Recurrent hybridization mediated range expansion and climate change resilience in two keystone species of boreal forests
P. KARUNARATHNE, Q. ZHOU, M. LASCOUX, P. MILESI
Institute of Population Genetics, Heinrich-Heine University, Düsseldorf, Universitäts Straße 1, 40225 Düsseldorf, Germany

The ongoing global climate change poses a significant threat to biodiversity across various levels, potentially resulting in substantial biodiversity loss. Numerous studies have demonstrated the impact of specific genetic loci on allele distribution within a species' range, correlating with local environmental factors and reflecting instances of local adaptation. However, leveraging this data alone to predict species' adaptation to climate change remains a complex challenge. In this study, we utilized exome capture sequences alongside environmental niche reconstruction to evaluate diverse methodologies for gauging local adaptation and climate resilience in two widely distributed conifers: Norway spruce and Siberian spruce. These species, crucial to the boreal forest ecosystem, share an expansive hybrid zone. Our findings highlight the detectability of local adaptation in conifers through variations in allele frequencies, population-level ecological preferences, and historical niche shifts. Furthermore, through the integration of genetic and ecological data, we unveiled the pivotal role of hybridization in broadening the niche range of these conifers. This process may potentially enhance their ability to adapt to future climate changes. This combined genetic and ecological analysis also pinpointed genetically isolated populations at risk due to ongoing climate changes, emphasizing the urgent need for conservation efforts.