Mapping climate adaptation corridors for biodiversity—A regional-scale case study in Central America

elevational gradients, and overlap with Key Biodiversity Areas. High-priority corridors also con- nected larger lowland protected areas to potential high-elevation climate change refugia that were generally larger, more protected, and spanned wider elevational gradients. However, these high- priority corridors were long (502 km on average) and often spanned at least 2 countries. Addition- ally, high-priority corridors were on average only 52% protected, with only 12 high-priority corri- dors fully protected. Therefore, future access to potential high-elevation refugia will likely be difficult for many species, even under the best of current landscape conditions. Our results also indicate that many potential high-elevation refugia in Central America are currently small, fragmented, and poorly protected. Although we designed our corridor priori- tization to identify corridors that generally terminated in larger, more protected, and more topographically heterogeneous end nodes, such locations are currently rare. Median individual end node size and protection in our analysis were just 11 km2 and 4%, respectively. Given the small size of these sites, competition for local resources could limit successful range shifts even among species that can access these areas. Furthermore, the lack of protection of potential high-elevation refugia indicates that these sites could soon be degraded or lost. These results highlight the need to expand the current protected area network and increase conservation

efforts to restore and enhance ecological connectivity among potential high-elevation refugia across Central America. A recent analysis in South America also demonstrated that most potential refugia across the region are currently unprotected [60]. Taken together, these find- ings depict a bleak picture for biodiversity under climate change throughout Latin America if additional steps to expand protected areas, increase their effectiveness for biodiversity out- comes, and ramp up conservation actions for climate change mitigation are not undertaken. Toward implementation of a regional climate adaptation corridor network in Central America Some corridor studies have been previously criticized for being too coarse or conceptual to translate readily to on-the-ground conservation action, providing few tangible, practical Table 2. Ecological characteristics and conservation status of potential climate adaptation corridors and associated end and start nodes by corridor priority index level*. Corridor variables Level Length (km) Elevation range (m) Forest biomass (Mt C) Protection (%) Overlapping protected areas Overlapping KBAs Number of corridors High 12, 169, 1158 1431, 2185, 3942 30, 64, 117 1, 46, 100 1, 9, 28 0, 6, 13 160 Medium 6, 123, 896 1241, 1868, 2975 17, 61, 114 1, 37, 100 1, 4, 25 0, 2, 10 925 Low 17, 194, 659 1323, 1829, 2565 24, 60, 98 1, 38, 87 1, 6, 22 0, 3, 7 1290 End node variables Level Area (km2) Elevation range (m) Protection (%) High 5, 122, 5938 331, 1277, 3184 0, 100, 100 Medium 5, 11, 5938 143, 682, 3184 0, 5, 100

Low 5, 11, 754 232, 607, 1763 0, 63, 100 Start node variables Level Area (km2) Elevation range (m) Protection (%)^ High 6, 122, 7226 2, 31, 607 100, 100, 100 Medium 5, 11, 7226 4, 171, 627 100, 100, 100 Low 5, 11, 4002 6, 137, 627 100, 100, 100 * in columns 2–8, first, second, and third numbers are minimum, median and maximum values, respectively ^ start nodes were selected as protected areas https://doi.org/10.1371/journal.pone.0304756.t002 PLOS ONE Mapping climate adaptation corridors for biodiversity PLOS ONE | https://doi.org/10.1371/journal.pone.0304756 May 31, 2024 12 / 19