Assessment of the vulnerability of alpine grasslands on the Qinghai-Tibetan Plateau.

Meng Li,Jianshuang Wu,Yongtao He,Xianzhou Zhang,Ben Niu

doi:10.7717/peerj.8513

Abstract

Assessing ecosystem vulnerability to climate change is critical for sustainable and adaptive ecosystem management. Alpine grasslands on the Qinghai-Tibetan Plateau are considered to be vulnerable to climate change, yet the ecosystem tends to maintain stability by increasing resilience and decreasing sensitivity. To date, the spatial pattern of grassland vulnerability to climate change and the mechanisms that vegetation applies to mitigate the impacts of climate change on grasslands by altering relevant ecosystem characteristics, especially sensitivity and resilience, remain unknown. In this study, we first assessed the spatial pattern of grassland vulnerability to climate change by integrating exposure, sensitivity, and resilience simultaneously, and then identified its driving forces. The results show that grasslands with high vulnerability were mainly located on the edges of the plateau, whereas alpine grasslands in the hinterlands of the plateau showed a low vulnerability. This spatial pattern of alpine grassland vulnerability was controlled by climatic exposure, and grassland sensitivity and resilience to climate change might also exacerbate or alleviate the degree of vulnerability. Climate change had variable impacts on different grassland types. Desert steppes were more vulnerable to climate change than alpine meadows and alpine steppes because of the high variability in environmental factors and their low ability to recover from perturbations. Our findings also confirm that grazing intensity, a quantitative index of the most important human disturbance on alpine grasslands in this plateau, was significantly correlated with ecosystem vulnerability. Moderate grazing intensity was of benefit for increasing grassland resilience and then subsequently reducing grassland vulnerability. Thus, this study suggests that future assessments of ecosystem vulnerability should not ignore anthropogenic disturbances, which might benefit environmental protection and sustainable management of grasslands on the Qinghai-Tibetan Plateau.

Highlights

Assessment of the vulnerability of ecosystems which focuses on the assessment of the potential effects of perturbations on a specific ecosystem has become a major topic in the field of global change ecology and sustainability research (Urruty, Tailliez-Lefebvre & Huyghe, 2016; Xu et al, 2016)
In terms of the sensitivity index, most of the alpine grasslands were moderately sensitive to climate change (40 < SI < 60), which accounted for 67.43% of grassland pixels (Fig. 2A)
Climate change is affecting the vulnerability of alpine grasslands on the Qinghai-Tibetan Plateau

Summary

Introduction

Assessment of the vulnerability of ecosystems which focuses on the assessment of the potential effects of perturbations on a specific ecosystem has become a major topic in the field of global change ecology and sustainability research (Urruty, Tailliez-Lefebvre & Huyghe, 2016; Xu et al, 2016). Assessment of vulnerability aims to measure the ability of an ecosystem to resist and cope with environmental perturbations (Crossman, Bryan & Summers, 2012). A more effective and accurate vulnerability assessment framework was presented by Intergovernmental Panel on Climate Change (IPCC), which described the vulnerability as a function of ecosystem sensitivity and adaptivity to climate change with a different character, magnitude, and rate (IPCC, 2001). This definition integrates the multiple properties and processes of ecosystems, including sensitivity, resilience, and exposure, into vulnerability assessment (Xu et al, 2016). Exposure refers to the degree of climate disturbance experienced by a species or ecosystem and represents the rate of migration that species need to follow climate change (Loarie et al, 2009)

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Conclusion