Data from: Environmental stress shifts community assembly from niche differentiation to trait convergence across Himalayan plant communities.

This dataset contains species-by-plot community data for 482 vegetation relevés sampled across six Himalayan habitat types (salt marshes, wet grasslands, shrublands, steppes, screes, and alpine tundra) in the western Himalaya (Ladakh region).

The dataset includes species identities, plot identifiers, habitat classification, and species relative abundances, together with standardized (z-score transformed) functional trait metrics derived from species-level trait data. These data were used to calculate community-weighted means (CWMs), functional diversity indices, and standardized effect sizes (SES) for individual traits.

SES values were obtained from null-model analyses based on abundance-weighted mean pairwise dissimilarity (MPD), allowing comparison of observed trait dispersion within communities against random expectations drawn from the regional species pool. Negative SES values indicate functional convergence (environmental filtering), positive values indicate functional divergence (niche differentiation), and values close to zero indicate random assembly.

Together, these data form the empirical basis for analyses of community assembly processes, enabling assessment of environmental filtering, niche differentiation, and functional–phylogenetic decoupling across contrasting alpine and arid Himalayan ecosystems.