Summary
A series of plots in an Amazonian Rain Forest were trenched and treated with calcium to determine the effects of perturbation on numbers and activity of nitrifying bacteria. Although treatment resulted in between 2 and 26% of the nitrogen being lost from the humus layer, virtually all of it was in the NH +4 form. Numbers of nitrifying bacteria in the plots were relatively low. The low numbers and low activity of nitrifying bacteria is attributed to the low pH and high concentration of tannins in the root mat. It is hypothesized that the suppression of nitrifying bacteria results in nitrogen conservation in the rain forest.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allen, S.E., Grimshaw, H.M. Parkinson, J.A., Quarmby, C.: Chemical analysis of ecological materials. Oxford: Blackwell, 1974
Aubert, G., Tavernier, R.: Soil survey. In: Soils of the humid tropics. pp. 17–44. Washington, D.C.: National Academy of Science, 1972
Brunig, E.F., Heuveldop, J., Alder, D., Smith, J.: Structure and function of a rain forest in the international Amazon ecosystem project, floristic stratification and variation of some features of stand structure, and precipitation. Tropical Ecology
Jordan, C.F., Uhl, C.: Biomass of a “tierra firme” forest of the Amazon Basin. Oecologia Plantarum
Klinge, H., Medina, E., Herrera, R.: Studies on the ecology of Amazon caatinga forest in southern Venezuela. Acta cientifica Venezolana 28, 270–276 (1977)
Likens, G.E., Bormann, F.H., Johnson, N.M.: Nitrification: importance to nutrient losses from a cutover forested ecosystem. Science 163, 1205–6 (1969)
Medina, E., Herrera, R., Jordan, C., Klinge, H.: The Amazon project of the Venezuelan Institute for Scientific Research. Nature and Resources (UNESCO) 13 (no. 3), 4–6 (1977)
Rice, E.L., Pancholy, S.K.: Inhibition of nitrification by climax ecosystems. Amer. J. Bot 59, 1033–1040 (1972)
Rice, E.L., Pancholy, S.K.: Inhibition of nitrification by climax ecosystems. II. Additional evidence and possible role of tannins. Amer. J. Bot. 60, 691–702 (1973)
Rowe, R., Todd, R.L., Waide, J.: Microtechnique for most-probable-number analysis. Appl. Environ. Microbiol. 33, 675–680 (1977)
Smith, W.H., Bormann, F.H., Likens, G.E.: Response of chemoautotrophic nitrifiers to forest cutting. Soil Science 106, 471–473 (1968)
Stark, N., Jordan C.F.: Nutrient retention in the root mat of an Amazonian rain forest. Ecology 59, 434–437
Todd, R.L., Swank, W.J., Douglass, J.E., Kerr, P.C., Brockway, D.L., Monk, C.D.: The relationship between nitrate concentration in the southern Appalachian mountain streams and terrestrial nitrifiers Agro-Ecosystems 2, 127–132 (1975)