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ND-06 Abstract

Nitrogen and Phosphorus Dynamics in Forests and Converted Forest Sites in the Amazon Basin: A Review and Synthesis of Previous Research

Henry L. Gholz — University of Florida (US-PI)
Francisco DeAssis Oliveira — UFRA (SA-PI)


The principal objectives of this proposal are to:

  • Review and synthesize previous research that has examined nitrogen (N) and phosphorus

    (P) pools and cycling patterns in Amazonian forests and cerrado,

  • Review and synthesize previous research addressing changes in N and P dynamics caused by

    conversion of forest and cerrado to other land-uses (e.g., pasture, secondary forest after

    logging, agroforestry systems, and tree plantations), and

  • Outline gaps in present knowledge and suggest future research directions in this area.

    Over the past thirty years, road building and government-backed colonization schemes in

    the Amazon Basin have resulted in increases in human population and rising pressures on

    natural resources.

Concurrent with this modern colonization of the Amazon has been a growing body of

knowledge about nutrient dynamics in Amazonian forests and the affects of forest

conversion on nutrient storage and cycling. As this body of literature has expanded, it is

clear that the compilation and synthesis of results from these studies is essential to

provide researchers and research managers with a concise reference to previous work (much

of which is available only in Portuguese), identify gaps in knowledge and potential future

research directions, as well as provide policy makers, landowners and land managers with

information pertinent to the ecological effects of land use changes in the region.

Continuing conversion of forests to other land uses in the Amazon Basin is inevitable,

especially in areas that are close to major rivers, highways, or cities. Therefore, it is

essential to address the long-term impacts of forest conversion on nutrient pools and

cycling rates and patterns to better understand the limits to productivity once forest

cover has been removed. Nitrogen (N) and phosphorus (P) are two elements of particular

importance, particularly since their availability for plant uptake are thought to limit

primary production (or carbon [C] fixation rates) of ecosystems based on the highly

weathered Oxisol and Ultisol soils which cover the majority of the Amazon Basin.

We propose to produce at least one co-authored review paper suitable for publication in

the journal Ecological Applications; it is not yet clear whether more than one publication

will be warranted, although the three project objectives are suitable to this if the

volume of the synthesis in the three sub-areas is sufficient. The publication(s) will also

be produced in Portuguese for dissemination and use in Brazilian institutions. In

addition, we will publish the results, in part or in whole, in NASA/LBA proceedings as

appropriate and contribute the results to the NASA/LBA database (LBA-ECO DIS).

Research Team

This literature review and analysis will be conducted through an international

collaboration with researchers from institutions in the U.S., Brazil, and Canada. The

three investigators of this project collectively have literature available from a wide

range of sources and countries and in several languages. The investigators worked together

from 1993-1996 at the Curuá-Una Research Station (100 km east of Santarém, Pará) in a

project that examined plant-induced changes of soil nutrient dynamics under native forest

and tree plantations under a USDA competitive grant. The proposed project is designed to

be completed within one year.

  • Henry Lewis Gholz, Professor of Forest Ecology and Graduate Coordinator, School of

    Forest Resources and Conservation, University of Florida, Gainesville, FL 32611 USA


  • Francisco de Assis Oliveira, Professor of Forest Ecology, Department of Forestry,

    Faculdade de Ciências Agrárias do Para (FCAP) C.P. 917 Belém, Pará, Brazil 66093-000,

    fax 55 91 226 3814, phone 55 91 226 3493

  • C. Ken Smith, Post-Doctoral Associate, Centre de Recherche en Biologie Forestière,

    Pavillon Abitibi-Price, Université Laval, Sainte-Foy (Québec), Canada G1K 7P4, (418)


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