# Lithological Inheritance Governs Spontaneous Vegetation Succession on Contaminated Soils and Indirectly Regulates Soil–Plant Uranium Transfer in High-Altitude Mine Wastelands, Southwest China

## TL;DR

This study explores how soil origin affects plant growth and uranium uptake in contaminated mine areas in China.

## Contribution

The study identifies how lithology influences vegetation succession and uranium accumulation in plants for phytoremediation.

## Key findings

- Propylite substrates support higher plant diversity and soil organic matter compared to porphyry and siltstone.
- Potentilla supina and Cynoglossum wallichii are effective uranium accumulators with high bioconcentration factors.
- Soil organic matter and bulk density are key factors influencing plant community structure in contaminated areas.

## Abstract

High-altitude mine wastelands in Southwest China present formidable challenges for ecological rehabilitation due to extreme climatic stressors and multi-element contamination. Ecological restoration is closely related to soil environment. However, the mechanism by which parent material-induced heterogeneity governs spontaneous vegetation succession is still poorly understood. We established 36 plots (216 quadrats) to investigate the soil physical and chemical properties and vegetation restoration of propylite, porphyry and siltstone in the Xifanping Copper Mine, Sichuan Province. Furthermore, fifteen metal/metalloid elements (Au, Ag, Mo, W, Cu, Pb, Zn, Hg, As, U, Se, Cr, Sn, Ti, Total Fe2O3), soil pollution and vegetation structure were evaluated. The study area exhibited severe composite pollution (mean Nemerow integrated pollution index = 8.09), primarily driven by Au, Ag, Mo, W, and Cu. Vegetation surveys identified 34 vascular plant species from 12 families. Propylite-derived substrates supported significantly higher species richness, Shannon–Wiener diversity, and soil organic matter than porphyry and siltstone. Redundancy analysis (RDA) identified soil organic matter (SOM) and bulk density (BD) as dominant environmental filters, with SOM explaining 14.03% of community variance (p < 0.01). Two native pioneers, Potentilla supina and Cynoglossum wallichii, were identified as specialized uranium (U) accumulators with bioconcentration factors of 13.39 and 4.49, respectively. Lithological inheritance dictates early successional trajectories by influencing edaphic structure and nutrient bioavailability. The identified U-accumulating species provide a valuable genetic resource for implementing Assisted Natural Regeneration (ANR) and developing sustainable phytoremediation strategies in contaminated alpine ecosystems.