servation programs have not been initiated properly and biodiversity legislation has not been implemented to promote protection (http://www.cbd.int/reports).

The expansion of agricultural production and the intensive use of inputs over recent decades in CWANA countries are considered to be major contributors to the loss of biodiversity (FAO, 1996a). At the same time, certain agricultural ecosystems can serve to maintain biodiversity, which may create conditions favorable for many species that might be endangered by fallowing or changing to a different land use, such as forestry. Agricultural food and fiber production is also dependent on many biological services. This can include, for example, providing genes for developing improved crop varieties and livestock breeds, crop pollination and soil fertility provided by microorganisms.

The preservation and enhancement of biodiversity pose a major challenge for agricultural policy makers, as population and demand for food increase. Policy makers will need to find ways of minimizing the conflicts between expanding production and maintaining biodiversity, enhancing the many complements between agriculture and biodiversity and finding ways to prevent the loss of biodiversity on agricultural land (Pagiola and Kellenberg, 1997). For a growing number of CWANA countries, protecting and enhancing biodiversity are becoming important in their domestic and international agroenvironmental policy objectives and actions, in response to growing public concern. In practice, government policies towards biodiversity involve balancing the tradeoffs between socioeconomic values and biodiversity conservation. Typically, policies with low ambition can avoid short-term costs but may lead to more costs over the long term, such as risks to agricultural production from genetic erosion. More ambitious policies and targets towards biodiversity conservation will require scientific research, including developing biodiversity indicators. Indicators can help support decisions by providing information about the risks and degrees of sustainability associated with different options.

2.1.7.2 Introduction of modern varieties, case studies on wheat

For thousands of years, small-scale farmers have grown food for their own consumption-planting diverse crops,

recycling organic matter and following nature's rainfall patterns. The trend of switching from traditional agriculture to cash crop agriculture and monoculture is leading to a decline in local crops and varieties and the loss of traditional knowledge, farming and old varieties and landraces. At present, some minor crops are maintained by farming households on a small scale to supply their traditional food cultures. Harlan (1951) noted that "crop germplasm in Vavilovian Centers are vulnerable to loss due to technological and economic changes."

Until the 1950s, farming in CWANA relied upon farmers' accumulated knowledge of the local physical and social environment. At the end of the 1960s, introduced improved wheat started to replace local varieties, causing the loss of old and traditional wheat cultivars, especially in areas suitable for extensive agriculture. This replacement is the major cause of genetic erosion, which frequently occurs because the genes and gene complexes found in the diverse local varieties are not all contained in the modern seed (FAO, 1996a). The lack of extension, no national planning and policies and no local training for maintaining unique, local varieties and a wide range of ecological problems associated with agricultural practices have caused environmental pollution and biodiversity lost. Having the first national program and storage facilities, Turkey carried out an intensive survey and collection program, in 1968 and 1969, at the coastal regions to maintain the local wheat cultivars, which were being replaced rapidly by improved Mexican wheat (Sencer, 1975).

2.1.7.3 Expansion of agriculture and crop and plant diversity change

CWANA has mainly dryland and mountain ecosystems. Both are fragile and open to a rapid decline of biodiversity. The expansion of agricultural production into formerly uncultivated mountain lands or forest reduces the habitat for other species and leads to a decline or deterioration of ecosystems, particularly where the lands are only marginally suitable for agriculture. The threat to traditional crops will increase as cropland available for each household is reduced (Tan, 2002).

Degradation of habitat and loss of related biodiversity are already leading to irreversible situations. They are re-