Global karst vegetation regime and its response to climate change and human activities

The vegetation in karst regions (KR) is crucial to maintain fragile local ecosystems. Therefore, it is critical to understand the factors that affect their vitality. The objective of this work is to study global KR vegetation dynamics between 1986 and 2015 and the natural and anthropogenic factors that affect it. The results showed a significantly (p < 0.05) positive greening trend (greening and browning trends were estimated to be 31.90% and 14.29%, respectively). The recuperation of KR vegetation was mainly observed at high latitudes and equatorial regions, where there is less human influence. Nevertheless, the growth of vegetation in some middle and low latitudes areas was a consequence of the human intervention. Vegetation degradation in KR was especially observed at middle latitudes due to the harsh environment and human impact. No significant correlation was observed between karst vegetation stability, the variation of annual average temperature and precipitation accumulated. Globally, karst vegetation dynamics depend more on precipitation than in temperature. In some areas, vegetation can recover gradually, even under extreme conditions and without human intervention. In areas with high population density, vegetation recuperation is mainly as a consequence of restoring programs.