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

Abstract

Climate adaptation corridors are widely recognized as important for promoting biodiversity resilience under climate change. Central America is part of the Mesoamerican biodiversity hotspot, but there have been no regional-scale analyses of potential climate adaptation corridors in Central America. We identified 2375 potential corridors throughout Central America that link lowland protected areas (≤ 500 m) with intact, high-elevation forests (≥ 1500 m) that represent potential climate change refugia. Whereas we found potential corridors in all Central American countries, potential corridors in Panama, Belize, and Honduras were most protected (medians = 64%, 49%, and 47%, respectively) and potential corridors in El Salvador were least protected (median = 10%). We also developed a corridor priority index based on the ecological characteristics and protected status of potential corridors and their associated start and end points. Compared to low- and medium-priority corridors, high-priority corridors (n = 160; top 7% of all corridors) were generally more protected, forested, and distributed across wider elevational gradients and more Key Biodiversity Areas, but also generally linked larger lowland protected areas to target areas that were larger, more protected, and spanned wider elevational gradients. For example, based on median values, high-priority corridors were 9% more protected and overlapped with 2-3 more Key Biodiversity Areas than low- and medium-priority corridors. Although high-elevation targets spanned considerably wider elevational gradients than lowland protected areas (medians = 695 vs. 142 m, respectively) and thus may be more likely to support refugia, they were considerably smaller than lowland protected areas (medians = 11 vs. 50 km2 respectively) and mostly unprotected (median = 4% protection). This initial, regional assessment can help prioritize locations for finer-scale research, conservation, and restoration activities in support of climate adaptation corridors throughout Central America and highlights the need for greater conservation of potential high-elevation refugia.

Fig 1. Study area, lowland protected areas (starting nodes), and highland target areas (end nodes).

Country boundaries are public domain and were obtained from Natural Earth (50m-admin-0-countries-2) before clipping to our study area (https://www.naturalearthdata.com/). Lowland protected areas are polygons ≥ 5 km² and ≤ 500 m elevation from the World Database on Protected Areas [37]. Highland target areas are patches (≥ 5 km²) of upper-montane (≥ 1500 m elevation) contiguous forest with medium or high Forest Landscape Integrity Index values [47].

Fig 2. Comparison of area, elevational range, protection, and mean forest biomass between start and end nodes.

Figure encompasses all start nodes (n = 475) and only the end nodes in which potential climate adaptation corridors terminated (n = 192).

Fig 3. Ecological characteristics and conservation status of potential climate adaptation corridors by country.

Note that our study area only included southeastern Mexico and northwestern Colombia. PA = protected area, KBA = Key Biodiversity Area, BLZ = Belize, COL = Colombia, CRI = Costa Rica, GTM = Guatemala, HND = Honduras, MEX = Mexico, NIC = Nicaragua, PAN = Panama, SLV = El Salvador.

Fig 4. Climate adaptation corridor priority index values.

Country boundaries are public domain and were obtained from Natural Earth (50m-admin-0-countries-2) before clipping to our study area (https://www.naturalearthdata.com/). Lowland protected areas are polygons ≥ 5 km² and ≤ 500 m elevation from the World Database on Protected Areas [37]. Highland target areas are patches (≥ 5 km²) of upper-montane (≥ 1500 m elevation) contiguous forest with medium or high Forest Landscape Integrity Index values [47].

Fig 5. Ecological characteristics and conservation status of potential climate adaptation corridors and end and start nodes.

PA = protected area, KBA = Key Biodiversity Area. ** = significant differences among all group pairs, * = significant differences between high and medium and high and low group pairs only (all based on Dunn’s tests). Log transformations were for visual purposes only.