Embedding trait‐based ecology within indigenous knowledge to advance sustainable management of Tibetan rangeland

Abstract

AbstractQuestionsTraditional pastoralists attribute high numbers of plateau pikas (Ochotona curzoniae) to impoverished soils that favor more and better forage for pika, suggesting a bottom‐up control of pika density. Conversely, government policies focus on excessive numbers of this small mammalian herbivore as the primary top‐down cause of degradation in Tibetan rangeland. Despite concerted campaigns to reduce pika abundance in recent decades, the sustainability of Tibetan rangelands remains uncertain.LocationAlpine meadows on the Tibetan Plateau.MethodsWe proposed a conceptual model based on indigenous knowledge that predicted pika numbers from soil condition and plant traits. At three alpine meadow sites lightly grazed by livestock, we tested whether spatial variation in pika burrow density could be explained by changes in the functional composition of the plant community attributable to species turnover and intraspecific trait variation associated with changes in soil fertility.ResultsDue primarily to intraspecific trait variation, changes in the functional composition of the meadow community accounted for 56%–68% of the spatial variation in pika density, changes in the proportion of plant functional groups for 62%–74%, and changes in edaphic conditions for 71%–82%. Greater pika density was associated with a decline in soil phosphorus availability and a lower‐growing vegetation profile enriched in both the quantity and quality of forage preferred by pikas.ConclusionsThese results, which are in accord with indigenous knowledge, suggest that compensating soil phosphorus losses and maintaining a well‐calibrated grazing rotation can better manage pika populations and improve the sustainability of Tibetan rangelands. By combining trait‐based ecology and traditional knowledge, our study provides new insight into both understanding the dynamic complexity of grazing regimes and managing rangeland sustainability.