Biogeochemical dynamics following land use change from forest to pasture in a humid tropical area (Rondĵnia, Brazil): a multi-element approach by means of XRF-spectroscopy.

Forest burning for pastures in tropical areas represents an important component of biogeochemical cycles. In order to provide information concerning chemical modifications after forest burning, in this local study the total contents of 29 elements in topsoils were analyzed when forest is changed to pasture land. The work was carried out in 1999 in Rondĵnia state (Brazilian Amazon Basin) focussing on a native forest site and four neighboring pastures established in 1987, 1983, 1972 and 1911 after forest conversion.