Identifying priority areas for national-level conservation to achieve Aichi Target 11: A case study of using terrestrial birds breeding in Japan

Target 11 of the Aichi Biodiversity Targets established in 2010 by the Convention on Biological Diversity aims to conserve at least 17% of terrestrial areas by 2020. Although global-scale conservation planning to achieve this target has already been attempted, conservation effectiveness strongly depends on region-specific natural and social factors, necessitating planning at the national and regional levels. We conducted complementarity analysis to achieve the target with regard to species distributions of 172 terrestrial birds in Japan, using in part the results of niche modeling, and identified candidate protected areas not currently included in existing protected areas. There was a large difference in landscape structure between existing and candidate protected areas due to the spatial bias of the existing protected areas; these areas were characterized by a high proportion of forest areas and low landscape heterogeneity, while candidate protected areas had a low proportion of forest areas and high landscape heterogeneity. As candidate areas were represented by mainly open lands, including agricultural fields, and were mixed to some degree with secondary forests, threatened species preferring agricultural fields or grasslands were well covered by candidate protected areas. Considering the extremely high cost of land in Japan and the infeasibility of strictly limiting human activities, we propose that facilitating the sustainable use of open lands is a promising approach to achieving Aichi Target 11 in Japan.