Final report on studies of nutrient cycling on white and black water areas in Amazonia

Abstract

Studies were conducted near Manaus, Brazil in cooperation with INPA to try to establish how nutrient cycling influences the formation of black water and white water. The studies measured the rate of decay of Caryocar villosum leaves on spodosol and oxisol terrestrial and aquatic sites when the leaves were untreated, and treated with a bacteriostat, or insecticide or fungicide. It also measured litter, animal populations, and the elemental content of ten biologically important elements in soils and decomposing litter. Results show considerable differences in the rates of decay and the agents and end products of decay which indicate that black water and white water formation are closely tied to the rate and type of decay and to basic soil types and their associated vegetation, except for the rediments in white water.

Compositions and fluxes of particulate organic material in the Amazon River1

“…The A14C (Stuiver and Polach 1977) of this sample (+ 227 + 19G) closely matches the 1983 value for atmospheric CO2 in the (Nydal and Lovseth 1983). This result is to be expected for rapidly recycled leaf material (Stark and Holley 1975;Herrera et al 1978) and therefore supports the previous CPOM source assignments.…”

On the leaf litter community of the Amazonian blackwater stream Tarumazinho

“…The consumption therefore represents fungal and bacterial respiration. The ash content of the samples was about 5% by weight indicating that the litter was in the early stages of decomposition (Stark & Holley 1975).…”

On the dynamics, floristic subdivision and geographical distribution of várzea forests in Central Amazonia

“…Xingu Igapó and Xingu terra firme (Campbell et al 1986); 8. Várzea of the Rio Guamá, Belém (Pires & Koury 1959) and Bragantina terra firme (Denich 1989 All investigated stands, however, possess alluvial soils deposited by the nutrient rich water of the Amazon river and show therefore comparable nutrient conditions (Stark & Holley 1975;Worbes 1986).…”