Pika burrow and zokor mound density and their relationship with grazing management and sheep production in alpine meadow

Abstract

Plateau pikas (Ochotona curzoniae) and plateau zokors (Myospalax baileyi) occur naturally in the alpine meadow of the Qinghai–Tibet Plateau (QTP). Their feeding and burrowing activities affect plant composition and soil properties (e.g., soil carbon accumulation and soil nitrogen cycling), but research to study the complex interactions between small mammals, livestock, and habitat is currently lacking. We conducted a sheep grazing trial to determine the effect of grazing management on pika burrow and zokor mound density, and the relationships between sheep production and pika burrow and zokor mound density. The grazing management approaches were warm‐season rotational grazing at 24 and 48 sheep months (SM)/ha, cold‐season rotational grazing at 24 and 48 SM/ha, seasonal continuous grazing at 24 SM/ha, and whole‐year continuous grazing at 48 SM/ha. The results of this study suggested that warm‐season rotational grazing at low stocking rate did not significantly change both pika and zokor densities. Cold‐season rotational grazing at both high and low stocking rates and seasonal continuous grazing at low stocking rate led to an increase in zokor mound density, but not pika burrow density. Whole‐year continuous grazing at high stocking rate increased both pika and zokor densities. The influence of pika and zokor activities on sheep production was complex and differed between grazing management. Sheep liveweight gain peaked at moderate pika burrow and zokor mound density at low stocking rate under both warm‐ and cold‐season rotational grazing. The threshold values of pika density were about 110 and 70 burrows per hectare in warm and cold seasons, respectively. The threshold value of zokor density was about 400 mounds per hectare in the cold season. In contrast, under high stocking rate regardless of management approach, sheep liveweight gain declined significantly as both pika burrow and zokor mound density increased. This paper provides a theoretical understanding and experimental evidence for sustainable grazing management and restoration of degraded grassland by local herders and policymakers.

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

“…The results of this study showed a density of 5500 pika burrows/ha in degraded alpine shrub meadow, whereas surveys conducted in the western part of the southern Qilian Mountains have shown that the average number of pika burrows in normal grassland is 300–800 burrows/ha (Qin, Sun, et al, 2020; Qin et al, 2019; Yi et al, 2016). In contrast, studies of degraded alpine grassland in the hinterland of QTP found the average number of pika burrows to be 2700–4775 burrows/ha (Liu et al, 2017; Tian et al, 2019; Wang et al, 2020; Wei et al, 2013), and in the degraded grasslands of the eastern QTP, the density of pika burrows can even reach 7066 burrows ha −1 (Zhang et al, 2021), which is close to our results. The density of pika burrows has been proven to be significantly correlated with the coverage of vegetation and bare soil (Tang et al, 2019; Zhang et al, 2021), and it is also a valid indicator to estimate the population size of pika in the plateau.…”

Ecosystem Coupling and Ecosystem Multifunctionality May Evaluate the Plant Succession Induced by Grazing in Alpine Meadow

“…High ecosystem multifunctionality may show a higher sensitivity response to STC, SM, PD, and AGB ( Figure 6B ). Previous studies had used observational data to indicated that ecosystem functions differ in their sensitivity to grazing pressure (Ren et al, 2018 ) and restoration practices (Wang et al, 2020b ). In this case, the lower ecosystem coupling and multifunctionality in Stage 4 induced by grazing may be caused by several mechanisms.…”

Analysis of the Impacts of Environmental Factors on Rat Hole Density in the Northern Slope of the Tienshan Mountains with Satellite Remote Sensing Data

“…However, these considerations may be not significant in NTXJ because the grazing duration on alpine grassland is short, lasting only one to two months, and is often concentrated in summer [50]. However, compared with NTXJ, throughout other alpine meadows, or grassland areas in the world [51][52][53], longer grazing durations may indeed have a more significant impact on the population density of rodents. In addition, in alpine meadows, small rodents such as pika may spend the winter by eating yak feces [54], so the population density and grazing intensity may also show a positive correlation.…”