Data from: Genetic diversity and ecogeographical niche overlap among hybridizing ox-eye daisies (Leucanthemum, Asteraceae) in the Carpathian Mountains: the impact of anthropogenic disturbances

This study examines the ecogeographical niche overlap and genetic
diversity among three Leucanthemum species in the Carpathian Mountains:
the lowland L. ircutianum (4x), the montane L. rotundifolium (2x), and the
alpine L. gaudinii (2x). Previous research noted hybridization between L.
rotundifolium and L. gaudinii, but our analysis reveals more extensive
hybridization across all three species, with additional potential
hybridization events among the hybrids. Over 600 individuals were
genotyped using SNP analysis, followed by Principal Coordinate Analysis
(PCoA), Neighbor-Net Network, and Structure clustering. These analyses
uncovered distinct genetic groups corresponding to particular taxa and
supported the formation of hybrids. Within species-specific clusters, L.
rotundifolium is divided into western and south-eastern populations, while
L. gaudinii and L. ircutianum demonstrate close genetic relationships. Our
analyses suggest hybridization between all species pairs and the potential
for triple hybrids. Genetic admixture is further supported by
environmental background. Niche overlap analyses reveal substantial
overlap among species, particularly in line with their vertical
distribution. Climate envelope plots indicate a likely increase in
competition due to climate change, leading to a reduction in available
habitat for mountainous species and an intensification of hybridization.
Anthropogenic influences are intensifying these hybridization trends.
Among the studied species, L. gaudinii is most at risk of overwhelming
hybridization, whereas L. ircutianum may experience habitat expansion.
This study provides insights into the intricate ecological and genetic
interrelations of the Carpathian ox-eye daisies, emphasizing the role of
environmental changes and genetic diversity in understanding and
responding to these dynamics.