EVALUATION OF THE INITIAL TREE COMMUNITY ESTABBLISHED ON A GRAVEL MINE IN THE BRAZILIAN FEDERAL DISTRICT

Abstract

Mining activities for urbanization purposes have been practiced in the BrazilianFederal District for the last fifty years. Exploitation of sand, clay, stones, calcareous rocks,and gravel deposits resulted in 0.6% of the territory degraded by mining. Deposits explored inthe last ten years have been reclaimed as demanded by local laws.The natural restoration of areas degraded by mining explotation is unpraticable,because the seed-bed and seedlings-bed is very injuried. Also the superficial layers of soil aretaken off, causing loss of microorganism like fungi, which contributes for environmental’squality improvement for the vegetation reestablishment (Vargas & Hungria, 1997).Fortunatelly, environmental laws oblige miners to replace these superficial layers of soil(CREA-DF Cursos, 2004).The recovering of a degradaded area doesn’t necessarily mean restoration. Restorationonly happens when the damage is minimal, for example, a glade opened by the death of a tree(Fonseca et al., 2001). When an area is hardly damaged, the vegetal climax community,resulting from secondary succession, will never be the same as the one standed there before(CREA-DF Cursos, 2004; Fonseca et al., 2001). In the case of areas degraded by mining,human intervention is necessary, because the vegetation has lost its resilience, and is not ableto commence a secondary succession by itself.