Rain, floods, or drought? Africa, north and south of the Sahara
Throughout much of Africa the plowing and monocropping on fragile soils of
colonial times continued after independence.10
National governments viewed common tenure claims as impediments to getting
access to more agricultural land for growing populations. But when traditional
common forests and lands managed by village elders were broken up, they were
not replaced by alternate tenure arrangements and the state could not protect
the areas. Neither individuals nor communities owned the land or forests, so
there were no clearly defined or direct consequences of misuse.11
So the lands were misused.
Changes in land use can rapidly lower soil quality, and intensive cultivation
can deplete soil nutrients. Deforestation can cause erosion, washing away the
layers of soil most suitable for farming. Two patterns are typical in Africa
(and the world):
-
Growing populations convert higher quality pasture land to grow cash crops.
Herders lose the better grazing land, their security against drought. Migratory
movements for herders are reduced, lower quality land is more intensively
grazed, and overgrazing leads to degradation.
-
Poor subsistence farmers have to reduce fallow periods to feed growing
families. The reduction in fallow increases vulnerability to drought and
without sufficient inputs, depletes soil nutrients. Degradation and soil
erosion get worse.
More people and animals are concentrated on semi-arid and arid lands that can
sustain cultivation or more intensive grazing only when rainfall is higher than
normal. In the Sahel favorable rainfall from the 1950s to the mid-1960s
attracted more people. Rainfall reverted to normal low levels after 1970 (figure
4.3), and by 1974 an estimated 250,000 people had died along with
nearly all their cattle, sheep, and goats. Some 7 million people had to rely on
emergency food aid. The devastation prompted the United Nations to call a
special conference on
desertification in 1977 in Nairobi, Kenya.
The possibility that the Sahel could enter another period of favorable rainfall
poses the risk of repeating the same tragedy-as poor people are drawn back to
the land. Scientists do not have enough information about the effect of
climatic disturbances on the resilience and long-term viability of dryland
ecosystems; nor do they know the human and natural stress that these ecosystems
can handle.12
One difficulty in distinguishing between human and natural causes is the lack
of data on the extent of grasslands before human disturbance and the loss over
time.
The Intergovernmental
Panel on Climate Change (IPCC) reports that Africa is highly vulnerable
to climate change.13
Although the equatorial region and coastal areas are humid, the rest of the
continent is dry subhumid to arid. Global warming will reduce soil moisture in
subhumid zones and reduce runoff. Already, water storage has been reduced to
critical levels in some lakes and major dams, with adverse repercussion for
industrial activity and agricultural irrigation. Given the diversity of
constraints, Africa faces daunting challenges in adapting to the effects of
climate change (chapter 8).
The poor quality of soils is another constraining environmental factor.
Phosphorus deficiency, low organic content, and low water infiltration and
retention capacity on much of African soil have been limiting factors in
agriculture. Unlike climate variability, this problem can be addressed: soil
quality can be augmented through careful management and soil nutrient
supplementation. More difficult to address are the recurrent droughts (box
4.2).
Box 4.2
Traditional knowledge and voice: sustaining livelihoods on the grasslands of the
Sahel
Traditional survival know-how in Nigeria, grass-roots management efforts in
Burkina Faso, and high-efficiency rangeland management in Mali all illustrate
important livelihood strategies in the Sahel.
Seasonal migration and hedging techniques in Nigeria
In Nigeria, as in much of the Sahel, traditional social and institutional
mechanisms have allowed pastoralists to adapt to fluctuations in rainfall and
other natural changes.* Dryland people migrate in response to scarcity and
environmental change. For some, migration is seasonal, as between the dry and
humid areas of Nigeria. After the short rainy season Fulani pastoralists
migrate south to graze livestock and avoid the tsetse. On their return, they
bring back root crops grown in the south. Other arid land farmers and
pastoralists recognize the value of diversity in their hedging strategies
against environmental variability and water scarcity. They plant a variety of
crops adapted to different stresses and graze a mix of animals. These
strategies help people manage risks by understanding the resilience that
biodiversity contributes to dryland ecosystems.
Inclusion and grass-roots development in Burkina Faso
The communities inhabiting the Sahel are poor, and erratic weather patterns
make them just a growing season away from destitution. Providing for basic
health, education, and food security under such vulnerable conditions remains
very difficult. Service-asset management organizations are development
committees formed to manage local infrastructure assets and indigenous
associations that collaboratively manage resources such as land, forests,
water, livestock, wildlife, and some village production activities.** They
scale up the internal organization of villages and provinces by implementing a
culturally coherent strategy that balances equity and enhances productivity,
using mechanisms for inclusion, equity expansion, and compensation. Water
committees, for example, make decisions that ensure that a maximum number of
working boreholes or water ponds are within walking distance of the community
during the dry season, with adequate backups. (See also
box 5.5 on zais.)
There is hope that locally based rural organizations could make a difference in
coping with the climate problems and service delivery. Local institutions in
Burkina Faso start with equity and solidarity and aim for growth and
development. They are reducing poverty with little or no outside assistance.
Mali's high-efficiency traditional pastoral systems
Earlier research depicted traditional pastoral systems of the arid tropical
areas as inefficient. More recent findings highlight the efficiency of those
systems in using their resources.*** A pioneering study in Mali showed that the
mobile pastoral system produced 1.5 to 8 times more protein per hectare in meat
and milk than beef cattle systems under similar climatic conditions in the
United States and Australia, with essentially zero input of fossil fuel. The
more settled, sedentary systems in Mali were less efficient. Later work in
Botswana and other countries confirmed these indications of higher biological
efficiency.
The findings shift thinking about rangeland management under the highly
variable climatic conditions of arid tropical regions. Under those
"nonequilibrium" systems livestock producers need to be able to "track"
available forage or find new grazing areas for their animals, which usually
requires access to large areas that encompass a diverse range of landscape
niches. This calls for mobility and flexibility that enable rapid destocking in
times of drought and restocking when the rains reappear.
Source: * See
Niamir-Fuller (1998); **
See Donnely-Roark, Ouedraogo, and Ye (2001); ***
See Breman and Wit (1983);
Behnke, Scoones, and Kerven (1993)
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