The species diversity of entomophilous plants and flower-visiting insects is sustained in the field margins of sunflower crops

Abstract

Field margins are key landscape features sustaining biodiversity in farmland mosaics and through that, ecosystem services. However, agricultural intensification has encouraged fencerow removal to enlarge cropping areas, reducing farmland biodiversity and its associated ecosystems services. In the present work, we assess the role of field margins in retaining farmland biodiversity across the sunflower cropping area of Argentina. Flower-visiting insects and entomophilous plants were intensively sampled along the margins of sunflower fields, in eight locations across eastern Argentina. We recorded 149 species of flowering plants and 247 species of flower-visitors. Plants and arthropods were mostly natives. Most of the floral visitors captured provide ecosystem services to agriculture. Our results show that many species of beneficial insects and native plants occur in semi-natural linear features in the intensively managed farmland of Argentina. Field margins may constitute the last refugia of native plant species and their associated fauna in farmland mosaics. Conservation of field margins in Argentine farmland may therefore be essential for preserving biodiversity and associated ecosystem services.