Slow and context-dependent: Responses to grassland extensification across a comprehensive set of ecosystem attributes

Extensification - reducing the intensity of agricultural land-use - is a widely promoted strategy to restore biodiversity and ecosystem functioning in grasslands. However, its effectiveness under varying site-specific conditions remains poorly understood. We conducted a large-scale land-use reduction experiment across 45 grassland sites in three German regions to assess extensification responses in a broad set of above- and belowground indicators. Indicators included abiotic conditions, taxonomic and functional community composition of plants and soil microbes, as well as ecosystem functioning and services. We analysed variation in responses between regions and along a gradient of pre-extensification land-use intensity. A recently developed framework for multi-goal ecosystem restoration was applied to evaluate outcomes relative to predefined targets. After three years of extensification, significant changes were detected in around 40 % of all indicators, although fewer than half of these shifts aligned with restoration targets. Plant-related parameters responded most consistently, likely reflecting the immediate effects of reduced mowing. Belowground parameters, in contrast, remained largely unaffected, consistent with delayed, cascading recovery dynamics. Extensification outcomes varied with context: less productive regions showed stronger progress towards restoration targets, while pre-extensification land-use intensity did not consistently determine comprehensive restoration success. Overall, our findings demonstrate that extensification can promote shifts in ecosystem properties, even within short periods of time. However, some recovery processes - especially belowground - may require longer timescales. These results underscore the importance of site-specific planning and long-term monitoring in grassland restoration. Finally, the results provide an empirical basis for developing predictive scenarios of expected extensification outcomes. • Short-term extensification affected 40 % of indicators across ecosystem attributes. • Not all observed outcomes aligned with predefined restoration targets. • Belowground responses were weak, likely due to time lags and low nutrient depletion. • Extensification outcomes varied with site productivity and land-use history. • Extensification is not universally effective and may require complementary measures.