Dry and sub-humid lands are home to around two billion people, 35% of the global population, and encompass approximately 44% of the world’s cultivated systems. Dry and sub-humid lands also have great biological value and are the original source of many of the world’s food crops and livestock including wheat, barley and olives. The conservation and sustainable use of dry and sub-humid lands biodiversity is, therefore, central to livelihood development and poverty alleviation. In fact, 90% of people inhabiting dry and sub-humid lands live in developing countries.
The biological diversity of dry and sub-humid lands is of particular significance because it includes many unique biomes. Wetland areas in drylands, for instance, are often of crucial importance in supporting migratory bird species, as well as local species. Furthermore, because of the potentially harsh conditions of dry and sub-humid lands many species have developed unique adaptations. The Gemsbok of the Kalahari Desert, for example, can survive for weeks without drinking water, while the sociable weaver of southern Africa builds communal nests that can weigh up to 1,000 kg in order to maximize insulation from extreme temperatures.