Plant-pollinator interactions in apple orchards from a production and conservation perspective

Abstract

In an agricultural landscape, production and conservation ideally go hand in hand. In a win-win scenario, conservation measures provide support for biodiversity and crop production, mediated by pollination for example. Hedges and flower strips are conservation measures that support pollinating insects, such as wild bees and hoverflies. They can be beneficial for crop pollination, but also harmful by dragging away pollinators from crops if flowering simultaneously. Here, we studied plant-pollinator interactions from two different perspectives. First we look at the apple-flower/production perspective investigating whether plant-pollinator networks in apple orchards differ with adjacent flower strips and hedges compared to isolated orchards. With help of the Bayes factor, we investigated similarity and conclude that there are no differences between pollination networks with or without adjacent flower strips and hedges. Second, we look at the pollinator/conservation perspective and analyse the impact of hedges and flower strips on pollinators and their interactions with plants before and after the apple bloom in April. We show that apple pollinators use more flower resources in flower strips and hedges across the whole season compared to isolated orchards. In orchards with flower strips and hedges interactions are more constant over time. We conclude that flower strips and hedges are beneficial for conservation of apple pollinators without being harmful for apple flower pollination being crucial for production.