ATMOSPHERIC INPUTS OF NUTRIENTS AND POLLUTANTS INTO URBAN FOREST ECOSYSTEM, MACIÇO DA PEDRA BRANCA - RJ / ENTRADAS ATMOSFÉRICAS DE NUTRIENTES E POLUENTES EM UM ECOSSISTEMA FLORESTAL URBANO, MACIÇO DA PEDRA BRANCA - RJ

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The cycling of nutrients in forest ecosystems is a dynamic exchange process between biotic and abiotic components. Pluviometric precipitation is one of the processes which affect cycling, representing one important source for the input of nutrients and potential pollutants in ecosystems situated close to polluting sources. The cycling profile and the availability of nutrients in a forest region influence the physiology, the biology of plants and help to understand seasonal processos. The present study was performed in a region of the Atlantic Forrest (Mata Atlântica) in the west zone of Rio de Janeiro. The atmospheric inputs of nutrients and pollutants were measured by the analysis of rainwater, incident to the forest and that fraction penetrating the dossel. Water samples were collected by means of randomly distributed pluviometers. Elemental determinations were performed by optical emission spectrometry (OES) and by mass spectrometry (MS), both using inductively coupled plasma (ICP) as excitation/ionization source. Determination of anions was made by ion chromatography with conductimetric detection after chemical suppression. Pluviometric precipitation, during the time period studied from 11/21/02 to 11/07/03, was in an average 1708 mm, being the mean value intercepted by the canopy about 14%. Considering the input of nutrients, the largest contributions are from K and Ca with 10.3 and 4.8 kg/ha/year, respectively. As regard to minor nutrients, Zn (375 g/ha/ano) and Mn (46.2 g/ha/ano) gave the major inputs. Calculated enrichment factors (EF) varied strongly from one element to the other. High values (EF >100) were observed for some heavy metals (p.ex. Cd, Sb, Hg), indicating the proximity of polluting sources, as could be expected from the close vicinity of the studied area to the main city of do Rio de Janeiro.

ASSUNTO(S)

precipitacao atmosferica icp oes atmospheric precipitation elementos traco icp-ms icp oes icp-ms trace elements

ACESSO AO ARTIGO

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