Positive but variable effects of crop diversification on biodiversity and ecosystem services

Ecological theory suggests that biodiversity has a positive and stabilizing effect on the delivery of ecosystem services. Yet, the impacts of increasing the diversity of cultivated crop species or varieties in agroecosystems are still under scrutiny. The available empirical evidence is scattered in scope, agronomic and geographic contexts, and impacts on ecosystem services may depend on the type of diversification strategy used. This article assembles for the first time a substantial body of empirical evidence on the positive impacts of cultivated biodiversity on agroecosystems.