process. Therefore, take plateau pika as an example, our study focuses on accurately evaluating the service functions of the alpine grassland ecosystem including productivity, soil conservation, and C sequestration under the bioturbation by small burrowing herbivore.