Pathway of rare-earth elements in a Brazilian forestry fragment

• Published in: Journal of alloys and compounds 2002-10, Vol.344 (1), p.21-26
• Main Authors: França, Elvis J., De Nadai Fernandes, Elisabete A., Bacchi, Márcio A., Tagliaferro, Fábio S.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Forestry; Fundamental and applied biological sciences. Psychology; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Instrumental neutron activation analysis; Rare-earth elements; Tropical forest
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(02)00298-0

The Mata de Santa Genebra is a fragment of semi-deciduous tropical forest located in an urban area of São Paulo State, Brazil. Potential sources of rare-earth elements (REE), such as oil refinery, agricultural activities and high-traffic roads, are situated close to this region. In this study, the central portion of the fragment dominated by Pachystroma longifolium and Esenbeckia leiocarpa was evaluated for the distribution of La, Ce, Nd, Sm, Eu, Tb and Yb in the soil, leaf and litter sub-compartments applying instrumental neutron activation analysis (INAA). Leaf/soil concentration ratios (CR) of P. longifolium were higher than those obtained for E. leiocarpa by a factor of 20. Considering leaf/litter concentration ratios, no retranslocation of these elements was noticed for both species before litterfall. Accumulation of REE and typical distribution patterns were observed for the plant sub-compartments. The high La content may be attributed to preferential uptake by these plants or to external atmospheric sources.