01904naa a2200265 a 450000100080000000500110000800800410001910000200006024500780008026000090015830000110016752011640017865000200134265000130136265000100137565000100138565000160139565300170141165300180142865300140144665300120146070000210147270000200149377301250151318042272000-11-14       2000    bl uuuu     u00u1 u    #d1 aHAMILTON, S. K.  aKey biogeochemical processes in waters of the Pantanal wetland of Brazil.  c2000  ap.297.  aVast savanna floodplains such as the Pantanal cover extensive areas of South America, yet the biogeochemistry of these productive ecosystems remains little studied. Examples are presented to show key biogeochemical processes that are likely to control elemental cycling and ecosystem productivity in the Pantanal. Inflowing rivers bring particulate matter and nutrients from the uplands to their floodplains. Inorganic particulates and labile nutrients are quickly lost from the water, however, and thus riverine inflows may directly fertilize only limited areas. Most major solutes show little change due to biological processes and increase in concentration over long flow paths because of evaporative water losses. For much of the Pantanal, the seasonal inundation may stimulate nutrient regeneration as flood waters contact previously dry land, and when the flood waters undergo frequent transitions between oxic and anoxic conditions. Nutrient regeneration and uptake must be closely coupled because significant increases in labile nutrient concentrations are not usually observed, even when other solutes indicate substantial leaching of plant material.  abiogeochemistry  aPantanal  awater  aÁgua  aEcossistema  aArea alagada  aBiogeoquimica  aEcosystem  aWetland1 aCALHEIROS, D. F.1 aOLIVEIRA, M. D.  tIn: QUEBEC 2000: MILLENNIUM WETLAND EVENT, 2000, Quebec, Canada. Program with abstracts. Quebec: Elizabeth MacKay, 2000.