Water chemistry of the Amazon basin: The distribution of chemical elements among freshwaters

摘要: In the ecological studies of Amazon region, more attention has been paid to aquatic systems than terrestrial ones. particular, emphasis focused on freshwater nutrients. It appeared from outset that waters region were chemically and physically very heterogeneous, in general, poor predominated. The first classification Amazonian freshwaters (Sioli 1950) was based mainly optical characteristics, distinguished blackwater, with a high content humic compounds, whitewater, suspended sediment, clearwater, which is neither turbid suspensoids or coloured by compounds. However, chemical analyses showed spite generally low levels electrolytes, there considerable differences water chemistry between individual bodies particular type 1953, 1957a, 1968a). This found be case particularly clearwaters 1965a, Thus types could not clearly separated basis ionic composition. Differences were, however, closely linked geological, geochemical petrographic properties source regions (Gibbs 1967; Sioli 1968a; Fittkau 1974). Markedly acid, electrolyte-poor arise highly weathered tertiary sediments cover vast areas Central lowlands 1954b; 1964, Schmidt 1972a; Furch 1976; Irion Stallard 1978; & Junk 1980; 1980).