REAERATION OF A LOW-GRADIENT TROPICAL RAINFOREST STREAM IN THE AMAZON BASIN OF PERU

• Published in: Physical geography Vol. 19; no. 2; pp. 147 - 161
• Main Authors: Leuthart, Clara A., Mountain, Keith R., Spencer, Hugh T., Kosnik, Kristine E.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 01.03.1998; Taylor & Francis
• Subjects: Bgi / Prodig; Biogeography; Ecosystems and biological productivity; Physical geography; Peru; Amazonas River; Human impact; Deforestation; Oxygen; Ecosystem; Riparian vegetation; Water quality; Tropical rain forest; Forest; Stream; Heavy metals
• ISSN: 0272-3646; 1930-0557
• DOI: 10.1080/02723646.1998.10642645

Stream water quality data and atmospheric data were collected in a sub-basin of the Rio Napo in the Amazon rainforest of Peru. Previous investigations of a low-gradient stream indicated a diurnal dissolved oxygen curve that shows deoxygenation during daylight hours and reaeration during night hours. Data were collected to determine possible and most-probable causes of this unexpected pattern. Results of the investigation indicate that deoxygenation occurs during daylight hours because of the increase in stream temperature. Three agents of nighttime reaeration were found. The first and most significant was reaeration during rain events. Subsequent to the rain event, flow from a groundwater seep provided reaerated water to the site. In the absence of sufficient ground-water flow, nighttime condensate from the humid subcanopy atmosphere with nighttime drop in air temperature provided a source of well aerated water to the system. [Key words: water quality, dissolved oxygen, rainforest, Amazon, Peru.]