The increasingly adverse effects of human activities on the
earth's land, water, atmospheric, and biotic resources have clearly demonstrated
that a new attitude of stewardship and sustainable management is required if our
global resources are to be conserved and remain productive. Nowhere is this need
more urgent than in the world's humid tropics. Its populations, many subsisting
at or below the poverty level, will continue to rely on the resource base to
meet their needs. That base must be stabilized while becoming increasingly
productive. Thoughtful and prompt actions, especially positive policy changes,
are required to break the current pattern of unplanned deforestation in the
humid tropics, to reverse environmental degradation caused by improper or
mismanaged crop and animal production systems, and to revitalize abandoned
At the request of the U.S. Agency for International Development
(USAID), the National Research Council's Board on Agriculture and the Board on
Science and Technology for International Development convened the 15-member
Committee on Sustainable Agriculture and the Environment in the Humid Tropics.
The U.S. Environmental Protection Agency also provided support, emphasizing its
interest in the global environmental implications of the problem.
The study responds to the recognized need for sustainable land
use systems that (1) maintain the long-term biological and ecological integrity
of natural resources, (2) provide economic returns at the farm level, (3)
contribute to quality of life of rural populations, and (4) integrate into
national economic development strategies. In particular, the committee was asked
to identify and analyze key problems of agricultural practices that contribute
to environmental degradation and result in declining agricultural production in
humid tropic environments.
The committee began its work in March 1990. It sought to
understand the overarching environmental, social, and policy contexts of land
conversion and deforestation-and the promise of sustainable land uses-by
integrating the views of experts in the broad areas of agriculture, ecology, and
social sciences. Its work focused on the range of land use systems appropriate
to the forest boundary, an area where agriculture and forestry merge in a
continuum of production types involving trees, agricultural crops, and animals.
The committee addressed intensive, high-input agriculture only as it relates to
common environmental problems. The committee undertook supplemental analyses of
tropical forest land use policies and the effects of tropical land use on global
climate change. We sought a wide range of scientific data, specialized
information, and expert views to address our broad charge.
A critical component of the humid tropics equation that was not
within the scope of the study is human population. The committee acknowledges
population dynamics as a major factor in achieving sustainable land use and
development in the humid tropics; the land use systems it describes fit a broad
range of population densities. We stress the importance of population issues,
particularly in this region of the world, but an analysis of population
densities, pressures, and trends was not part of our study, nor does the
composition of the committee reflect the demographic expertise necessary to
address population issues.
This report, Sustainable Agriculture and the Environment in the
Humid Tropics, will contribute to the elusive "solution" to tropical
deforestation through its outline of a variety of approaches to tropical land
use and conservation. Each land use option would take advantage of the
opportunities inherent in physical resource patterns, labor, market
availability, and social setting, and each would contribute to the common goal
of sustainability in the humid tropics.
The land use options scheme in Chapter 2 and its accompanying
table for evaluating land use attributes can be used as a guide in decision
making. The presentation makes the information usable by in-country decision
makers, from the local level on up, as well as by governmental and
non-governmental agencies. We believe the information in this report will be
helpful to researchers, planners, and policymakers in industrialized countries
and in developing countries.
Part One is the committee's deliberative report. It emphasizes
the restoration of degraded land, the importance of general economic growth as
an alternative to forest exploitation, and the need for comprehensive management
of forest and agricultural resources. The underlying premise of the committee's
work is that under conditions of economic and social pressure, what is not
managed today is at risk of being lost tomorrow.
Within Part One, the Executive Summary discusses the findings of
the committee and presents key recommendations. Chapter 1 describes the humid
tropics, the consequences of forest conversion and deforestation, environmental
factors affecting agriculture, and the fostering of sustainable land use in the
humid tropics. Chapter 2 discusses major land use options that local, regional,
and national managers might choose in making decisions to achieve food
production goals, maintain or increase local income levels, and protect the
natural resource base. Chapter 3 discusses technical research needs and presents
recommendations on land use options. Chapter 4 presents policy imperatives to
promote sustainability. The Appendix to Part One presents a discussion of
emissions of greenhouse gases associated with land use change.
To enhance its understanding, the committee commissioned a
series of country profiles to gather information on land use and forest
conversion in different countries, to evaluate general causes and consequences
within specific contexts, to identify sustainable land use alternatives, and to
compare policy implications. Seven country profiles are presented in Part Two.
Authors review agricultural practices and environmental issues in Brazil, Cdlvoire, Indonesia, Malaysia, Mexico, the Philippines, and Zaire.
The committee's intent in this report is to make a positive
statement about the potential benefits of sustainable agriculture in the humid
tropics, rather than to condemn the forces that have contributed to the current
situation. It is an attempt to promote the restoration and rehabilitation of
already deforested lands, to increase their productivity, and to explore the
policy changes required to take the next steps toward sustainability. Guidelines
for future research and policy, whether for conserving natural ecosystems or for
encouraging sustainable agroecosystems, must be designed with a global
perspective and within the context of each country's environment, history, and
The committee underscores the fact that sustainable agriculture
in any given country will consist of many diverse production systems, each
fitting specific environmental, social, and market niches. Some alternatives
require higher inputs, labor, or capital-depending on their makeup, resource
base, and environment-but each must become more sustainable. Conversely, each
system can contribute toward the sustainability of the agricultural system in
general by helping to meet the varied and changing needs facing countries in the
humid tropics. To maintain a diversity of approaches while making real progress
toward common goals is the challenge that confronts all who are concerned with
the future of the lands and people of the humid tropics.
RICHARD R. HARWOOD, Chair Committee on
Agriculture and the Environment in the Humid