Abstract
To halt worldwide biodiversity losses, conservation and restoration measures are taken across the globe. These measures will become increasingly important for the maintenance of biodiversity as increasing human population pressures, land use change and climate change further affect natural ecosystems. To maximize success of conservation and restoration efforts, it is crucial to understand the mechanisms that generate biodiversity. In plants, which are sessile organisms, local and regional biodiversity are determined by the spatial distribution patterns of species. Contrasting theories exist on the mechanisms that generate species distribution patterns. Great theoretical importance is attributed to seed dispersal and especially long-distance dispersal. However, local environmental conditions (niche availability) also have been found to play an important role. Hence, the relative importance of seed dispersal for the generation of species distribution patterns and biodiversity remains a matter of debate. This research project aims to quantify the importance of seed dispersal for the creation of plant species distribution patterns and biodiversity at local and regional (landscape) scales. I will investigate this in newly restored riparian wetlands, where the top-soil layer has been removed. This provides an ideal starting point for measuring natural developments. I will monitor these by mapping spatial environmental variation, species distributions, seed bank and seed deposition patterns in unprecedented detail using high-resolution GPS. To identify the mechanisms that drive pattern formation I will further investigate the interaction between environmental variation, vegetation pattern development and seed deposition. I will do this using a unique combination of seed trapping, seed release experiments in the field and in flumes and mechanistic modelling of seed dispersal by wind and water in heterogeneous environments. This integrated approach of field data collection, experiments and spatial mechanistic modelling will increase our fundamental understanding of biodiversity development and generate knowledge that can be applied directly in restoration ecology.