Vital GEO Graphics

( Populus alba ). Credit: Yao Jianming

Sand encroachment and land reclamation in China. Top, 2000; Bottom, 2004 planted with Xinjiang poplar ( Populus alba ). Credit: Yao Jianming

When land degradation processes, acting lo- cally, combine to affect large areas in drylands, desertification occurs. Some 2 billion people depend on drylands, 90 per cent of them in developing countries. Six million km 2 of drylands bear a legacy of land degradation. It is hard to deal with the problem, because of cyclical swings in rainfall, land tenure that is no longer well adjusted to the environment, and because of other driving forces. The international response to desertification has been led since 1994 by UN Convention to Com- bat Desertification (UNCCD), which has been ratified by 191 countries. 79 countries have drawn up National action programmes, there are 9 sub-regional programmes targeting trans-bound- ary issues and 3 regional thematic networks. Forests provide a range of valuable ecosystem services, such as soil and water protection, absorption of pollution, and climate regulation through carbon fixation. Forest ecosystems are also a great source of biodiversity.

D ownload G raphic 2

Source: GEO Data Portal, compiled from FAO 2005

Total forest area by region

11

million km 2

1990 2000 2005

10 9 8 7 6 5 4 3

1 2 0

North America

West Asia

Africa

Asia and the Pacific

Europe

Latin America and the Caribbean

31 ECOSYST EM MANAGEMENT