Drylands Biodiversity

Source: Food and Agriculture Organization of the United Nations, 2013, Saadia Iqbal, You Think!, The World Bank,   "The Youth Guide to Biodiversity" 1st Edition (Chapter 6) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 6. Jaime Webbe, CBD. Verbatim.

Dry and subhumid lands, also known as drylands, cover about 47 percent of the Earth’s land surface and include everything from deserts to savannas to Mediterranean landscapes. Although drylands are commonly imagined to be barren, dead landscapes, they contain a number of important, well-adapted species.

The Serengeti grasslands in sub-Saharan Africa, for example, support an annual migration of approximately 1.3 million blue wildebeests, 200 000 plains zebra and 400 000 Thomson’s gazelles. The rocky, shrub-dominated Mediterranean Basin in Europe and North Africa, contains 11 700 endemic plant species that are unique to these areas.

Biodiversity in dry and subhumid lands is critical for human survival. For example, some of the world’s most important food crops originated  in drylands including wheat, barley and olives. Dryland biodiversity also provides genetic sources for one third of the plant-derived drugs available in the United States alone. Finally, the traditional knowledge associated with livelihoods in drylands, including from pastoral peoples, is important for sustainable development, a long-term process of enlarging people’s choices and freedom.

Unfortunately, the biodiversity of dry and subhumid lands is facing a number of threats from human activities. Between six and 12 million square kilometres of dry and subhumid lands are affected by desertification – that is, the degradation of land to such an extent that production is reduced. Already at least 2 311 species are threatened or endangered in drylands, while at least 15 species have disappeared completely from the wild. 

This trend shows no sign of reversing as drylands are among the most vulnerable regions to the negative impacts of climate change. In sub-Saharan Africa, for example, between 25 and 40 percent of mammals in national parks may become Endangered while as many as two percent of the species currently classified as Critically Endangered may become Extinct as a result of climate change.

Given the challenges faced by the biodiversity of dry and subhumid lands, it is important to take action now. We need to learn more about these important regions and the value of their biodiversity in providing critical ecosystem services. We need to involve native or indigenous peoples living in drylands in decision-making. We need to address the global challenges of climate change and desertification.