Global Biodiversity Indicators Reflect the Modeled Impacts of Protected Area Policy Change

Global biodiversity indicators can be used to measure the status and trendsof biodiversity relating to Convention on Biological Diversity (CBD) targets.Whether such indicators can support decision makers by distinguishing amongpolicy options remains poorly evaluated. We tested the ability of two CBDindicators, the Living Planet Index and the Red List Index, to reflect projectedchanges in mammalian populations in sub-Saharan Africa in response to po-tential policies related to CBD targets for protected areas (PAs). We comparedpolicy scenarios to expand the PA network, improve management effective-ness of the existing network, and combinations of the two, against business asusual. Both indicators showed that more effective management would providegreater benefits to biodiversity than expanding PAs alone. The indicatorswere able to communicate outcomes of modeled scenarios in a simplequantitative manner, but behaved differently. This work highlights both theconsiderable potential of indicators in supporting decisions, and the need tounderstand how indicators will respond as biodiversity changes.