Forest and Cultivated systems
"Forest systems are lands dominated by trees; they are often used for timber, fuelwood, and non-timber forest products. The map shows areas with a canopy cover of at least 40% by woody plants taller than 5 meters. Forests include temporarily cut-over forests and plantations but exclude orchards and agroforests where the main products are food crops. The global area of forest systems has been reduced by one half over the past three centuries. Forests have effectively disappeared in 25 countries, and another 29 have lost more than 90% of their forest cover. Forest systems are associated with the regulation of 57% of total water runoff. About 4.6 billion people depend for all or some of their water on supplies from forest systems. From 1990 to 2000, the global area of temperate forest increased by almost 3 million hectares per year, while deforestation in the tropics occurred at an average rate exceeding 12 million hectares per year over the past two decades.
Cultivated systems are lands dominated by domesticated species and used for and substantially changed by crop, agroforestry, or aquaculture production. The map shows areas in which at least 30% by area of the landscape comes under cultivation in any particular year. Cultivated systems, including croplands, shifting cultivation, confined livestock production, and freshwater aquaculture, cover approximately 24% of total land area. In the last two decades, the major areas of cropland expansion were located in Southeast Asia, parts of South Asia, the Great Lakes region of eastern Africa, the Amazon Basin, and the U.S. Great Plains. The major decreases of cropland occurred in the southeastern United States, eastern China, and parts of Brazil and Argentina. Most of the increase in food demand of the past 50 years has been met by intensification of crop, livestock, and aquaculture systems rather than expansion of production area. In developing countries, over the period 1961–99 expansion of harvested land contributed only 29% to growth in crop production, although in sub-Saharan Africa expansion accounted for two thirds of growth in production. Increased yields of crop production systems have reduced the pressure to convert natural ecosystems into cropland, but intensification has increased pressure on inland water ecosystems, generally reduced biodiversity within agricultural landscapes, and it requires higher energy inputs in the form of mechanization and the production of chemical fertilizers. Cultivated systems provide only 16% of global runoff, although their close proximity to humans means that about 5 billion people depend for all or some of their water on supplies from cultivated systems. Such proximity is associated with nutrient and industrial water pollution."
Source & ©
Millennium Ecosystem Assessment
 Synthesis Report (2005),
Chapter 1, pp.29-30
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