Green infrastructure (GI) is a concept that has, in recent years, become established within nature conservation and is an important part of Sweden’s work within biodiversity and ecosystem services. The Swedish Environmental Protection Agency defines green infrastructure as “an ecologically functional network of habitats and structures, natural areas and landscaped elements that are designed, used and managed in a way that preserves biodiversity and promotes important ecosystem services throughout the landscape”. IMAGINE has focused on how management strategies can strengthen and support the preservation of green infrastructure in the marine environment.
The need to promote an ecosystem-based approach and a landscape perspective in the management of marine ecosystems is primarily expressed in international and EU law. However, in general, the requirements laid down in international law are vaguely formulated. Moreover, the enforcement mechanisms available under EU law are lacking. While EU law provides both sharper obligations and enforcement mechanisms, there is no explicit legal requirement to preserve a marine green infrastructure or to take measure to ensure that the network of protected areas becomes coherent and representative. The Habitats Directive, however, provides strong protection of designated species and habitats through the establishment of Natura 2000 areas and Member States can be obliged to take connectivity measures also outside protected areas, if this is necessary for the conservation of the species and habitats within a Natura 2000-site. The Marine Strategy Framework Directive moreover requires that the programmes of measures specify measures needed to ensure a coherent and representative network of marine protection areas, but there is no clear definition of those concepts. All in all, the directives
provide little guidance on how to include a landscape perspective in practice. National law allows for the protection of green infrastructure, including the establishment of protected areas, however, even in this case there is no requirement to apply an ecosystem approach or a landscape perspective in the decision-making. Environmental quality standards for good ecological status and environmental status, which also applies outside protected areas, are important tools for protecting green infrastructure. However, there is a risk of a lack of application of the standards in relation to activities that are not subject to a permit requirement under the Environmental Code. It is therefore important that the standards are applied to other decisions under the Code, but also under other legislative acts (such as fishery legislation) and that cumulative effects are taken into account.
Spatial planning is one instrument that can be used to enable a holistic approach in management of marine ecosystems, and thus to preserve and restore marine green infrastructure. However, the current regulations for marine spatial planning lack clear guidance towards conservation or restoration of a green infrastructure in Swedish marine waters. Although there is a requirement to apply an ecosystem approach in the national marine planning, there is no definition of an ecosystem approach and no clear guidance on how to develop plans to achieve environmental objectives. While a good environmental status is one of the, potentially conflicting, objectives to be achieved, it is not clearly stated that this is an overarching objective. Unlike the national planning, there is no requirement for an ecosystem approach to be applied in municipal planning. The regional action plans for green infrastructure from the County Administrative Boards could be an important tool to bridge the gap between national and municipal planning and integrating the management of land and terrestrial ecosystems, if they are integrated in the legal system.
Different parts of the process need different approaches. Within IMAGINE we used spatial modelling to map ecosystem components and connectivity. In the light of DPSIR and MOSAIC, we have implemented scenario-based impact analysis, identification and prioritization of core areas and coherent networks, together with analyses of the regional action plans for green infrastructure and municipal planning. We also reviewed the legal governance of green infrastructure, both in general and in the light of our case studies.
Scenario-based impact analysis can be used to show how different decisions and measures effect nature conservation and environmental goals, and can be used to make recommendations on how to prioritize measures in a spatial perspective. Within IMAGINE, we applied scenario-based analysis in three case studies focusing on shore exploitation, trawl fishing and climate change. As an example of potential effects of exploitation, we evaluated the effect on eelgrass habitat of different alternatives for regulating jetty development in the Koster Sea over the next 30 years. We calculated the total area and the proportion of shallow areas with expected disturbance based on different development rates for jetty construction, as well as changed placement of newly added jetties to minimize the impact on eelgrass. The impact of trawling on sea pen habitats was investigated by comparing current conditions with occurrence of sea pens modelled based on data from a less affected reference area, thus demonstrating the possible long-term effect of reduced trawling. The effects of climate change on the marine environment were investigated by applying climate development scenarios from SMHI. The expected temperature increase will most likely lead to lower salinity in the Baltic Sea. As salinity limits the distribution of marine organisms in the Baltic Sea, the occurences of important habitat-forming species such as the blue mussel and bladder-wrack are likely to change as well.
Based on our scenarios, we evaluated the potential and limitations of various legal planning and nature conservation instruments to achieve the goal of preserving and developing a marine green infrastructure. We further suggest how these instruments can be developed and adapted to ensure that knowledge and understanding of marine green infrastructure can be integrated into national, regional, and local decision-making. The results of our case studies show that to assess and integrate cumulative effects of different pressures, geographically defined information on both activities and nature values is needed, as well as legal measures that ensure a landscape perspective in planning, decision-making and management.