Geoscience Reference
In-Depth Information
the complex issues involved. The negotiations prospered, and eighty-seven nations
signed the Desertification Convention in Paris on 14-15 October 1994, a remarkable
achievement given the diversity of opinions involved (Kassas,
1995b
; Williams et al.,
1995
; Chasek,
1997
). The full and rather cumbersome title of this convention is the
United Nations Convention to Combat Desertification in those countries experiencing
serious drought and/or desertification, particularly in Africa
. We have discussed the
reasons for the emphasis on Africa and for the mention of drought in the Introduction
to this chapter. A major goal of the Desertification Convention was to encourage indi-
vidual countries to prepare their own action plans to combat desertification. (Use of
the bellicose verb 'to combat' seems, in the author's view, to give the wrong emphasis.
Prevention and management would be more appropriate terms).
More specific discussion of some practical measures to alleviate desertification and
of some key principles upon which to achieve sustainable use of desert environments
is best deferred until
Chapter 26
, after we have considered current climatic trends and
possible future changes. However, some general comments can still be made.
The spread of apparently unpalatable and 'useless' weeds into areas of previously
good grazing is not always an ecological disaster. Desert plant ecologists have long
been concerned with the impact of grazing on species diversity. In an elegant study
of the role of the spiny cactus
Opuntia polycantha
as a plant refuge in grazed,
short-grass, steppe-plant communities in North America, Rebollo et al. (
2002
) found
greater species diversity among the clumps of cactus than away from those plants,
which means that a spiny cactus that some might consider a weed in fact plays a useful
role in maintaining species diversity.
The success or otherwise of the many measures designed to reduce or prevent deser-
tification processes is seldom publicised, so it is often hard to determine the degree
of success of prevention and rehabilitation strategies. Any cost-benefit evaluation of
successful projects should take into account the fundamental principles of long-term,
ecologically sustainable development rather than focussing solely on short-term and
purely economic criteria.
Given the lack of primary meteorological, agrometeorological and hydrological
data for many of the drier regions of Africa, Asia and South America, it would be use-
ful to establish regional climate monitoring stations in those areas where the human
population is likely to be most vulnerable to probable future changes in climatic vari-
ability. Recognising the need for the enhanced provision of information governing
more sustainable forms of land use, greater efforts should be made to provide inform-
ation in an accessible and useable form to local farming and pastoral communities
(Williams and Balling,
1996
; Barakat and Hegazy,
1997
; Imeson,
2012
). The regional
centres just mentioned could be appropriate means of providing such information
to local communities. There are existing models from North America and Australia
that could be adapted to perform this role.
