Integrating genetics and suitability modelling to bolster climate change adaptation planning in Patagonian Nothofagus forests

MARCHELLI, P.; THOMAS, E.; AZPILICUETA, M. M.; VAN ZONNEVELD, M.; GALLO, L.

TREE GENETICS & GENOMES

SPRINGER HEIDELBERG

Año: 2017 vol. 13

1614-2942

Abstract We investigated the impact of past changes in habitatsuitability on the current patterns of genetic diversity oftwo southern beeches (Nothofagus nervosa and Nothofagusobliqua) in their eastern fragmented range in PatagonianArgentina, and model likely future threats to their populationgenetic structure. Our goal was to develop a spatially-explicitstrategy for guiding conservation and management interventionsin light of climate change. We combined suitabilitymodelling under current, past (Last Glacial Maximum~ 21,000 BP), and future (2050s) climatic conditions with geneticcharacterization data based on chloroplast DNA, isozymes,and microsatellites.We show the complementary usefulnessof the distribution of chloroplast haplotypes and locallycommon allelic richness calculated from microsatellite datafor identifying the locations of putative glacial refugia. Ourfindings suggest that contemporary hotspots of genetic diversitycorrespond to convergence zones of different expansionroutes, most likely as a consequence of admixture processes.Future suitability predictions suggest that climate changemight differentially affect both species. All genetically mostdiverse populations of N. nervosa and several of N. obliquaare located in areas that may be most severely impacted byclimate change, calling for forward-looking conservation interventions.We propose a practical spatially- explicit strategyto target conservation interventions distinguishing prioritypopulations for (1) in situ conservation (hotspots of geneticdiversity likely to remain suitable under climate change), (2)ex situ conservation in areas where high genetic diversityoverlaps with high likelihood of drastic climate change, (3)vulnerable populations (areas expected to be negatively affectedby climate change), and (4) potential expansion areas underclimate change.