Climate Change Impacts and Biodiversity Interactions in Nordic Salt Marshes

The NordSalt project will assess the extent of and plant community biodiversity in Nordic Salt and coastal marshes and evaluate how these ecosystems provide climate and coastal protection related benefits to society (ecosystem services, ES or Nature’s Contributions to People, NCP). The project has particular focus on carbon sequestration (so called « Blue Carbon ») and net greenhouse gas emissions (CO2 and methane) in these ecosystems. Furthermore, historical changes in the distribution of Nordic coastal marsh habitat types (ranging from salt marshes to salt meadows to reed beds) and associated changes in community biodiversity related to climatic and local pressures, including management practices such as grazing, will be assessed. Detailed studies of marsh carbon pools (live and dead plant C stocks, soils pools) and sequestration rates (estimated from 210Pb profiles) in grazed and ungrazed locations will be conducted at 5 case study sites, one from each participating country, selected across the range of Nordic coastal marsh habitats. Greenhouse gas (GHG) flux rates will be seasonally measured at 3 case study sites (Finland, Denmark and Germany) Also, the interactions between marsh plant community biodiversity and climate (temperature) change for net carbon release and storage will be tested experimentally in a common garden climate warming experiment conducted at the University of Hamburg with soil and plant mesocosms collected from the 5 case study sites. Results from the NordSalt field and experimental work will be compared to those from an ongoing in situ climate warming experiment in the German Wadden Sea site established by one of the consortium partners. The goal of NordSalt is to assess the nature, diversity and extent of Nordic coastal marsh habitats, to evaluate their role in climate regulation (net greenhouse gas emissions and Blue Carbon storage) and to assess their vulnerability and change in ecological structure and functions under future climate warming scenarios, local environmental pressures and management decisions. Finally, the project will also evaluate the potential of Nordic salt marsh and related coastal vegetated ecosystems as nature-based solutions (NbS) in a regional and global context. To provide the best basis for these considerations, a comprehensive range of climate and coastal protection related ecosystem services (ES) of these habitats will be evaluated and discussed with relevant policy, management and local stakeholders.