A trend toward shorter duration and higher intensity of grassland degradation in Chinese oases

Degradation events have been widely observed in grassland ecosystems, yet how their patterns shift under climate change and human activities remains poorly understood. This is especially important for China’s oasis grasslands, characterised by high ecological vulnerability and strong human pressure. Here, we combine temporal segmentation of spectral trajectories with machine learning to examine the evolution, impacts and potential drivers of China’s oasis grassland degradation events during 1990–2021. We find that degradation events are widespread, affecting 68.16% of oasis grasslands. Short-term events (3–9 years) exhibit significantly higher degradation intensity than long-term events (≥10 years) and continue to expand in area. Legacy effects differ among event types, with long-term events reducing ecosystem stability and short-term events causing larger productivity declines. The expansion of short-term events is associated with warming, wetting, greater climate variability and stronger human pressure. These findings suggest that grassland management should place greater emphasis on short-term, high-intensity degradation events and their legacy effects on productivity. China’s oasis grasslands have experienced widespread degradation affecting 68% of the area, with short-term events causing stronger degradation and greater productivity losses than long-term events, according to temporal segmentation of spectral trajectories and machine learning of 1990-2021 data.