Plateau pikas (Ochotona curzoniae) at low densities have no destructive effect on winter pasture in alpine meadows
Wanrong Wei, Jundong He, Qiaoyan Zheng
Abstract
The plateau pika (Ochotona curzoniae) is a common small mammal species present in the alpine meadow ecosystem on the Qinghai-Tibetan Plateau (QTP), and is regarded as a pest in alpine meadows when population density exceeds a certain threshold. However, whether pikas with a low population density have a detrimental effect on alpine meadows in winter pasture is unknown. Vegetation and soil were sampled in eight individual pika patchy home ranges and eight control areas, and we found vegetation and soil properties showed different trends in the pika home ranges. Plateau pika activity significantly increased the below-ground biomass, soil pH and total potassium, but had no significant effect on the plant species richness or diversity, soil moisture, NH4-N, NO3-N, total phosphorus, available phosphorus and soil organic content. However, plateau pika activity reduced some vegetation and soil properties (e.g. vegetation cover, vegetation height, aboveground biomass, graminoids, soil bulk density and available potassium). These results imply that pika activity may improve some soil nutrients but have no destructive effect on winter pasture at a low population density.