Today we separate the two most common ways of managing pollination services in crops. One is the use of managed bees, such as honey bees (Apis spp.) and bumble bees (Bombus spp.), usually by saturation of the crop area. The other is through the conservation, management, and even addition, of flower resources and semi-natural vegetation surrounding the crop, to benefit pollinating wild insects and their habitats. Here we argue that we need to integrate these two managements to improve both pollination services and conservation of wild bees.
Over the past century, the agriculture intensification has caused widespread environmental changes and disturbances in ecosystem services, including crop pollination by wild insects. Particularly, the bee population is declining worldwide, leading to concern about on their critical role in human-dependant crop pollination service. Bees visit more than 90% of the leading global crop types, and improve the yield of approximately 75 % of them, including most fruits, seeds and nuts and several high-value commodity crops such as coffee, cocoa, and oilseed rape. This pollination service is estimated at several hundred billion euros per year, and an estimated 5-8% of global crop production would be lost without pollination services. This pollination service can be provided by both wild bees, such as solitary bees, and managed bees, such as honey bees.
Two main strategies have been proposed to counteract the decrease in crop pollination: (1) the management of pollinator species, which is the most traditional approach, and (2) the management of pollinator habitats. Surprisingly, among the practices reviewed in this study, none were designed to improve the interaction between species and habitat management. However, a clear interaction between both approaches seems to exist. For instance, managed pollinator species can affect the surrounding landscape (risk of biological invasion and competition with wild pollinators), and habitat management can provide supplemental wild and diversified pollinators to crops.
The benefit of integrating these two management approaches is that it is then easier to account for the benefits and costs of both approaches. This is lacking in the current system, where either only one management type is considered or the two is not thought to affect each other. For example, the costs of having large populations of honey bees in an area can be competition and spread of diseases to wild pollinators. This can more easy be managed if the two approaches where to be integrated. Moreover, a high pollinator abundance and diversity can benefit crop yield but contribute to benefits beyond crop pollination, for example, pollination services to the surrounding landscape which can be important for wild flowers and berries.
Therefore, we propose a system-based management of crop pollination that considers synergies and trade-offs between species and habitat management and should integrate costs and benefits from the promotion of biotic pollination to crop production. This systemic concept supports the idea of managed pollinators at low density to be complemented by wild species.
One problem to be solved is that while the individual manager experiences the costs, the benefits may be distributed beyond the farm to neighbours who did not change their practices. This makes it necessary to take more of a landscape approach for managing pollination services and their costs and benefits to the farmer and society as a whole. Furthermore, perhaps we should integrate the benefits to the larger society in the compensation to farmers for their pollination management.
These findings are described in the article entitled Towards an integrated species and habitat management of crop pollination, recently published in the journal Current Opinion in Insect Science. This work was conducted by Lucas A Garibaldi, Fabrice Requier, Orianne Rollin, and Georg KS Andersson from the Universidad Nacional de Río Negro and the Consejo Nacional de Investigaciones Científicas y Técnicas.
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