Desenvolvimento inicial de espécies florestais nativas em tecnossolo formado por rejeito de mineração de ferro na Bacia do Rio Doce

Abstract

The spill of iron ore tailings, after the dam breaking of Fundão, at the Germano Mining Complex in Mariana-MG, culminated in the destruction and degradation of extensive areas of riparian forest. The mining tailings, added to all sorts of materials that it dragged along until it was deposited on the banks of the rivers, culminated in the formation of an unstable technosol with depth and chemical attributesvariable on the degraded areas. Areas of Permanent Preservation, guaranteed by law, should be restored on the banks of the affected watercourse. The situation is unprecedented in the country and constitutes a great challenge for the science of ecological restoration. The physical and chemical limitations of the formed technosol,effects and consequences on species candidates for use in the restoration actions, need to be evaluated. The present study aimed to evaluate the survival and initial growth of seedlings of five native forest species planted in the technosol of degraded areas of the Mariana-MG region, and to investigate the influence of the chemical correction of this material under controlled conditions. Enterolobium contortisiliquum (Vell.) Morong, Hymenaea courbaril L., Luehea grandiflora Mart. & Zucc., Pterogyne nitens Tul. andSolanum granulosoleprosum Dunal plants responded to thetested treatments, technosol, soil not affected by the tailings and 1: 1 mixture of both, according to their peculiarities. Soil and technosol differ mainly in relation to pH, remaining phosphorus, sulfur, manganese, iron, sodium and texture. All the studied species presented satisfactory initial development in the technosol. Enterolobium contortisiliquum, Luehea grandiflora, Pterogyne nitens and Solanum granulosoleprosum grew more on the technosol than on the soil. The chemical correction positively influenced the growth of the species, with the exception of Hymenaea courbaril, which on the technosol was developed more in the absence of correction. Solanum granulosoleprosum, Enterolobium contortisiliquum, Pterogyne nitens, Luehea grandifloraandHymenaea courbarilare species suitable for use in restoration projects of areas degraded by mining tailings in the Rio Doce Basin.