The article explores the hypothesis that biodiversity acts as spatial insurance for ecosystem functioning in heterogeneous landscapes. The authors use a theoretical metacommunity model to investigate how biodiversity affects ecosystem processes and stability at larger spatial scales. The model incorporates explicit consumer–resource dynamics and dispersal among systems, showing that variation in dispersal rates significantly impacts ecosystem productivity through two mechanisms: spatial averaging by intermediate-type species and functional compensations between species. The spatial insurance effects of species diversity are most pronounced at intermediate dispersal rates, which maximize local diversity. These findings highlight the importance of appropriate levels of connectivity in fragmented landscapes for maintaining ecosystem functioning and stability. The results have significant implications for conservation and management, emphasizing the need to understand spatial processes across ecosystems to predict the effects of landscape changes on biodiversity and ecosystem services.The article explores the hypothesis that biodiversity acts as spatial insurance for ecosystem functioning in heterogeneous landscapes. The authors use a theoretical metacommunity model to investigate how biodiversity affects ecosystem processes and stability at larger spatial scales. The model incorporates explicit consumer–resource dynamics and dispersal among systems, showing that variation in dispersal rates significantly impacts ecosystem productivity through two mechanisms: spatial averaging by intermediate-type species and functional compensations between species. The spatial insurance effects of species diversity are most pronounced at intermediate dispersal rates, which maximize local diversity. These findings highlight the importance of appropriate levels of connectivity in fragmented landscapes for maintaining ecosystem functioning and stability. The results have significant implications for conservation and management, emphasizing the need to understand spatial processes across ecosystems to predict the effects of landscape changes on biodiversity and ecosystem services.