SecSel, a new software tool for conservation prioritization that is applicable to ordinal-scale data for multiple biodiversity features

irreplaceability of the site. However, a combination of sites that are frequently selected does not necessarily result in protected areas that efficiently fulfill targets. This is because the sites in the set chosen in a single run complement each other to achieve the goal, and there is no guar- antee that the goal will be achieved if the set is broken apart. Such properties are common to complementarity-based prioritization, and selection frequency results should be interpreted with caution in this regard. Example of site prioritization Case description: An alpine vegetation in northern Japan threatened by climate change The Taisetsu Mountains in northern Japan are the site of the largest national park in the coun- try (Fig 2). Many alpine plant species (365 species) grow in the Taisetsu Mountains, including subspecies and variants as well as 27 Japanese endemic species [10–12]). In addition, alpine vegetations are expected to be particularly vulnerable to climatic changes [13]. Thus, alpine vegetation should be highly prioritized for conservation. National parks in Japan are expected to play roles not only in biodiversity conservation but also in the provision of ecosystem services. Fields of alpine flowers attract visitors and are one of the most important resources for tourism. Evaluation of biodiversity features. We evaluated the value for conservation based on the area of alpine vegetations which are the targets of biodiversity conservation. We classified alpine vegetations into four types—snow meadow, fellfield, wilderness, and shrubs—for pur-

poses of considering conservation of biodiversity based on the detailed classification of vegeta- tion available from the Ministry of the Environment [16]. We used geographic information system (GIS) data of the vegetation map in the format of an ESRI shapefile [16] to calculate the area of each type of alpine vegetation in each grid cell by projecting the map with the Universal Fig 2. Study site. (a) The position of the Taisetsu Mountains and (b) the national park area. The national park area was drawn based on information provided by the Ministry of Land, Infrastructure, Transport and Tourism [14], and the trails were drawn based on information provided by the Ministory of the Environment [15] under a CC BY license with permission. https://doi.org/10.1371/journal.pone.0247737.g002 PLOS ONE SecSel, a new software tool for conservation prioritization applicable to ordinal-scale data PLOS ONE | https://doi.org/10.1371/journal.pone.0247737 July 23, 2021 9 / 19