Crop diversifcation for pollinator conservation

Abstract

Context Intensive agriculture drives insect decline impacting insect-mediated ecosystem services that support production. Crop diversifcation shows promise in increasing crop productivity and enhancing ecosystem services, however, the impact on biodiversity conservation, particularly of pollinators, is unclear. Objectives Here, we synthesize the mechanisms and current evidence base of how increasing the spatial and temporal diversity of crops within and across agricultural felds can beneft pollinator biodiversity. Methods We focus on research in the highly intensifed agricultural regions, in Western Europe and North America, from which we know a lot about pollinator decline, but use inspiration from tropical regions. Results We fnd that higher crop diversity, with sequentially fowering cultivars, intercropping practices, and a larger coverage of fowering crops, for example through integrating the cultivation of forgotten, novel, and woody crops increases fower resource availability throughout the active fight period of pollinators. All practices can increase landscape heterogeneity, which is further enhanced by decreasing feld sizes. As a result, the functional connectivity increases, which improves the fower accessibility within the foraging ranges of pollinators. Conclusions Our review highlights the potential beneft of various crop diversifcation measures for supporting pollinating insects without taking land out of production, as well as the limitations, including that only a subset of pollinator species may benefit. Empirical evidence suggest that diversifcation practices could beneft pollinators, but landscape-wide studies are needed to properly evaluate the true potential of crop diversifcation for pollinator conservation as part of the solution for bending the curve of pollinator decline