Evaluation of ecosystem stability against climate changes via satellite data in the eastern sandy area of northern...

Intensive and frequent climate change events (e.g., droughts or extreme weather) significantly affect vulnerable water-limited ecosystems. Until now, the ecosystem stability against climate changes in regional scale sandy lands remain unclear. In this study, the AutoRegression (ARx) model was combined with time-series Net Primary Productivity (NPP) data to extract stability metrics (e.g., temporal stability, resilience, drought-resistance, and temperature-resistance) to evaluate the stability of the main sandy land regions of Northern China. Strong correlations among ecosystem stability metrics were found in the study area, such as the significant negative correlation between resilience and resistance (r = -0.49, p < 0.01), the strong positive correlation between drought-resistance and temperature-resistance, (r = 0.81, p < 0.01), except for the uncorrelation between resilience and temporal stability. Meanwhile, more unstable regions were found in the western low- or moderate-cover sandy grassland. Due to the differences of factors (e.g. hydrothermal conditions, vegetation species composition, and other disturbances or anthropogenic impacts), the unstable grasslands and barren regions, Otindag and Hulun Buir sandy lands, and slightly desertified area (SL) presented more resilience but less resistance and variance than the forest and cropland, Horqin Sandy Land, and Moderate (M) or Severe desertified areas (S), respectively. Thus, the unstable low-or moderate-cover grassland and SL area should be paid much more attention to meet the challenges of more intense climate extremes in the future.