Abiotic factors predict taxonomic composition and genetic admixture in populations of hybridizing white oak species (Quercus sect. Quercus) on regional scale

Abstract Knowing which drivers affect the spatial distribution of hybridizing species and their admixed individuals on local or regional scale can leverage our understanding about processes that shape taxonomic diversity. Hybridizing white oak ( Quercus sect. ) represent an ideal study system to elucidate environmental factors determine relative abundance admixture levels within forest stands. To elaborate these relationships, we used 58 species-diagnostic single-nucleotide polymorphism (SNP) markers high-resolution topographic soil data identify associated with composition populations in 15 mixed stands Q. petraea pubescens Valais, inner-Alpine valley Switzerland. At individual tree level, generalized linear models (GLMs) explained a relatively small part variation R 2 = 0.32). population GLMs often large 0.54–0.69) indices. Mean sites depended mainly altitude geographic position. Moreover, more within-site found predictors related position, higher was average genetic single trees. Our results show multitude edaphic two heterogeneity promote diversity admixture. Overall, highlights prospects using tailored resources understand predict response changing environments.