Resumo Dominância de espécies exóticas invasoras e compactação de substratos minerados são filtros ecológicos que geralmente restringem o estabelecimento e o crescimento de espécies nativas de plantas em jazidas mineradas. O entendimento dos mecanismos de atuação e a eliminação desses filtros são de grande importância para a restauração ecológica de ecossistemas. Visando melhorar a condição ecológica de uma jazida tratada com lodo de esgoto dominada por Urochloa brizantha (Braquiarão) e com a superfície compactada, dois tratamentos foram aplicados em parcelas experimentais para se analisarem os efeitos da atenuação desses filtros sobre o recrutamento de plantas: uso de herbicida para redução da dominância de U. brizantha e escarificação mecanizada da superfície compactada, aplicados individualmente e combinados. A atenuação da dominância de U. brizanthae a descompactação da superfície minerada fomentaram o recrutamento de 29 espécies de plantas, 66% das quais descritas como espécies exóticas e invasoras do Cerrado. Os tratamentos aplicados individualmente ou combinados resultaram na formação de biocenoses mais ricas em espécies e mais biodiversas em comparação às parcelas usadas como controle. A cobertura de U. brizantha se recuperou até o final do período chuvoso nas parcelas que receberam os dois tratamentos, mas o recrutamento de espécies que permaneceram sobre a cobertura de U. brizantha melhorou a condição ecológica nas parcelas experimentais.

Abstract The dominance of invasive species and the compaction of mine surfaces are ecological filters that usually restrict the establishment and growth of native plant species. The understanding of ecological filter mechanisms aiming to overcome their effects on the ecological succession is crucial for the ecological restoration of ecosystems. In order to evaluate the effects of reducing the intensity of the surface compaction and the grass dominance on the plant recruitment, we set up 24 experimental plots at six repetitions in a mine dominated by Urochloa brizantha. Treatments consisted in control (T1), herbicide application on U. brizantha (T2), mechanized plowing to ameliorate surface compaction (T3), and the combination of T2 and T3 (T4). Results showed that the chemical attenuation of U. brizantha dominance and surface decompaction allowed the recruitment of 29 plant species, 66% of which are invasive species, exotic to the Cerrado biome. However, the treatments T2, T3, and T4 resulted in the formation of richer and more diverse plant communities in comparison to the plots used as control (T1). U. brizantha cover redeveloped after both surface unpacking and herbicide application, but the plant species that recruited on U. brizantha cover in the meantime improved the ecological condition in experimental plots.

Abstract This study has evaluated the richness of Cerrado woody species engaged in ecological restoration in the Brazilian Federal District (BFD). A survey gathered information on plant species traded by local nurseries, species recommended in restoration plans (PRADs), species effectively introduced in areas under restoration, and species present in preserved fragments of Cerrado. Results summed 566 Cerrado woody species from 80 botanical families of which 171 species were traded by local nurseries, 277 were recommended in PRADs, 190 were effectively used in restoration projects, and 434 species were sampled in fragments of native Cerrado. We found low similarity between species composition available in nurseries, recommended in PRADs, used in restoration projects and present in preserved fragments of native Cerrado. Such results indicate a poor connection between steps related to the selection of native woody species that make up initial plant communities on sites under ecological restoration.

ABSTRACT The vegetation cover development is an essential step towards the restoration of the ecosystems. In this work, we applied remote sensing to evaluate the temporal development of vegetation cover on exploited mines revegetated with five approaches: natural regeneration, tree plantation, cultivation of trees + herbs, topsoil replacement + tree plantation, and sewage sludge incorporation into mining substrate. Results showed that the natural regeneration approach would require a secular time to provide satisfactory vegetation cover on the exploited mine. Tree plantation required fifteen years to provide 80% of vegetation cover. The use of topsoil + trees or the incorporation of sewage sludge into mining substrates achieved the fastest development of vegetation cover (2.5-5 years) and the highest percentages of revegetated surface (80-95%). However, the floristic composition of vegetation covers is as important as their development, and some restoration approaches are reported to stimulate weed invasion while others prevent it.