Cattle raising on pasturelands takes place in Southeast Asian countries, mainly in Indonesia (Kartasubrata, Part Two, this volume), the Philippines (Garrity et al., Part Two, this volume), and Thailand (Toledo, 1986), but it is not a significant factor in increasing deforestation since crop (mainly rice) production systems are dominant. Cattle and buffalo constitute the main work force for many farm operations. They are also used for meat and dairy production. Generally their forage consists of stubble in the dry season and herbaceous vegetation that grows during the rainy season on dikes and rice fields, along the roadside, and in marginal areas of community pastures.

In some countries vast expanses of originally forested land are increasingly being converted to low-forage-value savannah grasslands of Imperata cylindrica due to intensive shifting agriculture on acid and infertile soils ( Garrity et al., Part Two, this volume). In the Philippines, the human population of more than 5 million that subsists on shifting agriculture exert persistent pressure on formerly forested land that, due to frequent burning, is steadily being converted to I. cylindrica (Sajise, 1980). This same situation has been documented in Indonesia by Kartasubrata (Part Two, this volume). In parts of India, Bangladesh, and Nepal, overgrazing on communal lands is a major factor in productivity decline and soil erosion in the absence of incentives or institutions to control land access.

Livestock production in the humid zone of Africa is not important as an economic activity. Although some land is being cleared for cattle pasture, much of this land is not suitable for pasture beyond a few years because of soil erosion and low fertility (Brown and Thomas, 1990). Many cattle in equatorial Africa are also vulnerable to the effects of trypanosomiasis, which can cause poor growth, weight loss, low milk yield, reduced capacity for work, infertility, abortion, and often death. Annual losses in meat production alone are estimated to be $5 billion. This economic cost is compounded by losses in milk yields, tractive power, waste products that provide natural fuel and fertilizer, and secondary products, such as hides (International Laboratory for Research on Animal Diseases, 1991). Projects to eradicate the tsetse fly, which transmits the disease, are expensive and the use of large amounts of chemicals damages the environment (Goodland et al., 1984; Linear, 1985).

Some of the African breeds of cattle are genetically resistant to

Front Matter (R1-R16)

Executive Summary (1-18)

Part One (19-20)

1 Agriculture and the Environment in the Humid Tropics (21-65)

2 Sustainable Land Use Options (66-137)

3 Technological Imperatives for Change (138-158)

4 Policy-Related Imperatives for Change (159-191)

References (192-214)

Appendix: Emissions of Greenhouse Gases from Tropical Deforestation and Subsequent Uses of the Land (215-260)

Part Two: Country Profiles (261-264)

Brazil (265-351)

C te d (352-392)

Indonesia (393-439)

Malaysia (440-482)

Mexico (483-548)

The Philippines (549-624)

Zaire (625-658)

Glossary (659-674)

Authors (675-678)

Index (679-704)