A GIS-based policy support tool to determine national responsibilities and priorities for biodiversity conservation

critically endangered eco-regions on the WWF/US Global 200 List. The assessment of national responsibility and conservation priorities allowed us to perform further analysis and mapping using attribute tables. For example, in our case study we obtained the number of species associ- ated with a “very high” and “high” level of national responsibility for multiple focal species in each focal area. The national responsibility approach, therefore, provides additional policy-rel- evant information by identifying those species for which a country has high to very high responsibility scores within biodiversity hotspots. With this information, decision makers can allocate limited resources to the most urgently needed protection measures, including capac- ity-building [1, 72]. For more in-depth analyses and interpretation, the tool provides the results not only in map form but also in tables containing all input information, calculated areas, and resulting scores (Table 3, S1 and S2 Data). These outputs can provide insight into the discrepancies between the results of the two methodical approaches offered by our tool. These two approaches should be compared and evaluated in further methodological studies focusing on statistical effects and the functional relationship between environmental variability across countries and value distributions. Our own analysis shows that the more advanced PA-A provides more differentiated results than the PC-A because it takes area of overlap into account rather than simply using the num-

ber of overlapping polygons. This leads to differences in weighting, especially when large coun- tries have relatively little overlap with focal and reference areas. The size of a country also plays a role when considering the number of species for which basic responsibility must be assumed. The larger the territory of a country, the greater the probability that it will include significant portions of the range of a species in the corresponding reference area—a species for which the country then bears basic responsibility. The NRA-Tool described here will allow the determination of national responsibility and conservation priorities across large geographic scales and across all species (and habitats) for which distribution data are available. With the NRA-Tool we are able to conduct global analy- ses and to inform global processes, such as IPBES assessments, about national responsibilities of each member state and to make suggestions on conservation priorities for different species. It can also be used to identify information gaps resulting from a lack of monitoring programs that target species for which countries have a “high” to “very high” degree of responsibility [72]. The results provided by the NRA-Tool, which are hierarchical lists, can be used to start capacity-building efforts in less surveyed regions and countries. The results can also be used in the various other ways outlined earlier [1]. With this information, policy and decision makers will be better equipped to assess when and how policy should be adapted, reinforced, or devel-

oped to fulfill the Convention on Biological Diversity’s Aichi targets. The maps and tables pro- duced with the NRA-Tool are visual supports for making decisions about international biodiversity conservation. Supporting information S1 File. NRA-tool user interface. (PDF) S2 File. An example for the calculations of the Polygon Count-Approach and the Polygon Area-Approach. (PDF) S3 File. List of species used in the illustration example. (ZIP) PLOS ONE GIS-based policy support tool to determine national responsibilities for biodiversity conservation PLOS ONE | https://doi.org/10.1371/journal.pone.0243135 December 3, 2020 18 / 23