River dike grasslands can reconcile biodiversity and different ecosystem services to provide multifunctionality

Abstract

River dikes are secondary habitats that support species-rich grasslands when maintained by low-intensity mowing or grazing. Besides erosion control and habitat creation, dike grasslands have provided several other ecosystem services (ESs), such as biomass production and recreation. Despite the existence of trade-offs between ESs, the overarching aim of restoration and management on river dikes is to increase its multifunctionality. We believe that multiple land uses can be reconciled with biodiversity conservation. Here, we propose a conceptual framework for assessing grassland multifunctionality, and test its application using river dikes as a model system. We also present some practical implications based on vegetation surveys and manipulative experiments along the Rivers Danube and Inn in S Germany. We identified four main ESs of dike grasslands ranked by importance: erosion control, conservation of habitats, recreation and biomass production. These ESs are closely linked to general biodiversity aspects, such as species richness. Therefore, ESs can be controlled by site preparation, trait-based seeding design and grassland management. As the multifunctionality of dikes becomes more important under climate change, the spatio-temporal variability of the dike vegetation must also be considered. In conclusion, dike grasslands are an interesting model for restoration and nature conservation, since they have high potential to deliver multiple ESs while increasing biodiversity. However, restoration and management of dike grassland would benefit from more cooperation between conservation and river authorities, and by implementing ecological knowledge and using experiments to test new management or restoration approaches.

Keywords

• biodiversity conservation
• ecological restoration
• grassland management
• habitat connectivity
• multifunctional ecosystems
• river embankment