Abstract
I aim to investigate how within-species trait diversity of dune-building grasses impacts the resilience of coastal dunes. Globally, coastal dune systems are threatened due to a combination of anthropogenic and climate-induced processes, which negatively impacts biodiversity and coastal dynamics. As these important landscapes emerge from feedback interactions between physical processes and plant growth, coastal vulnerability is tightly linked to vegetation characteristics. My recent work demonstrated that trait differences between and within dune-grass species are critically important to dune development. However, we remain unaware of the level of trait variation within dune grass populations, while it is central to predicting ecosystem resilience, as it controls the response of vegetation to environmental change. In fact, current coastal management strategies not only ignore, but eliminate intraspecific diversity, by planting monotypic cultivars, with negative consequences for population and landscape-level resilience. I hypothesize that natural dune grass populations exhibit a high variation in plant trait distributions that increases population fitness in these spatially and temporally fluctuating environments. In contrast, I expect that restored dunes exhibit less variation with negative consequences for population resilience. I propose a multitiered approach to study trait variation within Europe’s dominant dune building species, Ammophila arenaria. First, I will conduct a field survey to measure trait and genetic variation between and within natural and restored dune grass populations. Second, I will test how intraspecific variation affects population response to burial and wind erosion. Finally, I will explore landscape-level implications of trait variation for dune development through simulation models. The proposed research will be first to bridge plant genetics with ecology and geomorphology, to study the importance of trait variation for coastal resilience. I will share my results with coastal managers to develop planting strategies that conserve and restore intraspecific diversity, which are urgently needed to build resilient, future-proof coastal landscapes.
Netherlands