Biotic homogenization can decrease landscape-scale forest multifunctionality

Abstract

Many experiments have shown that local biodiversity loss impairsthe ability of ecosystems to maintain multiple ecosystem functions athigh levels (multifunctionality). In contrast, the role of biodiversityin driving ecosystem multifunctionality at landscape scales remainsunresolved. We used a comprehensive pan-European dataset,including 16 ecosystem functions measured in 209 forest plots acrosssix European countries, and performed simulations to investigatehow local plot-scale richness of tree species (alfa-diversity) and theirturnover between plots (beta-diversity) are related to landscape-scalemultifunctionality. After accounting for variation in environmentalconditions, we found that relationships between alfa-diversity andlandscape-scale multifunctionality varied from positive to negativedepending on the multifunctionality metric used. In contrast, whensignificant, relationships between beta-diversity and landscape-scalemultifunctionality were always positive, because a high spatial turnoverin species composition was closely related to a high spatialturnover in functions that were supported at high levels. Our findingshave major implications for forest management and indicatethat biotic homogenization can have previously unrecognized andnegative consequences for large-scale ecosystem multifunctionality.