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The North Sea was once abundantly covered with hard substrates such as oyster beds, coarse peat banks and glacial erratics, providing habitat to a rich community of marine species. Most of these habitats were destroyed by bottom-trawl fisheries over the past century, and today, the seabed hosts a relatively poor species community. Emerging offshore windfarms include the re-introduction of hard substrate by means of scour protection around the foundation of wind turbines. It is assumed that the new habitat will contribute to marine biodiversity, and this study aims to demonstrate that. Video data were collected using a Remotely Operated Vehicle in four wind farms in the southern North Sea. A quantitative assessment was made to determine the effect of scour protection on community structure. The assessment revealed distinct community clusters for geographic location and seabed type. Windfarms closely located to each other had a more similar epibenthic community compared to those further away. The epibenthic community at the rocky armour layer of the scour protection had a different species composition and a higher species abundance than the one at the sandy seabed surrounding it. Species diversity by means of richness, evenness and the Shannon diversity index was not consistently higher or lower for the communities at the different seabed types. This study shows that marine life inhabits scour protection in offshore wind farms and that it is different from the community living at the surrounding seabed. Knowing the potential epibenthic community structure at and around a scour protection supports the development of new wind farms that include components to enhance their ecological value. Herewith, our study contributes to efforts to restore biodiversity in the North Sea.

Species’ life-history traits underlie species–environment relationships. Therefore, analysis of species traits, combined into life-history strategies, can be used to identify key factors shaping the local species composition. This is demonstrated in a case-study on ants in chalk grasslands. We developed four life-history strategies based on traits related to reproduction, development, dispersal and synchronization that are documented in the literature. These theoretical strategies reflect different responses to certain environmental conditions. They can be characterized as generalists (G), poor dispersers (D), species whose distribution is limited to sites with high food availability (F) and species that are restricted to sites with high soil temperatures during nest founding (T). Next, we tested whether the occurrence of these strategies differed between six Dutch chalk grasslands and four reference sites situated in Germany and Belgium. We found significant differences in species numbers between sites for strategies D and T but not for strategies F and G. The differences could be explained by differences in connectivity and microhabitat conditions; species richness of strategy D decreased exponentially with increasing distance to the next nearest chalk grassland, while summer soil temperature strongly affected species richness of strategy T. From these relationships we could successfully identify the most relevant bottlenecks for the occurrence of both of these strategies in Dutch chalk grasslands. Management recommendations resulting from this analysis include adapting the management timing in Dutch chalk grasslands and focussing on counteracting habitat isolation. With this case-study we demonstrate that the life-history strategy approach is a valuable alternative to approaches that try to identify key factors by analysing the variation in environmental parameters. The main advantage of the presented alternative is the focus on mechanistically understanding species responses, allowing a comparison of processes rather than occurrences of single species.

Effectgerichte maatregelen zijn de afgelopen jaren succesvol ingezet tegen de korte termijn effecten van verzuring en vermesting in het droog zandlandschap. De accumulatie van zuur en meststoffen heeft echter ook een effect op lange termijn. Hoe zien deze effecten eruit en hoe kan herstelbeheer worden ingezet? Een eerste vraag is dan: wat is de referentie waarop we het herstelbeheer moeten richten

In this chapter the impact of peatland restoration on greenhouse gas fluxes is discussed based on a literature review. Casestudies are presented covering different peatland types, different regions and different starting conditions.