Efeitos da restauração florestal sobre os atributos do solo e da vegetação após a mineração de bauxita em Paragominas, Pará.

Abstract

The present study aimed to evaluate the effect of forest restoration on soil and vegetation attributes in mined areas after bauxite mining in areas on two restoration methods: Induction of Natural Regeneration and Planting of seedlings in areas with two and Seven years under both methods. In order to do so, we evaluated: (i) quantification of the matrices that surround the studied areas, on a landscape scale, in the Natural Regeneration area; (ii) vegetation richness and diversity in three strata: upper, middle and lower and ) Physical and chemical attributes of the soil in the study areas under the methods of planting and natural regeneration. The study was carried out in an area of mining activity belonging to Mineração Paragominas SA, located in the municipality of Paragominas, Southeastern state of Pará. In the areas of natural regeneration, even in a predominantly forested landscape, the low diversity and the high dominance of Regenerating individuals lead to sudden and abrupt disappearance of tree components during the successional transition phase, causing soil exposure to colonization by pioneer or herbaceous species, such as grasses. The natural regeneration system at seven years was highly efficient in recovering important attributes related to surface soil quality. In the upper stratum, planting of seven-year-old seedlings was efficient in the formation of a forest community close to a reference forest in terms of diversity and equability. However, the lack of a criterion in the distribution of seedlings in the field and the weeding operation to control regenerating individuals in the first five years affected not only the formation of a forest physiognomy, but also allowed the occurrence of large areas with exposed soil, resulting in Substrate with serious physical and structural limitations in the seven-year planting system.