Vegetation recovery and recent degradation in different karst landforms of southwest China over the past two decades using GEE satellite archives

Abstract

Over the past two decades, eco-engineering has been recognized as an important restoration approach to promote vegetation regrowth and greenness in a widespread rocky desertification land of southwest China. However, it remains unclear of recovery patterns and dominating drivers in different types of karst landforms. Here we use multi-satellite archives based on Google Earth Engine (GEE) to reveal the rapid greening process although encountered severe drought, especially in Karst Peak-Cluster Depression (+0.0035y−1) and Karst Trough Valley (+0.0035y−1) influenced by subtropical monsoon climate and afforestation endeavor, while degradation happened recently at non-karst areas of west highland in Karst Fault Basin (−0.0043y−1 since 2006) and Karst Plateau (−0.0039y−1 since 2014) influenced by decreasing rainfall. Afforestation project and sloping land conversion program is found to play crucial part in explaining a large part of the greening trend in Peak-Cluster Depression and Trough Valley but not in other landforms, suggesting that geomorphic heterogeneity should be further considered in restoration implementation and vegetation assessment, in conjunction with climate change and anthropogenic factors. Our study provides a helpful perspective for karst conservation priorities of various rocky desertification region ecosystems.