The complementarity between ecological infrastructure types benefits natural enemies and pollinators in a Mediterranean vineyard agroecosystem

Under the current scenario of biodiversity loss across agroecosystems, the preservation of ecological infrastructures is crucial to maintain ecosystem functions and deliver ecosystem services such as pollination or biological control of pests, which largely determine agricultural productivity and food security. The role that ecological infrastructures such as hedges or strips have in enhancing functionally important groups, including predators, parasitoids and pollinators has been reasonably well investigated in temperate areas. However, it is much less documented in agroecosystems from the Mediterranean basin, even though this area has been identified as a biodiversity hotspot for conservation priorities. In a study developed during 2014 in a traditional vineyard agroecosystem in Northern Spain using a combination of different sampling methods, we analysed beneficial arthropod assemblages across four types of linear ecological infrastructures: woodland hedges, rosaceous hedges, grass strips and flower strips. We investigated the value of these elements as a source of predators, parasitoids and pollinators. We show that ecological infrastructures across this Mediterranean vineyard agroecosystem support functionally important groups and that the abundance, richness and distribution of families of each functional group is determined by features characterising the different types of those infrastructures. Ecological infrastructures with a suitable level of structural diversity constitute an important reservoir of predators. On the other hand, parasitoids and pollinators were limited by the availability of hosts, pollen and nectar resources. Flower strips, less complex infrastructures that offer a high amount of floral resources, benefited communities of both parasitoids and pollinators. Because of the variability in habitat preference found among the different functionally important taxa, we highlight the importance of preserving different types of ecological infrastructures across vineyard agroecosystems to maintain well-structured assemblages of beneficial arthropods and maximise underlying services.