Multi-scale planning helps resolve global conservation needs with regional priorities

Published in bioRxiv (and in review), 2021.

Rinnan DS, Sica Y, Ranipeta A, Wilshire J, Jetz W. "Multi-scale planning helps resolve global conservation needs with regional priorities." bioRxiv. https://doi.org/10.1101/2020.02.05.936047
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Abstract:

Area-based conservation through reserves or other measures is vital for preserving biodiversity and its functions for future generations, but its effective implementation suffers from a lack of both spatial detail necessary for management practices6 and transparency around national responsibilities that might underpin cross-national support mechanisms. Here we implement a conservation prioritization framework that accounts for spatial data limitations yet offers actionable guidance at a 1km resolution. Our multi-scale linear optimization approach delineates globally the areas required to meet area-based conservation targets for all ~32 000 described terrestrial vertebrate species, while offering flexibility in decision management to meet different local conservation objectives. Roughly 30.4% of land is sufficient to meet conservation targets for all species, of which 60.1% is either already protected or has minimal human modification. However, the remaining 39.9% of human-modified areas need to be managed or restored in some form to ensure the long-term survival for over half of species. This burden of area-based conservation is distributed very unevenly among countries, and, without a process that explicitly addresses geopolitical inequity, meeting species conservation targets would require disproportionately large commitments from poorer countries (i.e., lower GNI). Our analysis provides baseline information for a potential intergovernmental and stakeholder contribution mechanism in service of a globally shared goal of sustaining biodiversity. Future updates and extensions to this global priority map have the potential to guide local and national advocacy and actions with a data-driven approach to support global conservation outcomes.

Conservation priorities for terrestrial vertebrates (~32 000 species) and their supporting evidence and potential action at local scale.
Fig. 1: Conservation priorities for terrestrial vertebrates (~32 000 species) and their supporting evidence and potential action at local scale. In (A) conservation priority areas are colored by the percentile rank of total network-size endemism, i.e., the proportion of the protected range of a species that is found in each planning unit (summed across all species). Displayed PU size reflects the proportion of land needed within each PU as determined by optimization. Dark grey regions indicate terrestrial PUs not overlapping with ranges of any study species. (B)-(D) illustrate the cross-scale planning implications for the zebra duiker (Cephalophus zebra), a threatened West Africa mammal species (see inset in A). (B) shows the Expert Range (ER) and habitat-suitable range (HSR) across PUs, with ~15% of each area currently conserved. (C) additionally displays the all-vertebrate priorities and ranks as identified in (A) that support fine-scale decision-making to address both this species and vertebrates at large. (D) Total amount of zebra duiker habitat protected, prioritizing areas of higher priority rank first. Conservation target of 16% of gridded range map area is met almost immediately; the target of 48% of habitat suitable range requires all areas of >86 percentile rank. Total area protected amounts to 40% of expert range and 56-60% of HSR, depending on choice of within-PU locations.