Recuperação de campos de altitude após atividade minerária

Abstract

The present work was developed with the objective of studying the ecological components responsible for the plant regeneration in the high altitude grasslands in southeastern Brazil. For such, this dissertation is comprised of four articles. Article 1 is structured in the form of an article, consisting of a bibliographic review. The text approaches the studies developed in high altitude grasslands and rupestrian fields, evaluating the advances obtained in the first. Subsequently, information relevant to the propagation and use of species of higher occurrence in high altitude grasslands were evaluated. In Article 2, the feasibility of the propagules of topsoil species was studied. The propagules from different topsoil depths, collected in four samplings, maintained in storage during one year were evaluated. The results showed that the composition of the seed bank is altered in function of the storage period, and that the return of the topsoil to the location to be restored must occur until the fourth month of storage, thus increasing the success of ecologic recovery projects. In Article 3, the germination of four species that occur in high altitude grasslands (Aristida jubata, Tibouchina sellowiana, Vernonantura phosphorica e Baccharis tridentate) were characterized, testing four temperatures. It was verified that the treatments with temperatures between 20 and 30 o C favor germination, while temperatures inferior to 12 o C and superior to 35 o C inhibit the germination process, and can lead to the death of the plant or temporary delay of germination. It is worth noting that local climate changes can favor alterations in the phytosociological composition of field environments. In Article 4, the Aristida jubata field species was studied, observing how its propagation can contribute with success of high altitude grasslands recovery project. The species presented characteristics that indicated high rate of environmental resilience, with important use in the initial phase and posterior control to facilitate the entry of other species to the environment.