A adubação do solo e o tamanho de covas afetam o desempenho de espécies implantadas pós-mineração de caulim e cascalho?

Abstract

Mining contributes substantially to the economy at different scales and plays a key role in the development of various sectors in goods and services. On the other hand, the negative impacts caused by this activity are inevitable, as it intensely modifies the landscape, degrades the soil structure and reduces environmental services. The use of native species in forest restoration has been increasingly recognized as an efficient way to restore the function and structure of postmining ecosystems. The objective of this dissertation was to contribute to the practical and theoretical bases of forest restoration in degraded areas in the Amazon. In the first chapter, a study was conducted with the objective of evaluating the indicators of soil quality, survival and initial growth of 6 tropical forest species in kaolin post-mining areas in Ipixuna do Pará - PA. The study sought to answer whether the use of lime in three volumes of holes affected the chemical properties of the soil and the general performance of the plants at 12 months after planting. Our results showed that the soil is intensely degraded, but the application of lime reduced the concentration of toxic Al in the soil. Through PCA, the first two components explained 67.73% of the variance of the 13 functional indicators of soil quality. PC1 was positively correlated with Ca, Mg, K, SB, CTC and V, while H+Al and Al saturation showed negative correlations. There was a direct influence between the application of lime and the volumes of holes in the growth of the studied species, but we did not notice a well-defined trend and behavior for this structural indicator. Despite this, we highlight the high growth rates for the species Inga edulis, Inga cayennensis, Clitoria fairchildiana and Tachigali vulgaris. The survival rate varied between 13% and 100% among species, with Clitoria fairchildiana providing the highest percentages of survival, above 75% for all treatments. In the second chapter, we seek to answer whether the survival and initial growth of 4 leguminous forest species were affected according to different fertilization in two volumes of holes in an area degraded by gravel mining at Jari Celulose Company, Monte Dourado - PA. We used dissolving pulp production residues (i.e. branches, bark and leaves of Eucalyptus spp.), coconut fiber blanket in two holes in the overall performance of the plants 15 months after planting. Our results showed excellent growth rates for the four species evaluated, ranging from 160.75 to 279.26 cm year-1. The periodic annual increment (PAI) in DBH of cellulose residue promoted significant increase of Clitoria fairchildiana, but it did not differ from the other species. Furthermore, survival rates were equal to or greater than 80% for the species Clitoria fairchildiana, Inga edulis and Inga thibaidiana. The species used are recommended for gravel post-mining areas as they easily promote the structuring of the ecosystem. Additionally, the results of this dissertation contribute to the science of forest restoration and suggest adapted species to recompose degrades areas by mining in the Amazon, especially due to the characteristics of rapid growth and restoration of services.