Cross-ploidy hybridisation in Alpine woodrushes is associated with ecological additivity and scale-dependent niche divergence

This data archive contains genomic, ecological and morphometric data used to investigate the ecological consequences of cross-ploidy hybridisation in the Alpine woodrush Luzula alpina. Based on extensive sampling (n = 519), we re-assess the proposed hybrid origin of L. alpina and test the null hypothesis of ecological additivity by evaluating whether the hybrid exhibits niche divergence from its progenitors across different spatial resolutions. Genomic and morphometric analyses confirm the hybrid origin of L. alpina, while environmental niche modelling and vegetation data reveal that patterns of niche evolution depend strongly on spatial resolution. Climatic and edaphic variables largely support ecological additivity, whereas fine-scale vegetation surveys detect subtle but significant niche divergence and shifts in associated plant community composition. The archive includes ddRADseq-derived genomic data, plot-level vegetation relevés, and morphometric measurements from herbarium vouchers, along with key input and output files enabling replication of the analyses.