Comparative Effectiveness of Grassland Restoration at Fine Spatial Scales in the Ruoergai Alpine Grassland, China

Grassland degradation threatens ecosystem function and livelihoods, especially in alpine regions where ecosystems are highly sensitive to disturbance. To compare the effectiveness of common restoration measures at fine spatial scales, we examined four household-level practices in the Ruoergai alpine grassland: year-round grazing exclusion (GE), seeding with grazing exclusion (SGE), seasonal grazing rest (GR), and balancing grazing capacity (BG). Using Sentinel-2 remote sensing data, we monitored vegetation dynamics (NDVI, EVI2, and NIRv) and applied a Propensity Score Matching–Difference-in-Differences (PSM–DID) framework, which constructs comparable control areas without any restoration measures and evaluates whether treatment sites experienced greater pre-to-post restoration changes than their matched controls, thereby strengthening causal inference. All four measures produced statistically significant pre-to-post increases in vegetation indices relative to their matched controls, with GE and SGE showing the largest DID-estimated effects. However, these DID-estimated gains did not persist beyond the implementation year, and in some cases (e.g., SGE, BG), the vegetation indices in treated areas fell below those of the controls, indicating limited persistence. GR and BG yielded smaller DID-estimated effects, reflecting the potential influence of socioeconomic incentives and regulatory challenges on restoration outcomes. These findings highlight the need for sustained management and incentive-aligned policies to maintain restoration benefits in alpine grasslands.