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

conflicts to be considered, cost considerations, pre-reservation of sites, and so on. If the given target is too demanding, a compromise between costs and targets may be explored by manipu- lating targets. In this process, the consequences of lowering targets should be carefully consid- ered, especially if the lowered target is suspected to be insufficient for sustainable conservation of biodiversity features. Resolution of the evaluation of local units can also be manipulated to control flexibility and get acceptable solutions. Higher-resolution data with more rank levels lead to a narrower range of variation of sets of sites to achieve targets. This is both an advantage and disadvantage. With higher resolution, full advantage can be taken of detailed data. However, a narrower range of variation of the selection leads to smaller flexibility. Reduction of resolution leads to more ties in the calculation process and can lead to larger variation of the results. An appropri- ate level of resolution may be found through repeated trials. Whether or not to incorporate costs and boundary length can be tested in repeated trials with SecSel. These factors may be considered or ignored. The results with or without their con- sideration will be compared during the interactive involvement process. A posteriori involvement. A posteriori stakeholder involvement is the process that occurs after the tool proposes a protected area. Because of the stochasticity in the selection process, SecSel provides multiple sets of sites as land use alternatives. Stakeholders can compare them

to find an acceptable solution. Stakeholders can assess the validity of the design from various points of views, which are not explicitly incorporated into the site selection by prioritization tools. The processes of selection by SecSel are straightforward. There is a clear reason for the addition of each site: its contribution to the achievement of targets. This clarity is an advantage in the a posteriori stakeholder involvement. The high calculation efficiency of SecSel allows repeated trials of site selection, so that stake- holders can easily go back to the interactive involvement phase if needed. Interactive and a posteriori involvement can be fused. Sharing and sparing are alternative approaches to the compromise of conservation and land utilization [19, 20]. Sharing in this context means sympatric conservation and utilization. Sparing is the allocation of land area to conservation and utilization separately. In SecSel, spar- ing can be explicitly considered. Conflicts among local units about features within sites are assessed before site selection, and the conflict is resolved by discarding the local units with lower priority. Since secsel proposes a different resolution for conflicts for each run, stakehold- ers can choose an acceptable resolution at the stage of a posteriori involvement. Some prioritization tools resolve conflicts among features in different ways. In Zonation, sites suitable for purposes other than conservation are given negative values so that such sites will likely be omitted from protected areas. Marxan with zones [6], a derivative of

Marxan, allocates sites into zones before site selection. The allocation is determined by users of the tool. Different targets are set for different zones. In a zone for conservation of wild animals, for example, targets are the total area of the habitats of focal animals or their population size. If a zone is set for agriculture, the target will be the total area of land suit- able for cultivation. The appropriate balance between features that conserve biodiversity and the benefit obtained from land use depends critically on stakeholders’ interests and values. This depen- dence is also critical to the resolution of conflicts between features of biodiversity. SecSel does not provide a decision about which feature has higher priority globally. It compares the relative priorities of local units for the achievement of targets of individual features. There is no need to compare different features with a common currency. It is advantageous for stakeholders to reach agreement among themselves. 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 17 / 19