Survival and growth of tree species after kaolin mining in eastern Amazonia, Brazil: accelerating restoration through physical alteration of Technosol

Abstract

Background and aims

Mining causes severe damage to forest ecosystems, and the restoration of these environments in Amazonia remains a challenge. The first step is restoring the quality of the Technosol for plant establishment. This study evaluated the effects of pit size on the chemical properties of Technosol and the performance of selected tree species.

Methods

Three different pit sizes were tested: Small Pit or Control (CTR), Medium Pit (MP), and Large Pit (LP) in an area degraded by kaolin mining. Four tree species were used for each pit size. After 24 months of planting, the chemical properties of Technosol, survival, periodic annual increment (PAI) for total height (PAI_Ht) and diameter at soil height (PAI_DSH), canopy area (CA), and aboveground biomass (AGB) were evaluated.

Results

The study found no significant differences in the chemical properties of Technosol across pit sizes (CTR, MP and LP). Survival rates were consistently high for all treatments. MP and LP provided the best increases in PAI_Ht of Tapirira guianensis. Average CA values ranged from 0.41 ± 0.19 to 1.82 ± 0.31 m² between species, and LP provided the highest average CA for Terminalia argentea. Furthermore, pit size influenced AGB in Moquilea tomentosa, Terminalia argentea, and Tapirira guianensis.

Conclusion

The restoration technique significantly impacted Technosol properties and species performance, highlighting its role in ecological recovery. These findings offer valuable insights for enhancing forest restoration techniques in tropical regions impacted by mining.