Data from: Distinct niche divergence characterizes the homoploid hybrid speciation of Pinus densata on the Tibetan Plateau

Ecological divergence and selection for novel adaptations to new habitats
have been theoretically proposed to play important roles in promoting
homoploid hybrid speciation (HHS). The successful establishment of Pinus
densata on the Tibetan Plateau is one of the few known examples of HHS. In
this study, we carried out extensive field expeditions to obtain
representative coverage of occurrence sites of P. densata and its two
putative parents. We then applied a series of GIS-based analyses to define
the patterns of environmental variation within and among the three pine
species, to remove potentially confounding effects of spatial
autocorrelation in the environmental data due to allopatric ranges, and to
build species distribution models. All results consistently indicated that
the ecological preferences of P. densata and its parental species have
diverged, and identified candidate ecological factors associated with
habitat-specific adaptation. Projections from niche modelling indicated
that P. densata could extend across a vast range along the parallel valley
systems of the SE Tibetan Plateau. Our findings provide evidence of a
distinct niche shift in P. densata, and support the hypothesis that local
adaptation and geographic isolation help maintain and reinforce
between-species differences and reproductive isolation in the species
complex.