Unexpected changes in soil phosphorus dynamics along pasture chronosequences in the humid tropics

Alan R. Townsend, Gregory P. Asner, Cory C. Cleveland, Margaret E. Lefer, Mercedes M.C. Buslamante

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

Phosphorus (P) is widely believed to limit plant growth and organic matter storage in a large fraction of the world's lowland tropical rain forests. We investigated how the most common land use change in such forests, conversion to cattle pasture, affects soil P fractions along pasture chronosequences in the central Brazilian Amazon and in southwestern Costa Rica. Our sites represent a broad range in rainfall, soil type, management strategies, and total soil P (45.2-1228.0 μg P/g soil), yet we found some unexpected and at times quite similar changes in soil P in all sites. In the Brazilian sites, where rainfall is relatively low and pasture management is more intense than in the Costa Rican sites, significant losses in total soil P and soil organic carbon (SOC) were seen with pasture age on already P-deficient Oxisol and Entisol soils. However, P losses were from inorganic soil P fractions, while organic forms of soil P remained constant or increased with pasture age, despite the declines in SOC. In Costa Rica, SOC remained constant across the Oxisol sites and increased from forest to pasture on the Mollisols, while soil organic P increased with pasture age in both sequences.

Original languageEnglish (US)
Pages (from-to)XCXXXV-XCXXXVI
JournalJournal of Geophysical Research D: Atmospheres
Volume107
Issue number20
StatePublished - Dec 1 2002
Externally publishedYes

    Fingerprint

Keywords

  • 1615 Global Change: Biogeochemical processes (4805)
  • 1625 Global Change: Geomorphology and weathering (1824, 1886)
  • 1630 Global Change: Impact phenomena
  • 1699 Global Change: General or miscellaneous
  • Land use change
  • Pastures
  • Phosphorus
  • Soils
  • Tropics

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Townsend, A. R., Asner, G. P., Cleveland, C. C., Lefer, M. E., & Buslamante, M. M. C. (2002). Unexpected changes in soil phosphorus dynamics along pasture chronosequences in the humid tropics. Journal of Geophysical Research D: Atmospheres, 107(20), XCXXXV-XCXXXVI.