Intensive agriculture generates significant environmental effects. Irrigation ditches and rice fields (fields with irrigated rice) become deposits of organic, chemical waste (such as salts) and pathogenic microorganisms. In general, intensive agriculture extends to the cost of the felling of trees and forests, which are replaced by cultivation areas. Deforestation is accompanied by the loss of environmental diversity (see Srivastava, Smith and Forno, 1999). Agricultural economies always specialize and focus on one or some basic caloric sources, such as rice, and animals that help in agricultural work. Since tropical horticulturists usually cultivate dozens of plant species simultaneously, their land tend to reflect the botanical diversity found in a rainforest. Agricultural lands, in contrast, reduce ecological diversity when cutting trees and concentrating only on some basic foods. Such a crop specialization is characteristic of both the farmers of the tropics (eg, Indonesian rice farms) and those found outside them (for example, irrigated farms of the Middle East). In the tropics, the forage and horticultural diets are usually more diverse; However, its control is less sure than in the farmers’ diets. These try to reduce the risk in production by favoring stability through a reliable annual harvest and long-term production. Of course, even with agriculture, there is a possibility that basic crop can fail, and it is in famine. Tropical foragers and horticulturists, in contrast, try to reduce the risk by leaning on multiple species and benefiting from ecological diversity. The agricultural strategy is to put all the eggs in a great and very reliable basket; That of tropical foragers and horticulturists is to have many smaller baskets, some of which can fail without endangering subsistence. The agricultural strategy takes sense when there are many children who raise and adults for feeding. Of course, foraging and horticulture are associated with smaller, scattered and mobile populations. Agricultural economies also pose a series of regulatory problems, and often emerge from central governments for resol-
see them. Among these problems are distribution and access to water. With a greater population that occupies more valuable lands, farmers are more likely to come into conflict than foragers and horticultural.