PHYTOSOCIOLOGICAL STUDY OF A PLANT COMMUNITY ON IRONSTONE AS SUPPORT FOR RECOVERY OF A MINED AREA IN THE IRON QUADRANGLE, MG

This work aimed to characterize the structure and composition of a Rupestrian field over ironstone as a basis for rehabilitation studies of areas degraded by iron mining activities. An ironstone outcrop at Serra do Rola Moca State Park, MG, was studied. In 30 plots of 2 m(2), 2,151 individuals were found, belonging to 32 species and 16 families, with a diversity of 2.45 nats/ind. Mean height was 15.7 +/- 16.3 cm, with 80% below 25 cm. The most important families were Orchidaceae, Poaceae, and Cyperaceae, and the species with highest importance value were Andropogon ingratus ( Poaceae), Lychnophora pinaster (Asteraceae), Bulbostylis fimbriata (Cyperaceae), Sophronitis caulescens (Orchidaceae), and Sebastiania glandulosa (Euphorbiaceae). We suggest that these species, together with those presenting clonal growth, such as grasses, sedges and epilythic orchids; facilitators, such as Stachytarpheta glabra and Mimosa calodendron; and those tolerant to heavy metals, such as Vellozia spp., be priority candidates in restoration programs in areas degraded by iron ore extraction.