A global synthesis reveals biodiversity-mediated benefits for crop production

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society. [Abstract copyright: Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Agroecological research: conforming — or transforming the dominant agro-food regime?

Agroecology has three practical forms—a scientific discipline, an agricultural practice, and a social movement. Their integration has provided a collective-action mode for contesting the dominant agro-food regime and creating alternatives, especially through a linkage with food sovereignty. At the same time, agroecology has been recently adopted by some actors who also promote conventional agriculture. Agroecology can play different roles —either conforming to the dominant regime, or else helping to transform it—contingent on specific empowerment strategies. Tensions between “conform versus transform” roles can be identified in European agroecological research, especially in three areas: farm-level agroecosystems development; participatory plant breeding; and short food-supply chains remunerating agroecological methods. To play a transformative role, collaborative strategies need to go beyond the linear stereotype whereby scientists “transfer” technology or farmers “apply” scientific research results. To the extent that farmer–scientist alliances co-create and exchange knowledge, such gains can transform the research system