Linking ecologists and traditional farmers in the search for sustainable agriculture (miguel a altieri)

The majority of farmers in the developing world tend small plots in marginal environments, using indigenous agricultural methods. These diversified agroecosystems have emerged over centuries of biological evolution, and represent the experiences of farmers interacting with their environment without access to external inputs, capital, or scientific knowledge (Wilson 1999). Using selfreliance and experiential knowledge, these farmers have developed systems that generate sustained yields to meet their subsistence needs (Wilken 1987; Denevan 1995). Part of this performance is linked to the high levels of agrobiodiversity, which in turn positively influence traditional agroecosystem function (Vandermeer 2003).
The continued existence of millions of hectares of raised fields, terraces, polycultures, and agroforestry systems represent a successful indigenous adaptation to difficult environments, and are a tribute to the creativity of rural farmers
(Altieri 1999; Figure 1). These microcosms of traditional agriculture offer promising models for other areas as they promote biodiversity, thrive without agrochemicals, and sustain year-round yields (Denevan 1995).
Traditional crop management practices represent a rich resource for ecologists interested in understanding the mechanisms at work in complex agroecosystems, such as the interactions between biodiversity and ecosystem function or the use of natural succession as templates to design this type of system. It is only recently that ecologists have recognized the virtues of traditional agroecosystems, where sustainability is based on complex ecological models.
An examination of the ways these farmers use biodiversity can speed the emergence of the principles needed to develop more sustainable systems. In fact, such studies have already helped several agroecologists create novel farm designs, well adapted to local circumstances (Altieri
2002). A key challenge involves the translation of these