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Linear landscape elements as ecological corridors for plant species under a changing climate

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Linear landscape elements such as hedgerows and road verges can connect isolated fragments of natural and semi-natural habitats, thereby facilitating the movements of species across fragmented landscapes. This could be particularly important as the need for species to move is predicted to increase substantially with climate change. However, so far, we know little about the efficiency of these linear structures to act as habitats or movement corridors for plant species with limited dispersal capacity and specific habitat requirements. Moreover, we do not know whether linear landscape elements will continue to deliver this function under a changing climate. In this research, we show that hedgerows and road verges across Europe can support diverse plant communities, including also species that are usually associated with large and stable habitats such as oldgrowth forests and species-rich, semi-natural grasslands. Furthermore, these linear structures may also serve as a dispersal route for some, but certainly not all, plant species. Factors such as time and spatiotemporal connectivity played an important role here (i.e. ancient corridors with long-term connection to a source population in a larger habitat patch are generally more effective), but also other habitat-specific features including soil properties, microclimate and management. We conclude that hedgerows and road verges may contribute to species persistence and increase functional connectivity in fragmented agricultural landscapes. Further research is needed to elucidate how climate change will alter plant community dynamics in linear elements and influence their future efficiency as ecological corridors. Finally, we emphasize the importance to integrate efficient strategies for preservation, creation and management of linear landscape elements in policies and management plans, both at national (e.g. agri-environment schemes) and international level (e.g. European Common Agricultural Policy).
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