Sustainable Use of Biodiversity in Drylands

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Arid, semi-arid and sub-humid areas encompass a wide range of natural habitats, including grasslands, savanna, barren deserts, scrublands, woodlands and forests. These lands possess a rich array of biodiversity that is unique in its ability to survive in and adapt to dry conditions.

Biodiversity is vital for maintaining the health of dryland ecosystems. The loss of a few species may reduce ecosystem resilience significantly, with dire consequences for human livelihoods. A diverse array of domesticated and wild plant species provide people with food, livestock and wildlife with feed as well as many other goods and services.

Equally valuable is the rich genetic wealth tied up in domesticated animals. The estimated 4,000 animal breeds known around the world are gaining importance in the fight against poverty, hunger and disease. But some 30 percent of the world's domesticated animals, most of which are found in the tropics and have never been developed, now face the prospect of extinction.

Pastoral livestock production can easily coexist with wildlife. But as crop production is extended into grasslands, wildlife populations decline dramatically. So, a major challenge in areas such as the Mara-Serengeti ecosystem in southwestern Kenya and northern Tanzania is to manage conflicts between cropping, pastoral livestock production and wildlife-based tourism and enhance the benefits from these competing activities.

Biodiversity contributes vitally to agriculture in drylands, as it does in other ecosystems. The wild relatives of staple foods often contain genes that are useful for crop improvement. And the cover provided by diverse vegetation is critical for soil conservation and for the regulation of rainfall infiltration, surface runoff and local climates. Through activities such as overgrazing, deforestation and the expansion of cultivated land, agriculture may contribute to biodiversity loss, which helps trigger desertification. Once this process is underway, it not only threatens dryland agriculture and pastoralism but also leads to further erosion of biodiversity.

To promote the protection and sustainable use of this valuable resource, scientists have opted in recent years for a research approach that addresses the challenges of agriculture and the management of biodiversity and other natural resources in an integrated fashion. This approach aims to promote diversified rural livelihoods in drylands, based on sustainable management of genetic resources.

Selected Highlights from Research for Dryland Development

Seed fairs to promote plant genetic diversity: A project carried out by the International Plant Genetic Resources Institute (IPGRI) with NGOs and other partners in Mali and Zimbabwe is demonstrating how dryland farmers manage and conserve their plant genetic resources and how to spread best practices. It is also showing how farmers can use these resources to cope with the effects of drought and desertification and improve their livelihoods.

One valuable technique, pioneered in eastern Africa by NGOs working with several CGIAR Centers, involves "seed fairs" organized by rural communities. They offer farmers an opportunity to share information and experience and to display and swap samples of the crops and other plants they grow. The emphasis is on variety, not perfection or abundance, and prizes are awarded for the most diverse displays rather than for the finest crops. International aid agencies have created programs that provide farmers with vouchers for buying seed at these fairs. This measure reinforces local seed systems rather than undermining them, as did the previous practice of introducing imported seed in connection with disaster relief.

Managing trees in agricultural landscapes: Trees are scarce but important in drylands. They capture and recycle nutrients and water, stabilize hillsides and sand dunes, and provide diverse products that are important for people and animals.

The semi-arid Parklands of West Africa provide one example of a traditional system that integrates trees, crops and livestock. Spanning the whole of the Sahel, the Parklands sustain more than 40 million people but are believed to be undergoing rapid degradation in many areas.