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.

79 40 INRA, UR 1115, Plantes et Systèmes de culture horticoles, ABSTRACT 138

1. The land-sharing versus land-sparing debate recently stagnated, lacking an integrating perspective in agricultural landscapes as well as consideration of ecosystem services. Here, we argue that land-sharing (i.e. wildlife-friendly farming systems) and land-sparing (i.e. separation of high-yielding agriculture and natural habitats) are not mutually exclusive, as both are needed to balance management needs for the multifunctionality of agricultural landscapes.2. Land-sharing promotes ecosystem services in agricultural settings, thereby allowing for environmentally friendly production. Land set aside in protected areas by land-sparing is crucial for conservation of those species that are incompatible with agriculture.3. Importantly, as species move throughout the landscape and exploit different habitats, increased connectivity between environmentally friendly managed and protected areas is needed to (a) promote spillover of ecosystem service providers from land-sharing/-sparing measures to agricultural production and rescue service-providing species from extinction in hostile areas, (b) to facilitate immigration and counteract possible extinctions in spared habitats and (c) to conserve response diversity of species communities for ensuring resilience of ecosystem services in changing environments. 4. In conclusion, the successful management of multifunctional landscapes requires the combination of context-specific land-sharing and land-sparing measures within spatially well-connected landscape mosaics, resulting in land-sharing/sparing connectivity landscapes. K E Y W O R D S agriculture, landscape design, landscape management, land-sharing, land-sparing, multifunctionality, sustainability | 263 People and Nature GRASS et Al.