MANAGING
FRAGILE ECOSYSTEMS: COMBATING DESERTIFICATION AND DROUGHT
12.1.
Fragile ecosystems are important ecosystems, with unique features and
resources.
Fragile
ecosystems include deserts, semiarid lands, mountains, wetlands, small islands
and certain coastal areas. Most of these ecosystems are regional in scope, as
they transcend national boundaries. This chapter addresses land resource issues
in deserts, as well as arid, semiarid and dry sub-humid areas. Sustainable
mountain development is addressed in chapter 13; small islands and coastal
areas are discussed in chapter 17.
12.2.
Desertification is land degradation in arid, semi arid and dry sub-humid areas
resulting from various factors, including climatic variations and human
activities. Desertification affects about one sixth of the world's population,
70 per cent of all drylands, amounting to 3.6 billion hectares, and one quarter
of the total land area of the world. The most obvious impact of
desertification, in addition to widespread poverty, is the degradation of 3.3
billion hectares of the total area of rangeland,constituting
73 per cent of the rangeland with a low potential for human and animal carrying
capacity; decline in soil fertility and soil structure on about 47 per cent of
the dryland areas constituting marginal rainfed cropland; and the degradation
of irrigated cropland, amounting to 30 per cent of the dryland areas with a
high population density and agricultural potential.
