Plateau pikas (Ochotona curzoniae) at low densities have no destructive effect on winter pasture in alpine meadows

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.

Use of DNA metabarcoding of bird pellets in understanding raptor diet on the Qinghai-Tibetan Plateau of China

“…Pikas have been labeled as pests, with a poisoning program to control and eradicate them launched in 1958 (Smith et al 1990;Smith and Foggin 1999). However, more recent research recognizes pikas as important environmental engineers that cause minimal damage to alpine grassland ecosystems (Smith and Foggin 1999;Wei et al 2020). Poisoning them is more likely to have negative impacts (Lai and Smith 2003;Badingqiuying et al 2016).…”

Effects of Plateau Pika Disturbance on the Spatial Heterogeneity of Vegetation in Alpine Meadows

“…Second, more bare soil patches are accompanied by an increase in disturbance intensity of plateau pikas ( Yu et al, 2017 ; Smith et al, 2019 ; Pang et al, 2020 ), which forms more diverse fertilizer islands and provides favorable conditions for the invasion and colonization of pioneer species, resulting in more diversification of species assemblages and an increase in spatial heterogeneity of vegetation. Third, graminoids consumed by plateau pikas become more frequent as the disturbance intensity of plateau pikas increases ( Pang and Guo, 2017 ; Wei et al, 2020 ), which further decreases the dominance degree of dominant graminoids in the plateau pika home range. This leads to reconstruction of plants in the plateau pika home range, forming more unique plant communities at the microhabitat scale ( Scherrer et al, 2019 ), contributing to an increase in the spatial heterogeneity of vegetation in the plateau pika home range ( Yoshihara et al, 2009 ), which implies that the plant productivity in alpine meadows can increase as the disturbance intensity of plateau pikas increase.…”

“…Although 30 disturbed plots, containing different disturbance intensity, is used to identify the general pattern concerning the effect of disturbance intensities on spatial heterogeneity of vegetation, some previous studies have verified that higher disturbance intensity of plateau pikas often results in higher unpalatable plant biomass (mainly consisting of forbs) and less palatable plant biomass ( Zhang et al, 2020 ; Pang et al, 2021 ) and contributes to degradation of alpine meadows ( Liu et al, 2013 ; Wilson and Smith, 2015 ). This implies that the contribution of higher disturbance intensity to degradation of alpine meadows is to deteriorate grazing quality of alpine meadows due to low palatable plant biomass ( Sun et al, 2015 ; Wei et al, 2020 ). Consequently, how to manage plateau pika in alpine meadows is dependent on the operation targets of alpine meadows ( Guo et al, 2012 ).…”

“…Large herbivore grazing has been verified to increase the spatial heterogeneity of vegetation in grasslands ( Adler and Lauenroth, 2000 ; Adler et al, 2001 ; Song et al, 2020 ; Michaels et al, 2021 ). In addition to large herbivores, many kinds of small semi-fossorial herbivores inhabit grasslands ( Bagchi et al, 2006 ; Questad and Foster, 2007 ; Lindtner et al, 2020 ; Wei et al, 2020 ) and these small semi-fossorial herbivores often cause extensive disturbance to grassland vegetation and soil ( Hobbs and Huenneke, 1992 ; Liu et al, 2017 ; Smith et al, 2019 ). They often modify the interspecies relationships among plants through selective feeding behavior and induce several fertilizer islands through redistribution of soil nutrients ( Case et al, 2013 ; Liu et al, 2013 ; Yurkewycz et al, 2014 ; Yu et al, 2017 ).…”

Characterization of the spatial distribution of plateau pika burrows along an alpine grassland degradation gradient on the Qinghai–Tibet Plateau

“…The spatial pattern of pika burrows can provide us with information on the population size and activity patterns of plateau pikas, as well as serve as a basis for determining the degree of grassland degradation (Wei et al, 2019, 2020; Zhao et al, 2019). The traditional survey method is manual field measurements of the burrows, but it still has the shortcomings of being time‐consuming and costly.…”