Global conservation efforts began in the 1950s in response to the rapid erosion of plant and animal genetic resources. A wide range of genetic resources of interest to food and agriculture have now been safeguarded and databases documenting this material continue to be built up.
Conservation is not an end in itself, but a means of ensuring that plant and animal genetic resources are available for use by present and future generations. The two basic approaches to conservation, once the resources are identified and characterized, are in situ and ex situ methods. In situ methods maintain plants and animals in their original habits whereas ex situ conservation maintains organisms outside their original habitats in facilities such as gene banks, cell cultures, botanical gardens or zoological parks. The two approaches are not mutually exclusive: different conservation systems can complement each other and ensure against the shortcomings of any one method. With the exception of the small number of varieties and breeds that are widely used, particularly in the developed world, experience shows that diversity is only secure when a variety of conservation strategies is employed.
Conserving plant genetic resources
Gene banks provide the principal means of storing plant genetic material. This ex situ system relies on three methods of storing the material:
Under ideal conditions, gene banks provide long-term but not indefinite storage. Both seeds and tissues deteriorate with age and plants must be grown periodically to generate fresh seeds and tissues for continued storage. Unfortunately, even the most sophisticated gene bank cannot always provide adequate security. Large collections of germplasm continue to be lost as a result of technical and financial shortcomings, or natural disasters. Power failures, inadequate documentation and evaluation, or failure to regenerate plants can result in massive losses of stored collections. Earthquakes, floods, social and political unrest also put gene banks at risk.
The biggest shortcoming of ex situ gene banks is that, once stored, plants are removed from the evolutionary process that they undergo in nature. There is no pressure from changing natural conditions or competition with other species. The ultimate aim of conservation is to maintain a dynamically evolving system. Therefore, while gene banks will continue to be vital to conservation, complementary systems, including in situ methods, are likely to assume greater importance in the future.
Conserving animal genetic resources
Ex situ conservation of animal genetic resources includes “cryogenic preservation techniques” — the collection and freezing in liquid nitrogen of semen, ova or embryos, or the preservation of DNA segments in frozen blood or other tissues. It also encompasses the captive breeding of wild or domesticated species in zoos or other locations away from their natural environment. Ex situ gene banks have similar advantages and disadvantages to those used to hold plant germplasm.
In situ conservation enables animal populations to continue to evolve and be selected for use in their natural environments. It is particularly important for species or within geographical regions where cryogenic preservation is not well developed or available. In situ conservation can be carried out at any level, in any country, without the need for special skills or technology. Properly planned, it can incorporate farmer and industry breeding as well as continued use of the resources.
Harmonizing conservation with human needs
In areas where biological resources are being depleted to meet the basic needs of local populations, in situ conservation must be reconciled with immediate human needs. Successful conservation depends upon meeting the needs of local people, while ensuring sustainability of the resource. Many approaches are feasible, but these three examples show how, based on scientific expertise and local knowledge and participation, genetic resources can be used and, at the same time, conserved and developed.
1 Better seeds and higher yields
Ethiopia is one of the world's richest centres of crop genetic diversity. Since 1988, its Plant Genetic Resource Centre has promoted on-farm conservation and enhancement of land races. Farmers, mostly women organized in cooperatives, receive training, technical support and backup from gene bank scientists and extension workers.
In northeastern Shewa and southeastern Welo, for example, farmers are helped to select seed for characteristics such as pest and disease resistance, size of kernel/head, earliness of ripening and other criteria of local importance to plant the next season. Plants grown from these seeds are harvested to provide the future seed supply. After three to five seasons of selection and multiplication, crop yields usually improve.
The farmers have access to the genetic resources of the centre's gene bank, as well as technical assistance for selection and further plant breeding. The result is a fruitful partnership and exchange of genetic materials and knowledge.
2 More milk from local goats
The Chakranagar region of Uttar Pradesh, India, is home to the Jamunapari breed of goat. These locally adapted goats, a large dairy breed with a good meat carcass, are able to survive in very arid and barren conditions. Introduction of new breeds in recent years has led to a decline in numbers of the pure-bred Jamunapari goats.
The Central Institute for Research on Goats in Makhdoom has established a herd of Jamunapari goats, as well as a village-based conservation and improvement programme. Farmers who maintain herds of Jamunapari goats are involved in all aspects of the conservation, breeding and improvement of the breed. The institute has found them enthusiastic about the programme and happy to assist with milk recording and other monitoring activities in exchange for veterinary and management advice on shelters and parasite and disease control. Research on breed improvement and evaluation continues. Survival of the Jamunapari depends on the combined efforts of scientists and farmers.
3 Sustainable forestry in Peru
The natural forest of the small community of Ramón Castilla was being overexploited for wood, posts and poles, rapidly depleting the native tree species Alnus jorullensis. Now members of the community are learning sustainable forestry management while practising in situ conservation of forest resources.
Helped by FAO and forestry extension workers, the community has established a small in situ conservation area of A. jorullensis, as well as a nursery to provide saplings for planting along the contour lines of fields. Combining tree planting with traditional farming has increased food production by improving soil fertility and protecting the soil as well as providing fuelwood. Sustainable management of the remaining natural stands of A. jorullensis, including judicious felling and harvesting of wood and wood products for day-to-day use, is also ensuring the continued survival of a valuable natural asset.