Facilitation-suppression transitions of plant functional diversity along the density gradient of a native poisonous plant in degraded alpine grasslands

This dataset accompanies the manuscript entitled "Trait-mediated facilitation–suppression dynamics of a native toxic plant in degraded alpine grasslands", submitted to Functional Ecology. The study explores how the density-dependent expansion of Ligularia virgaurea influences plant community diversity, soil properties, and functional trait structure across alpine grasslands on the Qinghai–Tibet Plateau.