# Assessment of Ecosystem Services across the Land-Sea Interface in Baltic Case Studies
## 3 Results
### Comparison of Ecosystem Service Potential and Flow
Hence, one has to keep in mind that the maximal flow values used in this study should not only be representative for the three case studies, but for the Cfb-climate zone in general. Figure 5: Differences between ecosystem service (ES) potential and flow shown on an aggregated level for provisioning, regulating and maintenance, and cultural ES. Low differences (shown in blue) indicate that the ES potential has largely used, and high differences (shown in red) indicate that there is still potential to increase the use of the ES (development capacity). Habitat-weighted use potentials are indicated for each site for the overall areas (O), and for terrestrial (T) and marine (M) areas separately. 'Nutrient regulation' (RM2) was assessed based on nitrogen cleaning. The spatial distribution of development capacities shows similar patterns at land and sea for the three CSS. Lower development capacities are shown at land, especially for the CSS Curonian Lagoon (RM2-CL T:4). Since the area is not agriculturally used, the Nitrogen surplus is low (15 kg N ha\({}^{-1}\) yr\({}^{-1}\)), resulting in a high flow for nitrogen regulation. In contrast, higher development capacities are shown for RM2 for marine areas, especially for the CCS Greifswald Bay (RM2-GWB M:41) and CCS Curonian Lagoon (RM2-CL M:38), with highest development capacities for vegetated areas of the inner coastal waters. 'Natural heritage' (C3) was assessed based on the extend of protected (Natura 2000) areas. Land and sea were assessed separately, but the same maximal flow value (i.e., 100% protected area) was used for land and sea. The CSS Greifswald Bay has the largest flow for marine areas (95%). This is well reflected in the development capacity map (Figure 6.  
Figure 6: Differences between ecosystem service (ES) potential and flow shown for selected. Low differences (shown in blue) indicate that the ES potential has largely used and high differences (shown in red) indicate that there is still potential to increase the use of the ES (development capacity). Habitat-weighted development capacities are indicated for each site for the overall areas (O), and for terrestrial (T) and marine (M) areas separately. C3-GWB). In contrast, only 14% of the CSS's terrestrial area is protected, which is reflected in a habitat-weighted development capacity of 45 for the terrestrial area. However, areas with very high development capacities (around 60 to 80) are shown for areas covered by forest ecosystem types and salt and inland marshes and peat bogs, which are also included in the list of habitats of special importance (Annex I of the HD). Thus, they are included in the CSS's Natura 2000 sites, and are already fully protected. Thus, when considering habitats separately, their development capacity for the specific habitat should be 0, as the maximal flow for the specific habitat has been reached. We used a simplified approach to derive CSS-specific flow matrices and we multiplied the relative flow values of the CSS (0.14 for GWB) with the values of the Baltic ESP Matrix. This has the effect that habitats with high potentials are more impacted by relative flow values compared to habitats with low potentials. This illustrates the need for separate flow values for different habitats.