A new report, titled "Global Drylands: A UN system-wide response," sets out for the first time a coherent strategy by the UN to address the special needs of drylands from the perspective of the environment and human settlements.
Dryland ecosystems cover an estimated 40 percent of the world’s land area and support around two billion people, 90 percent of whom live in developing countries. With 10 percent of the world’s dryland ecosystems already degraded, putting at risk the social and economic well-being of millions of people, United Nations agencies have agreed to step up their efforts to protect and revitalise drylands. Global Drylands: A UN system-wide response (www.unemg.org) sets out for the first time a coherent strategy by the United Nations to address the special needs of drylands from the perspective of the environment and human settlements.
As drylands are so extensive, diverse and unique, the survival of their ecosystems and species matters to the world as a whole. Dryland biodiversity is important, not least for adaptation to future climate change, and includes a relatively high number of endemic species: plants and animals uniquely adapted to the variable and extreme conditions of these areas, including diverse habitats, such as deserts, forests and woodlands, savannahs and steppes, wetlands, ponds, and lakes and rivers. Dryland biodiversity faces high risks from habitat change, overuse, the introduction of invasive alien species and other anthropogenic pressures.
The major characteristic of most dryland ecosystems is instability, yet they are incredibly resilient. Plant biomass in rangelands is driven by annual rainfall rather than by stocking pressure: when pasture fails, the animals die or migrate. However, seed banks in the soil ensure that vegetation recovers, although not necessarily with the same species composition. This capacity of the ecosystem to maintain its functional integrity while adjusting to variable drivers has led to drylands being described in ecological terms as “unstable but resilient.”
There is a growing recognition of the need to conserve dryland biodiversity, not only for its own sake, but also because biodiversity helps provide ecosystem services on which people depend. In the face of hardship, variability and risk, many dryland populations have developed resilience based on historic and current adaptive knowledge and skills. Local people often have a profound understanding of dryland ecosystems. They frequently use a wide range of wild species as part of their livelihoods, and their livestock and crops are the products of long periods of selective breeding for adaptation to local conditions.
Protected areas are a key tool to conserve dryland ecosystems and the benefits they provide to people; however, at present drylands are relatively less well protected than other terrestrial ecosystems. A new analysis conducted for the global drylands report shows that protected areas cover approximately 9 percent (or 5.4 million square kilometers) of the world’s drylands, compared to 12.9 percent of the world’s total land area. Still, protected drylands make up 3.6 percent of the world’s land area, or 31.1 percent of the world’s protected land area.
Global Drylands: A UN system-wide response sets out a common vision and agenda for UN-wide action on drylands management and the UN’s role in addressing climate change and food security through a positive development and investment approach. With the UN’s commitment to dryland ecosystems, we should anticipate and expect more attention to the biodiversity found in these important ecosystems, and further analysis of the extent to which drylands biodiversity is protected.