Growing Periandra mediterranea on post-mining substrate : native Fabaceae with potential for revegetation of degraded rupestrian grasslands in Brazil.

Abstract

Recovery of degraded areas of rupestrian grasslands is hampered mainly by the limited knowledge regarding substrate management and the biology of native species suitable for revegetation of these areas. Th e aim of our study was to examine the establishment and growth of Periandra mediterranea in diff erent textures of lateritic substrate from a mining-degraded area. Th e growth of P. mediterranea was evaluated using fi ne and coarse laterite, both with and without the addition of topsoil. Survival, dry biomass, content of chemical elements and nodulation were evaluated in ten individuals per treatment sixteen months after planting. Although the substrate has low nutrient content, yet high metal concentrations, all plants survived. Plants growing on coarse laterite had 140 % greater biomass than those growing on fi ne laterite. Th e addition of topsoil increased biomass in coarse and fi ne laterite by 46 and 151 %, respectively, and doubled the number of nodulated plants, regardless of grain size. Th e biomass accumulation of P. mediterranea to a dystrophic substrate revealed its potential for use in the revegetation of degraded areas of rupestrian grasslands. Furthermore, the addition of topsoil facilitated the association of P. mediterranea with nitrogen-fi xing bacteria, and increased its growth and capacity to improve substrate fertility.