Degradation of Arid Lands: Desertification

1
Degradation of Arid Lands Desertification
2
Man strides over the earth and deserts follow in
his footprints. Ancient Proverb
3
Definition A process of environmental
degradation by which productive land is made
non-productive and desert-like
4
(No Transcript)
5
The white man has reversed the slow work of
nature that had been going on for millenia. Thus
have come deserts, so long checked and held in
restraint, to break their bonds. At every step
the girdle of green about the desert has been
forced to give way and the desert itself allowed
to expand. If man destroys the balance and
equilibrium demanded by nature, he must take the
consequences. Paul Sears, 1935
6
Statistics Currently 35 of the worlds land
surface is at risk...each year 21 million
hectares is reduced to near complete
uselessness. -United Nations Environmental
Program (UNEP)
7
(No Transcript)
8
The Sahara Desert continues to creep southward,
claiming an area the size of New York State every
decade. Smith, 1986
9
Desertificationis probably the greatest single
environmental threat to the future of well-being
of the earth (Hogel 1979)
10
It fell across our city like a curtain of black
rolled down We thought it was our judgment, we
thought it was our doom. - Woody Guthrie
11
Hypothesis Population growth is a major
determinant of technological change in
agriculture, leading to innovation, improved land
care and intensification.
12

• Ecological Features of Arid Lands
• 1. Climate prolonged dry season, punctuated by
  brief, highly-productive rainy season
• high annual variation in rainfall
• 2. Natural vegetation perennial shrubs and
  grasses
• Natural food chain large herbivores with complex
  migratory routes
• 4. Tradition human subsistence nomadic
  pastoralists

13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
Reij, C. G. Tappan and A. Belemvire. 2005.
Changing land management practices and vegetation
on the Central Plateau of Burkina Faso
(1968-2002). Journal of Arid Environments
63642-659.
21
Tiffen, M., M. Mortimore and F. Gichuki. 1994.
More People, Less Erosion Environmental Recovery
in Kenya. John Wiley Sons, NY
22
Evaluation Desertification is probably the
greatest single environmental threat to the
future well-being of the Earth Hogel, 1979
23
The Machakos Reserve is an appalling example of a
large area of land which has been subjected to
uncoordinated and practically uncontrolled
development by natives whose multiplication and
the increase of whose stock has been permitted,
free from the checks of war and largely from
those of disease, under benevolent British rule.
- Colin Maher, 1937
24
Elements of a new Green Revolution development
of a local or regional cash economy development
of infrastructure especially transport, water
and sanitation cooperatives storage and
marketing small-scale credit services macroecono
mics national debts and structural
adjustment research to improve traditional
cropping systems or to transform
them education changes in land tenure land
reform, titling expanded markets for
sustainably-grown crops
25
Volunteers needed Look what's happenin' up the
street, got a revolution! Hey all you neighbors
down the street, got a revolution. Ain't it
amazin'all the people I meet, got a
revolution One generation got old, one generation
got sold This generation's got no destination to
hold And now it's time for you and me, got a
revolution Hey come on now we're marchin' to the
sea, got a revolution Oh who are all these
people, yeah who are we? Well, we are volunteers
of America. Jefferson Airplane (1969)