Strong benefits of hedgerows to bats in three European winegrowing regions

Abstract

Bats provide important ecosystem services as natural predators of, for example, lepidopteran pests. Thus, it is crucial to identify ways to enhance bat populations in agricultural landscapes. It has been shown that high landscape heterogeneity can benefit bat communities in arable fields. However, to date, the relationship between bats and the surrounding landscape within a viticultural matrix has received little attention, despite moths being major pests in viticulture. Here, we investigated how bats respond to different landscape elements in three European regions: Rhineland-Palatinate (Germany), Burgenland (Austria), and Andalusia (Spain). We recorded bat activity using passive acoustic monitoring for four nights in 94 vineyards in total. Additionally, in Germany, we recorded bat activity along transects from hedgerows up to 120 m into the vineyards to describe the change in activity with hedgerow distance. We found that bat activity decreased with distance from the hedgerow, and the strength of the response was guild-specific. Bat species adapted to foraging in the open space decreased their activity by half at a distance of 120 m from the hedgerow into the center of the vineyard, while bats adapted to foraging along vegetation (edge-space bats) and those adapted to feeding within and close to vegetation (narrow-space bats) decreased their mean flight activity by more than 80% at the same distance. Moreover, the presence of hedgerows between vineyards was positively related to a higher bat activity and feeding rate in all three countries, although this effect varied by functional guild and country. For edge-space foraging bats, hedgerows had a positive impact in all three countries, while open-space bats only showed a significant response in Spain. Hedgerows had consistent positive effects on bat activity in vineyards across the three study regions. Our study suggests that hedgerows should be conserved and restored as key elements to support a higher bat activity. This would also benefit other important groups of animals such as bees and birds along with the ecosystem services they provide.