Summary
The dynamics of the forest to the north of Manaus is tightly linked to that of the soil. The latosol that covers the plateau, which supports a dense forest, consists from top to bottom of: (a) a brown, clayey organic horizon (0.3 m), (b) a yellow horizon, very rich in clay but permeable (from 0.3 to 4 m), (c) a nodular horizon rich in Al and Fe oxides (from 4 to 9 m), and (d) a horizon which still preserves the sedimentary structures of the parent sandstone, where quartz is intensely dissolved and kaolinite crystallizes in pores. In perfectly flat areas, the clay of the organic horizon is destroyed by acidocomplexolysis, and the dissolved Al is transported vertically by the drainage water. A part of this Al is used to make the gibbsite nodules of horizon (c), and the rest is used to make kaolinite in horizon (d). Because aluminum is thus conserved within any vertical prism, the rate of destruction of horizon (a) is equivalent to the rate of advance of the kaolinization zone into the sediment: the latosol is said to be in equilibrium, the surface remains perfectly flat as it slowly sinks, the quantity of kaolinite increases with time, and the silica released by quartz dissolution in the whole profile is exported by drainage water to the water table. In contrast, near drainage axes, however small initially, the drainage becomes inclined toward the axis. Part of the Al released by acidocomplexolysis of horizon (a) is now exported to rivers, and Al is no longer conserved within any given prism. The rate of advance of the kaolinization zone (d) into the sediment now becomes less than the rate of destruction of horizon (a) and the surface sinks faster than that of the surrounding plateau. After this differential ‘podzolization’ has gone on long enough, it creates a network of ‘geochemical valleys’ characterized by convex slopes and bounded by sandy soils (campinas). The vegetation becomes sparser and sparser. At the end, only some bushes and lichens survive on the white sand.
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References
Aubert, G., and Segalen P., Projet de classification des sols ferrallitiques. Cah. ORSTOM, ser. Pédol. IV4 (1966) 97–112.
Boulet, R., Toposéquences de sols tropicaux en Haute-Volta. Equilibre et déséquilibre pédobioclimatique. Thèse Sc. Strasbourg et Mém. ORSTOM no 85, (1974).
Boulet, R., Humbel, F.X., and Lucas, Y., Analyse structurale et cartographie en pédologie. II. Une méthode d'analyse prenant en compte l'organisation tridimensionnelle des couvertures pédologiques. Cah. ORSTOM, ser. Pédol. XIX4 (1982) 323–339.
Boulet, R., Chauvel, A., and Lucas, Y.,Les systèmes de transformation en pédologie, Livre Jubilaire du Cinquantenaire de Ass. fr. Et. Sol (1984) 167–179.
Brazil. Ministerio das Minas e Energia. Departamento Nacional da Produçao Mineral. Projeto RADAMBRASIL. Levantamento de Recursos Naturais. Folha SA. 20, Manaus 1978.
Camargo, M.N., and Rodrigues, T.E., Guia de excursao do XVII Congresso Brasileiro de Ciencia do Solo. EMBRAPA-SNLCS 1979.
Chauvel, A., Os latossolos amarelos, alicos, argilosos dentro dos ecosistemas das bacias experimentais do INPA e da regiao Vizinha. Acta amazon. XII-3 (1982) 47–60.
Chauvel, A., Boulet, R., Join, P., and Bocquier, G., Aluminum and iron hydroxide segregation in nodules of latosols developed on tertiairy sediments (Barreiras group) near Manaus (Amazon Basin, Brazil), pp. 507–526. II. Int. Sem. on Lateritisation Processes. IAGUSP, Sao Paulo, 1982.
EUA-Department of Agriculture. Soil Survey Staff. Soil taxonomy. A. Basic system of classification for making and interpreting soil surveys. Washington. Soil Conservation Service (1975).
Guillaumet, J.L., Some structural and floristic aspects of the forest. Experientia43 (1987) 241–251.
Kahn, F., Architecture comparée de forêts tropicales humides et dynamique de la rhizosphère. Thèse Montpellier (1983).
Kahn, F., The distribution of palm trees as a function of local topography in Amazonian terre-firme forests. Experientia43 (1987) 251–259.
Klinge, H., Podzol soils in the Amazon Basin. J. Soil Sci. (1965) 96–103.
Klinge, H., and Ohle, W., Chemical properties of rivers in the Amazon area in relation to soil conditions. Verh. int. Ver. Limnol., Stuttgart15 (1964) 1067–1076.
Leenheer, J.A., Origin and nature of humic substances in the waters of the Amazon river basin. Acta amazon.3 (1980) 513–526.
Lucas, Y., Chauvel, A., Boulet, R., Ranzani, G., and Scatolini, F., Transiçao latossolos-podzois na região de Manaus Amazonia. Brasil. R. Bras. Ci Solo. Campinas 8–3 (1984) 325–335.
Pedro, G., Caractérisation générale des processus de l'altération hydrolytique. Sciences du Sol. Versailles 2–3 (1979) 93–105.
Prance, G.T., and Schubart, H., Nota preliminar sobre a origem das Campinas abertas de areia branca do baixo Rio Negro. Acta amazon.4 (1977) 567–570.
Ranzani, G., Identificação e caracterização de alguns solos da Estaçao Experimental de Silvicultura Tropical do INPA. Acta amazon.1 (1980) 7–41.
Salati et al., Towards a water balance in the Central Amazonian region. Experientia43 (1987) 222–233.
Schubart, H., Franken, W., and Luizao, F., Uma floresta sobre solos pobres. Cienc. Hoje-SBPC (1984) 26–32.
Sioli, H., Gewässerchemie und Vorgänge in den Böden im Amazonasgebiet. Naturwissenschaften41 (1954) 456–457.
Sioli, H., Hydrochemistry and geology in the Brasilian Amazon region. Amazoniana 1–3 (1968) 267–277.
Sioli, H., and Klinge, H., Über Gewässer und Böden des brasilianischen Amazonas-Gebietes. Erde3 (1961) 205–219.
Sombroek, W. G., Amazon soils: a reconnaissance of soils of the Brazilian Amazon Region. Center of Agricultural Publication and Documentation Wageningen. Holland 1966.
Swindale, L. D., and Jackson, M. L., Genetic processes in some residual podzolised Soils of New-Zealand. 6e Congr. int. Sci. Sol, Paris (1956) 233–239.
Turenne, J. F., Mode d'humification podzolique dans deux toposéquences guyanaises. Thèse Nancy et Mém. ORSTOM no84 (1977).
Villa Nova, N. A., Salati, E., and Matsui, E., Estimava da evapotranspiraçao na Bacia Amazonica. Acta amazon.2 (1976) 215–228.
Volkoff, B., Matsui, E., and Cerri, C. C. Discriminação isotopica do carbono no humus de latossolo e podzol da região Amazonica do Brasil. Regional Colloquium on Soil Organic Matter Studies. CENA-USP-PROMOCET (1982) 147–153.
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Acknowledgments. The authors are indebted to Dr E. Merino (Dept. of Geology, Indiana University) for helpful criticisms and suggestions. This research was carried out in I.N.P.A. (Instituto Nacional de Pesquisas da Amazonia) and was financially supported by the CNPq-CNRS/ORSTOM conv.
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Chauvel, A., Lucas, Y. & Boulet, R. On the genesis of the soil mantle of the region of Manaus, Central Amazonia, Brazil. Experientia 43, 234–241 (1987). https://doi.org/10.1007/BF01945546
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DOI: https://doi.org/10.1007/BF01945546