Summary: 1466
Limnol. Oceanogr., 48(4), 2003, 1466­1475
2003, by the American Society of Limnology and Oceanography, Inc.
Bottom-up controls on bacterial production in tropical lowland rivers
Mari´a M. Castillo1
School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan, 48109-1115
George W. Kling
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109-1048
J. David Allan
School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan, 48109-1115
Abstract
The importance of organic carbon and inorganic nutrients in controlling bacterial production was investigated in
two tropical lowland rivers draining undisturbed forested catchments. Glucose (C), ammonium (N), phosphate (P),
leaf leachate, and algal leachate were added alone or combined to water collected from one clear-water (Cataniapo)
and one black-water (Autana) river of the Middle Orinoco basin, and bacterial production (BP) was measured at 0,
8, 24, and 36 h of incubation. The rivers have low pH (3.8­5.9) and conductivity (6.3­9.1 S cm 1
) and abundant
nitrogen (total N, 273­314 g L 1
) compared to phosphorus (total P, 3.6­5.5 g L 1
). BP was significantly stim-

Source: Allan, David - School of Natural Resources and Environment, University of Michigan

Collections: Environmental Sciences and Ecology