<![CDATA[Ecological damage in tropical post-gold-mining areas in Kuantan Singingi Regency, Riau Province, Indonesia is a major concern, with very low pH and high lead (Pb) bioavailability. Therefore, this study aimed to investigate the synergistic effect of dolomite and organic amendments on the phytostabilization potential of Ipomoea aquatica and Amaranthus caudatus under contaminated substrates from Benai, Indonesia. A 28-day mesocosm experiment tested the effectiveness of soil conditioners in immobilizing metals and determining plant uptake kinetics. Applying amendments effectively neutralized soil acidity and optimized the cation exchange capacity (15.01-20.84 cmol/kg), providing favorable rhizosphere conditions for soil stabilization. Pb removal efficiency was high in both species, with a maximum efficiency of 53.51% for Ipomoea aquatica and 53.05% for Amaranthus caudatus by Day 21. Kinetic modeling showed that Amaranthus caudatus reached maximum accumulation earlier (Day 7) than Ipomoea aquatica (Day 14). Moreover, a bioconcentration factor of 0.67–0.69 and a Translocation Factor <1.0 indicated that vertical metal transfer was limited due to uptake by root systems. A biological approach to internal toxicity management was observed, as no significant growth dilution effect was identified by Day 28. Ipomoea aquatica and Amaranthus caudatus are considered good phytostabilizers and candidate pioneer species for large-scale reclamation because they can rapidly immobilize metals and restore ecological buffering with dolomite addition.]]>
