Effect of landscape diversity on temporal stability of Normalized Difference Vegetation Index across spatial scales

Understanding how landscape diversity (i.e., land-cover heterogeneity) influences ecosystem stability across spatial scales is critical for predicting ecosystem responses to environmental change and for designing effective landscape-level conservation strategies. This study aims to quantify the scale dependence (ranging from 0.0625 km² to 2500 km²) of landscape diversity effects on multiple dimensions of ecosystem temporal stability, resistance, and resilience in response to climatic events using satellite-derived Normalized Difference Vegetation Index (NDVI) time series from 2000 to 2020 across four major vegetation types (meadows, shrubs, wetlands, and coniferous forests) on the Qinghai-Xizang Plateau. We also calculated temporal stability of growing season temperature and precipitation at matching spatial scales. We found that both landscape diversity and temporal stability of NDVI increased with spatial scales, whereas resistance and resilience showed no consistent scale dependence. The effects of landscape diversity on temporal stability of NDVI varied significantly across spatial scales in all four vegetation types. In alpine wetlands and shrubs, higher landscape diversity was associated with lower precipitation stability, which in turn was linked to reduced temporal stability of NDVI; however, this indirect relationship was reversed in meadows. Our findings demonstrate that precipitation stability modulates the effect of landscape diversity on NDVI temporal stability across spatial scales. This work not only extends diversity-stability theory by incorporating scale-dependent mechanisms and climatic mediators, but also provides novel guidance for landscape-scale conservation and ecosystem management under changing environmental conditions.