1-2). Nonetheless, on occasion it will be necessary to refer to the regions based on the natural ecosystems, such as tropical jungles, pampas and cerrados, mangroves, etc. Due to the great diversity of ecosystems and climates in the region, LAC is characterized by a great diversity and complexity of agroecological zones, as well as types of production associated with these zones. Table 1-3 shows the agroecological zones of the region as well as the principal types of agriculture in these zones.

1.4 Global Context: Main Trends

To perform a critical evaluation of AKST systems and of agriculture in Latin America and the Caribbean, one must know the context in which these systems operate.

          Since the 1950s, the combined effects of three revolutions- technological, economic and cultural-have been giving rise to new realities (Castells, 1996), shaped by old and new contradictions, which transform (in a differentiated manner) the many "worlds" that coexist in our region (Capra, 1982; Restivo, 1988; Dicken, 1992; Sachs, 1992; Barbour, 1993; Najmanovich, 1995; Castells, 1996, 1997, 1998; Chisholm, 1996; Escobar, 1998a; Wallerstein, 1999; Busch, 2000, 2001; Rifkin, 2000; Mooney, 2002; Santamaría-Guerra, 2003). The main global trends can be grouped as: (1) technological

changes, (2) macroeconomic changes, especially globalization, (3) the emerging resistance movements with new outlooks and (4) environmental/natural changes.

          Among the main technological changes we see the emergence of an immaterial economy dependent mainly on an intangible factor-information-and on the communications infrastructure. From this technology is emerging a digital hemisphere whose dynamic is dependent on virtual networks of power through which capital, decisions and information flow. The rise of the network concept, supported by new possibilities of digital technology and communications infrastructure, has implications for the management of interdisciplinary, inter-institutional and international projects. Also worthy of special note are the emerging scientific and technological possibilities (robotics, new materials, nanotechnology, cellular and molecular genetics, information technology, etc.) that point simultaneously to new advances important for humankind and to new inequalities within and among social groups and nations.

           Globalization has accelerated the construction of a world economic and political order whose corporate and transnational nature is becoming consolidated under the dominant influence of actors with global interests and expansionist ambitions. This model has led to the decline of the