MILJØTEMA-MILJØTEMA

In the Nordsalt project, partners from the Nordic countries (Norway, Sweden, Finland and Denmark) together with Germany have during the project period assessed the nature, diversity, extent and long-term changes of Nordic coastal marsh habitats. They have evaluated their role in climate regulation and assessed their vulnerability and the observed changes in ecological structure and functions under future climate warming scenarios, local environmental pressures and management decisions. NordSalt has also assessed the relationships between plant community structure, biodiversity and carbon cycling to evaluate how the marsh habitats provide climate and coastal protection-related benefits to society i.e., ecosystem services. The project has had particular focus on carbon sequestration (so called Blue Carbon) and net greenhouse gas emissions (CO2 and methane) in these ecosystems. Detailed field studies of marsh carbon pools and sequestration rates in grazed and ungrazed locations has taken place at five case study sites across the range of Nordic coastal marsh habitats, and greenhouse gas flux rates have been seasonally measured at three of the case study sites (Finland, Denmark and Germany). The interactions between marsh plant community biodiversity, soil microbial processes and temperature change for net carbon release and storage have also been tested experimentally in a common garden experiment at the University of Hamburg. NordSalt has also explored historical changes in the distribution of Nordic coastal marshes and associated changes in community biodiversity related to climatic and local pressures and management practices, including grazing, which dramatically affects the plant community. Moreover, NordSalt has evaluated the governance of Nordic coastal marshes as nature-based solutions (NbS) in a local, 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 have been evaluated and discussed with relevant policy, management and local stakeholders across all case areas. In total, we facilitated 8 stakeholder driven participatory workshops in the case areas with different stakeholder groups, which allowed us to co-develop future scenarios with these around protection and sustainable use of coastal marsh landscapes. In 2023, presented the results of these workshops, and calibrated and validated these by holding iterative workshops with the stakeholders in separate case based online workshops, updating them on the results of the first workshops and asking for feedback and possible changes given changing contextual settings. In 2024 NordSalt published a policy brief about sustainable management practices under current and future climate settings based both on these results and those of the two published articles on both workshops (published in 2023) and the survey of 5000 respondents across all case areas (published in 2024). Finally, as part of the work in Nordsalt on communication and dissemination, partners have participated as observers at the Convention of Biological Diversity (CBD) and its 15th Conference of Parties (COP15) in Montreal, Canada. Our role in the negotiations was to consider the maturity of blue carbon and carbon credit relative to these salt marshes in Nordic regions. The Kunming-Montreal Global Biodiversity Framework, which was the result of these negotiations, included several targets of relevance to Nordic salt marshes. The most specific is that of 30% protection of all land and sea areas globally, as well as a zero vision for area use in planning in municipalities. During 2023, this was followed up by nations, who will send in their national goals in a standardized format by fall 2024 in preparation for COP16. A goal of NordSalt would be for salt marshes to be included in the national goals of respective member states of the project.

NordSalt developed a generic toolbox benefiting from the combination of a multi-actor approach with qualitative and quantitative instruments and contributed to synergistic policy guidelines and management road maps, and new insights into underlying ecological processes supporting ecosystem services (ES). We contributed to the improved quality of information about the extent and historical changes of Nordic salt marhses, and synthesized the results with stakeholders to assess the feasibility of managing Nordic coastal marshes as NbS in regards to climate mitigation. NordSalt through its work also contributed to general communication about the importance of marshes for biodiversity protection and mitigation and adaptatoin to climate change through continous communication in popular science channels, interviews, and participation in global governance areanas, informing about these ecosystems in Norway. The knowledge generated in the NordSalt project can be used in the EU Adaptation Strategy, WFD, Habitats Directive, Marine Directive and contribute towards the achievement of SDG 13 and 17 by providing information about the role of Nordic coastal marshes for climate change mitigation and as NbS.

Globally salt marshes store over 50% of the coastal carbon (termed “blue carbon”, BC) and are responsible for 25-40% of the global oceanic carbon storage. Remarkably we know very little about BC storage, greenhouse gas (GHG) emissions, habitat and biodiversity loss and ecosystem services in Nordic salt marshes under a changing climate. In NordSalt we will assess (1) changes in Nordic salt marsh habitat distribution, plant community biodiversity, (2) blue carbon (BC) sequestration, GHG emissions and coastal protection as ecosystem services as a function of plant community structure in relation to climate change and local anthropogenic and management pressures. We will combine results from regional and national analyses, case study site measurements and assessments, a long-term mesocosm warming experiment and to assess the current role of these habitats in climate related carbon dynamics as well as their vulnerability to climate change impacts. Most importantly, we will co-produce this knowledge in collaboration with stakeholders that are engaged throughout the project period – and enable the knowledge to be used post-project completion. In collaboration with practitioners and other stakeholders, we will assess the feasibility of and propose management practices for NordSalt habitats as Nature-based solutions (NbS) for climate change mitigation at different levels of governance. We will collaborate with and enable stakeholders to implement our findings into national, regional, European and global climate and habitat policy. Multi-Actor Labs will use qualitative and quantitative tools to support the co-creation exchanges between scientific experts, stakeholders, business entrepreneurs, sector- and administrative representatives. The consortium’s collective expertise, 100+ aggregate years in coastal ecology, biodiversity, climate change mitigation, dissemination and the science-policy-industry interface - providing a good platform for achieving these goals.