Landscape diversity promotes landscape functioning in North America
Sarah Mayor, Florian Altermatt, Thomas W. Crowther, Iris Hordijk, Simon Landauer, Jacqueline Oehri, Merin Reji Chacko, Michael E. Schaepman, Bernhard Schmid, Pascal A. Niklaus
Abstract
Biodiversity–ecosystem functioning experiments have established generally positive species richness-productivity relationships in plots of single ecosystem types, typically grassland or forest. However, it remains unclear whether these findings apply in real-world landscapes that resemble a heterogeneous mosaic of different ecosystem and plant types that interact through biotic and abiotic processes. Here, we show that landscape-level diversity, measured as number of land-cover types (different ecosystems) per 250×250 m, is positively related to landscape-wide remotely-sensed primary production across all of North America, covering 16 of 18 ecoregions of Earth. At higher landscape diversity, productivity was temporally more stable, and 20-year greening trends were accelerated. These effects occurred independent of local species diversity, suggesting emergent mechanisms at hitherto neglected levels of biological organization. Specifically, mechanisms related to interactions among land-cover types unfold at the scale of entire landscapes, similar to, but not necessarily resulting from, interactions between species within single ecosystems. Landscape-level diversity – the number of different ecosystems in a 250 m by 250 m area – is positively related to landscape-wide primary production across North America, according to remote sensing observations and statistical analyses.