Grasslands in the Sanjiangyuan National Nature Reserve. Melting permafrost has caused sections of the grassland to collapse as it has lost the supporting structure of the frozen ground. Although this is part of a natural process that feeds water into the delicate surface ecology during the summer, the cycle has been intensified as temperatures have risen rapidly. Yang Yong, a geologist who has been studying this region for the past 30 years points out these pockmarked surfaces of the grassland to be a sign of desertification in the early stages. These partially collapsed sections expose soft soil that are then tunnelled by hares and pika,Ã‚ burrowing mammals whose predators have been over-hunted, which in turn exposes more loose soil that gets swept away by the wind.