Natural recovery and restoration in giant panda habitat after the Wenchuan earthquake

Natural disasters affect forest ecosystems in profound and complex ways. Artificial restoration projects have been conducted worldwide to repair disaster damage to forests, but the efficacy of such projects in light of naturally occurring recovery processes is rarely evaluated. To fill such an important knowledge gap, we investigated forest recovery and restoration in the world-renowned Wolong Nature Reserve in Sichuan, China after the catastrophic Wenchuan earthquake (magnitude 8.0) in 2008, which caused considerable damage to the forest and habitat of the endangered giant panda. This was the first multi-year field study to document natural recovery of forests in response to this disaster. Forest sampling conducted in panda habitat over a four-year period after the earthquake revealed that natural recovery was rapid, with vegetation covering roughly 70% of once denuded sites by the fourth sampling year. Vegetation recovery was further improved in sampled artificial restoration sites, which recovered from an average of 30% vegetation cover to 70% in only one year. Factors including soil cover and slope were correlated with successful vegetation recovery. New information learned from the multi-year field data provided a finer scale context for understanding the effects of disasters, a novel contribution considering that the majority of previous work has been conducted at the broader scale using remote sensing. Spatial analysis revealed that restoration sites were mainly distributed in areas of suitable slopes and elevations, but a measurable proportion (30-40%) were located too far from the existing panda distribution area and too close to human settlements. The restoration project has thus far had limited direct effect on giant panda conservation, but has indirect effects on improving forest cover in areas previously affected by human disturbances. This study provides a useful reference for understanding conditions affecting forest recovery, which can inform decision-making surrounding the implementation of forest restoration projects and conservation of endangered species, not only in China but also around the world. (C) 2014 Elsevier B.V. All rights reserved.