Variations in chemical and physical properties of Amazon forest soils in relation to their genesis

Research output: Contribution to journalArticle


Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils.


  • C. A. Quesada
  • J. Lloyd
  • M. Schwarz
  • S. Patiño
  • T. R. Baker
  • C. Czimczik
  • N. M. Fyllas
  • L. Martinelli
  • G. B. Nardoto
  • J. Schmerler
  • A. J. B. Santos
  • M. G. Hodnett
  • R. Herrera
  • F. J. Luizão
  • Almut Arneth
  • G. Lloyd
  • N. Dezzeo
  • I. Hilke
  • I. Kuhlmann
  • M. Raessler
  • And 9 others
  • W. A. Brand
  • H. Geilmann
  • J. O. Moraes Filho
  • F. P. Carvalho
  • R. N. Araujo Filho
  • J. E. Chaves
  • O. F. Cruz Junior
  • T. P. Pimentel
  • R. Paiva
External organisations
  • External Organization - Unknown
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography
Original languageEnglish
Pages (from-to)1515-1541
Issue number5
Publication statusPublished - 2010
Publication categoryResearch