Attributes of stand-age-dependent forest determine technosol fertility of Atlantic forest re-growing on mining tailings in Mariana, Brazil

Abstract

Understanding how soil fertility changes due to environmental conditions and stand-age-dependent forest attributes is important for local-scale forest restoration. We evaluated the effects of stand-age-dependent forest attributes (plant community composition and litter stock) on soil and technosol fertility across two second-growth Atlantic forests (SGF) after the deposition of mining tailings in Mariana, southeastern Brazil. We hypothesized that technosol fertility in the SGF tailings is positively affected by plant community composition variability, stand age, and litter stock. We used total exchangeable bases and organic matter as fertility indicators for technosol and soil, and species composition and litter stock as stand-age-dependent forest attributes. Our results showed significant differences in the stand-age-dependent forest attributes and soil chemical properties between the two forest patches (SGF tailing and SGF non-tailing) evaluated. Thus, there was a marked gradient of litter storage and fertility between soil and technosol that can be important forest recovery indicators for the affected plant communities. Furthermore, according to the tested models, we corroborated the hypothesis that technosol fertility is positively affected by stand age, plant community composition variability, and litter stock, which may contribute considerably to forest recovery on tailings. Our results demonstrate that the fertility predictors analyzed to explain the forest recovery on tailings can also be considered as ecological indicators for assessing forest restoration in areas impacted by mining tailings in Mariana.

Keywords

Ecological indicators / Forest recovery / Litter stock / Nutrient recovery / Technosol