On 6 June at 10:15 Lena Neuenkamp will defend her doctoral thesis "The dynamics of plant and arbuscular mycorrhizal fungal communities in grasslands under changing land use".

Supervisor:
Professor Martin Zobel (TÜ ÖMI)

Opponent:
Professor Catherine Gehring (Northern Arizona University, USA)

Summary:
Human activities have modified about two thirds of all terrestrial ecosystems. European semi-natural grasslands are among the most diverse ecosystems globally; at the same time, they are among the ecosystems most affected by human activities. Such grasslands develop under extensive land use practices – notably grazing and mowing – and land use change can dramatically decrease the extent and quality of such habitats, posing a considerable threat to grassland biodiversity. Many restoration efforts have been undertaken to mitigate against habitat loss, but re-establishing grassland specialist plants often challenges restoration practitioners. This may be because many typical grassland plant species have small seeds adapted to dispersal by wind or grazing animals. As such, a lack of grazing animals or dense vegetation around restored grassland patches might hinder seed dispersal between grassland patches, and thus maintenance of vital meta-populations. It is also possible that restoration sites lack certain soil organisms found in intact habitats, and their absence impairs the establishment of plants that rely on them (e.g. symbiotic fungi, such as arbuscular mycorrhizal (AM) fungi). The aim of this doctoral thesis was to assess the relevance of these factors for successful grassland restoration. The results of the thesis confirm the importance of facilitating plant species dispersal between grassland patches by re-opening the vegetation to create dispersal corridors and by re-introducing continuous grazing management, with grazing animals able to move between grassland patches. Moreover, the results suggest that a lack of suitable AM fungi in the soil of severely altered and isolated grassland patches might hamper natural re-establishment of typical grassland vegetation. Coordinated re-introduction of target plant and AM fungal communities could increase restoration succession in such cases.