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

the selection of sites will be more flexible. This flexibility makes it possible to identify a com- pact set of sites that fulfills all the targets for multiple features. Conflict. In SecSel, a conflict may occur in a pair of local units of features within a site. Local units of conflicting features are not conserved or used simultaneously within a site. Con- flicts between incompatible features within sites are resolved before site selection. The local unit that is more critical for achieving the target of the feature has higher priority in resolving the conflict. A local unit of a feature is given lower priority than more critical units of other fea- tures. Because an explicit decision is made about which feature is given priority at a site, it is clear which features within a selected site are to be protected/used in the implementation of conservation design. The details of the decision process are described in section Resolution of conflicts. Input data Compulsory input data. For each feature to be considered, data of evaluation for individ- ual local units are necessary. Furthermore, there should be targets for individual features. Rank levels of local units. Evaluation of local units within each site should be prepared for each feature. For the features to be protected, the evaluation is based on the conservation value. For the features to be used (e.g., ecosystem functions and various land uses), the evalua- tion is based on the quality and/or quantity of the benefit the site would provide.

The evaluation is quantified on an ordinal, interval or ratio scale. Binary data consist of 1 for presence and 0 for absence; three levels may be high, low, and no value; or there may be continuous values that describe the area of concern in an ecosystem or the size of a population. All these metrics meet the requirement of SecSel. There is no limitation on the resolution of the evaluation. On the one hand, the higher the resolution, the more precise the selection of the highest priority local units will be obtained. On the other hand, low resolution enables more flexible selection of local units. Flexibility makes it possible to select a compact set of sites to achieve targets for multiple features. Flexibility also facilitates selection of multiple protected areas that achieve almost the same conservation efficiencies. Targets. For every feature, the number of top local units to be included among the selected sites is specified as a target. For biodiversity features, the target is a conservation requirement. For features to be used, the targets are utilization requirements. If the target of Table 1. Abbreviated explanations for the definitions of terms used in SecSel. Terms Definitions Feature A biodiversity item, land use type, or ecosystem function which are of interest with respect to conservation planning and land-use planning. Site A spatial unit for conservation and land-use planning. Local unit A fragment of any feature within a site. Each local unit is ranked based on its conservation/

utilization value. Local units with relatively high values should be highly ranked. The number of ranks is arbitrary and can differ among features. Top-N included The criterion to define the conservation/utilization target in SecSel. If N local units of a feature that have high ranks are included in a set of sites, and if there are no local units outside the set that have ranks higher than any of the N local units in the set, then the N local units of the feature are defined to be the top-N local units included in the set. Target In SecSel, the targets for individual features are equated to the number of highly ranked units in a protected area. If the target is N for a given feature, the top-N of the units of the feature should be included. Conflict A pair of conflicting features are not conserved or used simultaneously within a site. See the main text for details. https://doi.org/10.1371/journal.pone.0247737.t001 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 5 / 19