Agrobiodiversity

The Convention on Biological Diversity (CBD) defines biodiversity as the variety of life on Earth and the natural patterns it forms. Our world's wide variety of plants, animals, and microorganisms and the genetic diversities within each species; the varieties of patterns they form in ecosystems; and the valuable products, services, and opportunities they provide are increasingly threatened by human exploitation. The CBD calls on all countries to conserve and sustainably use biodiversity in collaboration with local actors, such as farmers, because they take most of the actions that affect biodiversity.

Agriculture greatly affects biodiversity. Much of the world's farmlands are cultivated by small-landholding farmers in the developing countries, and the practices of these farmers affect biodiversity in a large part of the world. On the one hand, the practices of these farmers, such as the slash-and-burn agriculture of shifting cultivators in forest ecologies, have been derided as the primary cause of biodiversity loss. The conservation community has consequently called for biodiversity rehabilitation in such regions. On the other hand, there is an influential body of primary-research-based literature that is challenging this discourse on biodiversity endangerment by farmers in the developing world and instead emphasizes what can be learned from these farmers about in situ biodiversity conservation and sustainable use at both farm and landscape levels. This literature indicates that the farms and farming landscapes of hundreds of millions of farmers in developing countries are characterized by great diversity compared with the large uniform fields of farmers in the more developed world. Researchers and practitioners have noted the considerable extent to which small-landholding agriculture is related to the details of the landscape in which it occurs. Such agricultural strategies are the outcome of an accumulated body of local knowledge derived from experience and experimentation. This leads many small-landholding farmers to use the diversities of plant life on their fields to meet agronomic and livelihood goals; make optimal use of variations in agroecological conditions on their fields (such as differences in microclimate, soil [Page 50]properties, and vegetation); and modify or transform their landscapes to produce a great variety of crops and genetic diversities of particular crops and also create local crop varieties (known as land races). The varieties of crops cultivated are not static. They are conditioned by ecological, cultural, and socioeconomic factors and thus change through time.

This diversity of crops and other plants used by or useful to people in actively managed agricultural ecosystems is referred to as agrobiodiversity. The diversity of crops and other plants found in the fields of many small-landholding farmers is the result of the interaction of three factors: (1) biophysical diversity in the landscape; (2) the diversity, flexibility, and adaptability of agricultural management practices; and (3) the diversity of socioeconomic processes that condition the organization of agriculture. Biophysical diversity in landscapes refers to diversities of the biotic environment (such as plant genetic resources) and the abiotic environment. The diversity, flexibility, and adaptability of agricultural practices for managing this biophysical diversity are based on indigenous ecological knowledge and include selection and management of crop and plant varieties; combinations and rotations to suit particular ecological niches; management of successional vegetation during fallows; management of slopes, water, and soil fertility; and management of weeds, pests, and diseases. The agricultural factors and processes that affect biodiversity include the different types and modes of access to and control over land, labor, and manufactured capital—all of which vary by the income, gender, generation, and citizenship of farmers and may facilitate or undermine biodiversity. Processes relating to government policies and the uncertainties and risks of markets are also important aspects of agricultural organization.

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