Responses of China’s dry grassland low-growth to temperature- and water-related extremes

Summary Grasslands in arid and semi-arid regions are highly vulnerable to climate change. While extreme climate events (ECEs) affect vegetation, the relative impacts of temperature-related (heat/cold) versus water-related (drought/wetness) extremes remain unclear. Using coincidence analysis and structural equation modeling across China's drylands, we identified distinct spatial responses: extreme heat suppressed temperate grasslands, whereas extreme cold suppressed alpine grasslands. Extreme drought offsets the positive effect of extreme heat on alpine vegetation. These impacts reflect differing sensitivities to ECEs. Greenness (NDVI) and productivity (GPP) responses were generally consistent, except on the southern Tibetan Plateau, where heat extremes affected NDVI-based low-growth extremes while cold extremes impacted GPP-based low-growth extremes. Our findings highlight the divergent pathways of ECE impacts, providing crucial insights for ecosystem management under climate change.