Nitrous oxide flux following tropical land clearing

The importance of seasonal cycles of N 2 O flux from tropical ecosystems and the possibility that tropical deforestation could contribute to the ongoing global increase in N 2 O concentrations were assessed by measuring N 2 O flux from forest, cleared land, and pasture over an annual cycle in the central Amazon. A pasture that had been converted from tropical forest had threefold greater annual N 2 O flux than a paired forest site; similar results were obtained in spot measurements in other pastures. If these results are general, such tropical pastures represent a globally significant source of increased N 2 O.