Restauração de ecossistemas degradados pela mineração na Amazônia Oriental.

Abstract

Industrial mining contributes significantly to the development of society and concomitantly causes numerous environmental impacts, such as plant suppression. In this sense, the objective ofthis thesis was to determine and evaluate the main methods, ecological indicators and species for implantation in mined ecosystems. In the first chapter, a bibliometric analysis was carried out on the recovery of degraded ecosystems at a global levei, emphasizing the main methods and performance indicators. 700 articles were sampled from 1990 to 2018, with exponential growth in the number ofpublications over time, with the main works being carried out in Brazil, Austrália, the United States and China. Four recovery methods were identified, with planting seedlings and direct seeding being the main ones. Ofthe indicators, the most frequent were the functional ones, with emphasis on the edaphic ones. For the second chapter, a review was made of the economic importance of mining for the state of Pará, as well as its environmental consequences, recovery methods, monitoring indicators and perspectives on the topic. The results showed that mining provides monetary resources to improve society, such as the Financial Compensation for Mineral Exploration (CEFEM). Several gaps must be overcome for the restoration to be successful, such as: a) edaphic issues; b) lack of seeds and seedlings; c) inadequate choice of plant species; d) errors of implantation and distribution of species on the site; e) lack of monitoring and; f) the lack of professional qualifications. The prospects are that in postmining restoration, Unmanned Aerial Vehicles (UAVs) are often used; the use of organic waste; the proper management of topsoil; the more incisive participation of traditional communities; the selection of key species for planting, using arbuscular mycorrhizal fungi and the establishment of a list of indicators with reference values. The third and fourth chapters were held in the municipality of Paragominas, PA. Since, the objective of the third was to select tree forest species for implantation in ecosystems after mineral exploration, for that, five ecosystems with different implantation ages were selected and through the variables survival rate and average increase in diameter and height were selected 30 species suitable for initial planting. In the fourth chapter, three ecosystems in restoration were compared with a reference forest. To meet this expectation, ecological indicators of composition, structure and function were evaluated. Ecosystems in the process ofrestoration differed from the reference forest, mainly for indicators of composition and structure, such as diversity Índices, ecological groups, density of natural regeneration and soil cover by vegetation. In view of this, this thesis demonstrates the growth and the importance on a global and regional scale of the restoration of ecosystems degraded by mining, with the need for more investment in human capital and management for forest restoration.