desertification in north darfur state4
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Desertification in North Darfur StateTRANSCRIPT
35
Desertification in North Darfur State Salih Ahmedai Abdalla, Faculty of Environmental Sciences and Natural
Resources
Al-Fashir University-Sudan
عبدا هلل يصالح احمدا
جامعة الفاشر – كلية علوم البيئة و الموارد الطبيعية
التصحر في والية شمال دارفور
مستخلص البحث
شألجااءش الن الهقاا يفالاالهمناا والية االالداا وال شبهااحبالواايف اللااالشي الاالش اا واليال اا الالالالالال
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ال0515ال-0519يبلتالذ بال ليللالم الشجلا فالشحملألي الاالش اا يفالال.المالال0510ال-0511
المال0555ماليال0551ماليشألعحشمال
اايف الش لئيياالال لتصااالالش تح ااعالاالدبشعاالالش ااألل الاالشتناا ر العليلاالالشألمااا بالألماا الش
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يد ااا يفالك يااالالش غيفااا بالش لااا الاللغاااا الش نيفااا بيالينااااحتالشحليحشنااا تاليبلل ااالالش بااالال يإبااا يفال
ال.اليشجمل ع تاليشهلجليفاليالنءي الش يك نالإ يالشتن ر الشجلنحبيلالي ه الشألي لاليشحللي الش قيفليل
تك هالالش تصالالةالبألالم اليضعالعأليفالبلشمجالب لالم ليع تالش ت ج الشحلكحميال
ماليش ليباليإع يفالالبل ال اءشمالش صا االش للباياليدبشعالالش نخيالاليشإلبوا اليالش تحعيالاليالعيا الالالالالالالال
ال.الم ليع تالش تن يلالش ل ايلالشتتك مللالي ص الشتي ا
Abstract
The climate of North Darfur State is semi-desert and desert to the
north. The rainfall in about 200-400 mm with a rainy season of 2 to
2.5 months. It had a population of 2.1 million according to 2003
census and the population growth rate is about 12% per year and the
population density from 3 persons /km2
in 1956 to 18 persons / km2 in
2003.
Farmers practiced cultivations of millet, sorghum, sesame and
groundnuts during the rainy season and they keep livestock.
Cultivation of crops reached areas receiving 150 mm and crop rotation
is reduced resulting in decrease of soil fertility and yields. The spread
of rain-fed cultivation farmers used to cut the trees often fired the bush
destroying most trees and seedlings. They used large amount of wood
33
for fuel, constructions, tools and fencing. Subsistence needs are
considered to be about 250 kg of cereals/person/year. Millet yields in
North Darfur State about 60 kg/fed during the period 1973-2004 and
for sorghum 111.6 kg/feddan during 1970-1990. Livestock number
about 40 million. Average annual deforestation rate was 77% between
2000 -2005 and Darfur has lost more than 30% of forests since
Sudan's independence and rapid deforestation is going.
The destruction of the vegetation through pearl millet cultivation,
overgrazing and clearing of woodlands led to the loosening of the
sandy soil and its exposure to the influence of strong winds. The
dominant processes are wind and water erosion. The amount of the
dust in air has increased. Sand accumulation is often regarded as the
actual desert encroachment because the newly formed dunes encroach
on settlements and fields.
1-Environmental setting
Greater Darfur consists of five states North, Central, East, South and
West Darfur. North Darfur State lies between latitudes 12º N and 20
º
N and longitudes 21º 52
¯ E and 27
º 54
¯ E and had a population of 2.1
million according to 2003 census. The climate of the state is semi-
desert (a typical Sahel). In the Sahel zone three divisions are
recognized. The sub-desert (200mm), the typical Sahel( 200-400) mm
with a rainy season of 2 to 2.5 months, and the Sahel of Sudanese
border (400-600) mm with a growing season of 3 months. The main
features of the climate are a short rainy and highly variable season,
between July and September with unpredictable droughts and 90% of
30
the rainfall falls between July and September. The key features, which
adversely affect agriculture, are the low and erratic rainfall. The
economy of the state is based on traditional rain-fed farming, animal
rearing and petty trading. The elevation of the state is about 600-900
m above sea level and the topography of the region is interspersed
with various hills and mountains. Jebel Marra which is located
between latitudes 12° 25 ′ N and 13°N and longitudes 24°10 ′ E and
24° 12 ′ E, constitutes a volcanic mountain range about 135 km long
and 80 km wide with maximum elevation of 3042 m and covering an
area of about 8000 km2 .
The region is situated in a transitional zone between the northern
Sudan savannah and desert vegetation. The vegetation consists of
annual grass and scattered bush steppe in the north, gradually merging
in the savannah with perennial grasses and scattered trees (White,
1983). The vegetation classes based on structural type are: Woody
grassland, with trees more widely spaced up to 15 m, and different
species includes many broad-leaved types, which contains species
such as Combretum , Terminalia, Baobab, anddifferent species of
Acacia. The main types of grasses are Aristida. Ergrostis and
Cenchrus. The trees are mostly including Acacia, Zizphus and
Commiphora spp., Acacia Senegal is regarded as the characteristic
tree in the sandy soils, in areas rainfall between 200 -450 mm, Aristida
sieberana is dominated in clay soils, acacia mellifera is common.
Semi-desert: on the margins of the desert, consist of Acacia,
39
Commiphora, Hymphaene ,Salvadora persica (Harrison and Jackson,
1958).
Soil surveys carried out by Hunting Technical Services (HTS,
1976) divided Darfur region into six main soil classes: desert soils,
stabilized dune sand, cracking clays, riverine soils, Nagga and
alternating non-cracking clay soils. The two main soils in North
Darfur State are the sandy soils and the dark clay soils. The sandy
soils are mainly stabilized sand dunes known as qoz lands. They are
deep and often uniform over vast areas forming the different dunes.
Some dunes are quite pronounced, while others are heavily eroded and
almost flat and having red, yellow and white. The dunes lie in one
main direction, like the recent ergs or they may have a circular form
without any specific orientation. They consist of 60% coarse fine sand
and less than 10% clay. Soils developed on the recent erg have a
coarser texture than those developed on materials deposited later.
Plants can satisfactorily grow there but those with shallow root
network dry up at the end of rains. Erosion by wind or water is high
where the vegetation has been consumed or destroyed by livestock
around watering places and nomads encampments. Large quantities of
water can infiltrate at the collection points, contributing to growth of
trees or feeding reservoirs. The landscape is generally flat and the
dune slope between 1-3 % in various directions. These soils have been
subjected to inappropriate management, leading to wind and water
erosion (Brown and Hall, 1991). This was followed by organic matter
and nutrient losses, which in turn affected soil physical, chemical and
31
thermal properties. The main causes of land degradation are
inappropriate land use, mainly unsustainable agricultural practices
such as clearing of agricultural lands, especially mechanized clearing,
over-grazing, fuel wood extraction, building of settlements and bush
burning. These wide spread effects on both cover and composition of
vegetation. The intensification of these events due to human and
ruminant's population has led to shortening of fallow periods, thereby
limiting the regenerative capacity of soil flora and fauna. Also, the
shortening of fallow periods under intensive cropping weakens the
natural ability of soil to recover its fertility leading to land
degradation, lower crop productivity and reduce income (Clunies-
Ross and Hildyard, 1992). The main on-site effect of land degradation
is the decline in yield which can amount to more than 50% or an
increased need for inputs to maintain yields (Olaitan and Lombin,
1984). Moreover, the addition of fertilizers alone cannot compensate
for all the nutrients lost when top soil is eroded (FAO, 1983).Where
degradation is serious the plots may either be abandoned temporarily
or permanently or converted to grazing land or left to shrubs. Yield
reduction due to soil erosion may range from2-40% with a mean loss
of 8.2%. If accelerated erosion continues unabated, yield reduction by
2020 may reach 16.7% (lal, 1995). Recent studies indicated that the
storms were 34 and 51 incidents for2002 and 2003 in Al-Fashir
(Ayoub,1999). Soil particles analysis showed that, soil samples of
Khartoum State were medium textured including 20 sandy clay loam
and 16 sandy loam, while North Darfur State were coarse textured
35
soil including15 sand,10 loamy sand and 6 sandy loam. For the wind
erodibility indices, the range for Khartoum State and North Darfur
State samples range from 0.0 to 259.3 and from 25 to 695 ton/ha,
respectively (Medani, 2004)
Farmers practiced cultivations of millet, sorghum, sesame and
groundnuts during the rainy season and they keep livestock. The
dominant grass species in the range land are panicum furgidum and
Aristida hordeocea. The northern parts of the state is poor in forage
trees and in the dry season supports only relatively small number of
animals. Trees such as Acacia ehrenbergions , Salvadosa persidea and
Acacia raddiana are very rare, scattered and they are small in size.
Dry season range land: good grazing is found and cover large areas
sometimes late until March. The common species are Commiphara
Africa, Aristida mutabililis and Aristida funiculate.
2- Land Degradation and desertification
Desertification is combinations of drought processes which result in
more or less irreversible of the vegetation cover leading to the
extension of new desert landscapes to areas which were formally not
desert. The increasing destruction has influence through reduction of
food production and loss of genetic resources of plants and animals.
Desertification can be defined as: "the land degradation in arid and
semi- arid and dry sub-humid areas resulting from various factors
including human activities and climatically variations (UNCCD,
2001) ".
01
Land degradation is the reduction of the current and potential
productive capacity of the land. Vegetation degradation is the
quantitative and /or qualitative reduction of the vegetation cover
resulting from various factors including human induced activities and
severe prolonged droughts under poor land resource management
Mustafa,2007). Despite adverse and fragile initial conditions of most
tropical soils, human activities significantly contribute to land
degradation, either directly or indirectly.
2-1 Causes of desertification
a--Climatic variation
Droughts have frequently happened as a natural disaster and
unavoidable phenomena in wide areas of the world. The rural poor in
dry areas will suffer the most from this phenomenon and will require a
range of coping strategies to help them adapt to changing climates.
Drought is an insidious hazard of nature and originates from a
deficiency of precipitation over an extended period of time, usually
one season or more. During the period 1961-2000, droughts of varying
in severity occurred in the state. This period witnessed two
widespread droughts during 1967-1973 and1980-1984. The same
period witnessed a series of droughts during the years1987, 1989
and1990.
In the semi-arid zone of sub-Saharan Africa, especially the rural
savannah zone, poverty and food insecurity are interlinked and
widespread and strongly linked to the natural resources endowment
(water, soils and vegetation). Land and water degradation, overgrazing
00
and slash burn agricultural production practices have led to significant
environment degradation and food shortages. The capacity of most
areas to combat desertification is limited, due to the widespread
poverty, recurring droughts, inequitable land distribution and the
dependence on rain-fed agricultural (Mc Cartly et al., 2001). In
comparison to all other regions of the world, the agricultural
productivity per unit of water (“crop per drop " ) in the semi-arid
zones is the lowest worldwide (Rockst-on, et al., 2004). The
increasing vulnerability of societies and ecosystems leads to a
downward spiral of ecological and social degradation and
consequently to an increase to disasters(Table1,Fig.1).
Table1. Long-term rainfall reduction in Darfur
Location Average annual rainfall (mm)
Average annual rainfall (mm)
Reduction (-)
(mm)
%
1946-1975 1976-2005
AlFashir 272.4 178.9 93.5 -34
Nyala 448.7 376.5 72.2 -16
AlGeneina 564.2 427.7 136.5 -24
09
Fig 1. Distribution of annual rainfall (10 years) in Al-Fashir during the period
1946-2000
A climate study was conducted in western Sudan using rainfall
and temperature data for the period 1961 – 1990 and modeled to
predict changes in temperature and rainfall from the baseline to the
years 2030 and 2060. The climate model results indicated a 0.5 to 1.5
C rise in the average annual temperature and an approximate 5% drop
in rainfall. The findings were then used to project the scale of
potential changes in crop yields for sorghum, millet and gum Arabic.
Sorghum production will drop by 70% from 495 Kg to 150
Kg/hectare. The model which focused on changes in the growing
season, predicted that in the state, the growing seasons would be
shorter and the percentage of failed harvests would increase.
0
50
100
150
200
250
300
350
1946-1955 1956-1965 1966-1975 1976-1985 1986-1995 1996-2005
Rain
fall
(m
m)
years
05
b- Human activities
i- Population growth
North Darfur State had a population of 1.3, 2.1 million according
to 1993 and 2008 census, respectively. In Darfur region statistics
indicated a regional population linear growth rate of 12% per annum,
from 3 persons /km2 in 1956 to 18 persons / km2 in 2003 ( Fadul,
2004).The displacement of the people from the north Darfur due to
desertification (Table 2). The population is concentrated in a belt
between 11◦ and 14◦ N. North of this belt, towards 16◦ N the
decreasing annual rainfall reduces the importance of agricultural
activities and nomadic pastoralism. The population consists of
different ethnic groups; some are specialized in crop cultivation,
others in cattle rearing and camel herders.
Table 2. Population growth in Darfur region during the period 1956-2003
Year Population (1000) Population density (person/ km2
1956 1080 3
1973 1340 4
1983 3500 10
1993 5600 15
2003 6480 18
ii - Crop cultivation
People practice cultivation of sorghum, millet, sesame and
groundnuts during the rainy season and they keep livestock.
00
Traditionally farmers practiced a type of rotating fallow agriculture
which left portion of the land with some ground cover. There is an
increase in encroachment of cultivation into pastoral area. Subsistence
needs are considered to be about 250 kg of cereals/person/year.
Decrease in yields and increase in population that mean more land
should be cultivated. Cultivation of crops reached areas receiving 150
mm and cop rotation is reduced resulting in decrease of soil fertility
and yields (Tble3, 4).
Pearl millet (Pennisetum glacum (L.) R.Br) is one of the most
drought resistant grains and appears to be more tolerant of sandy and
acidic soils. It is deep rooted and can use residual nitrogen,
phosphorus and potassium. Pearl millet needs a cultivation period of
about 100 days and seven favorably rainfalls. The border of relatively
dense pearl millet cultivation fields about 250 mm isohyets. This
border lies about 200 km north of the area of sufficient humidity for
cultivation. On sandy soil 500 mm isohyets seem to be an appropriate
border while on the clayey soil the 600 mm isohyets is more
reasonable (Ibrahim, 1986). For pearl millet cultivation, the peasant
cuts down all the trees and clears the land completely of all weeds ,
often uses fire killing most trees and seedlings and grasses to secure
every drop of water for the millet plants. Repeating these practices
leads to the ultimate destruction of the natural vegetation cover, which
enhances the deflation of the top soil. People consume large amount of
wood for fuel, construction, tools and fencing. Expanding population
and extensive rain-fed cultivation combined to bring under cultivation
03
more arable land in the state. A simulation of cropping boundaries for
the year 2050 implies that large areas at the margins of current arable
lands will no longer be suitable for cropping (Thornton,et al., 2002). It
was reported that about 65% of sub-Saharan Africa's populations in
rural areas are mostly dependent on rain–fed agriculture. Their need to
improve food security and livelihoods become a matter of utmost
importance and urgency. The current level of dependency on irrigated
land is very low (less than 2% of the cultivated land), therefore rain-
fed agriculture increasingly plays central role in sustaining rural
livelihoods and meeting food requirement.
Table 3.Millet production in North Darfur State during 1970 – 2005
Year
Area
cultivat
ed
(1000
fed)
Area
harvest
ed
(1000
fed)
Produ
ct
(1000
MTS)
Yield
(kg/fe
d)
year Area
cultivat
ed
(1000
fed)
Area
harvest
ed
(1000
fed)
Produ
ct
(1000
MTS)
Yield
(kg/fe
d)
1970/
71
480 360 62 583 1986/
87
1262 757 35 171
1971/
72
676 345 54 511 1987/
88
925 555 15 132
1972/
73
678 366 51 139 1988/
89
951 713 45 215
1973/
74
633 342 32 267 1989/
90
905 516 12 95
1974/
75
631 473 58 362 1990/
91
559 318 13 41
1975/
76
944 510 51 325 1991/
92
1290 662 58 88
1976/
77
845 507 53 387 1992/
93
1548 1032 82 215
1977/
78
1072 643 60 93 1993/
94
1720 542 36 66
00
1978/
79
1065 639 65 417 1994/
95
2400 1800 180 100
1979/
80
944 538 41 303 1995/
96
2074 1058 16 15
1980/
81
1003 602 66 445 1996/
97
1720 528 23 44
1981/
82
1003 602 73 384 1997/
98
2014 1037 75 72
1982/
83
1118 559 29 52 1998/
99
2200 1861 251 135
1983/
84
2110 654 46 70 1999/
00
1493 979 80 82
1984/
85
1748 542 25 46 03/20
04
2230 1050 83 79
1985/
86
1218 731 48 227 04/20
05
2380 1322 79 60
Source: Ministry of Agriculture and forestry- Khartoum – Sudan (2002)
Table 3.Sorghum production in North Darfur State during 1974 – 1990
Year Area cultivated
(1000 fed)
Product (1000 MTS)
Yield (kg/fed)
Year Area cultivated
(1000 fed)
Product (1000 MTS)
Yield (kg/fed)
1973/74 228 7 236 1982/83 65 10 154
1974/75 50 13 250 1983/84 42 1 30
1975/76 55 12 212 1984/85 45 1 22
1976/77 43 5 103 1985/86 115 21 180
1977/78 52 7 134 1986/87 100 7 70
1978/79 52 10 192 1987/88 175 5 30
1979/80 41 2 46 1988/89 210 37 175
1980/81 50 7 140 1989/90 200 8 40
1981/82 55 12 218 - - - -
Source: Ministry of Agriculture and forestry- Khartoum – Sudan (2002)
09
iii - Overgrazing
Livestock rearing is categorized into three types, pure nomadic
based largely on the herding of camels, sheep and goats, semi-
nomadic combing the herding of cattle and some sheep with a form of
cultivation in the seasonal wadis and sedentary system, where cattle
and small livestock are reared in close proximity to village. Seasonal
migration is often practiced by nomads and they face the problem of
overgrazing and the excessive use of water holes. The result is that the
surrounding grazing is destroyed and the grazing areas become bushy.
Methods of estimating livestock numbers showed there are large
numbers of animals in the state. Pastoral cattle herds show low milk
productivity and low slaughter off take as compared with other herds
and these breads are highly suitable for extreme climate. Marketing of
the cattle faces great difficulties including long transport distances,
price and processing.
iv- Deforestation
Forests and trees are the main sources of energy and provide
timber for roofing and building. The extensive benefits derived from
forests include grazing, hunting, shade, forest foods in the form of tree
leaves, wild fruits, nuts, tubers and herbs, tree bark for purposes, and
non- wood products such as honey and gum Arabic. This valuable
resource is threatened by deforestation driven principally by energy
needs and clearing land for cultivation. The types of forests and
vegetation found in state are: desert and semi- desert trees and shrubs
01
and low rainfall woodland savannah. Most trees in North Darfur State
grow in open to semi –closed woodland with numerous grasses and
shrubs. Desert vegetation is limited to xerophytes shrubs such as
Acacia ehrenbergion, Salvadosa preside, Acacia raddiana
,Commipharea fricana , Aristida mutabililis and Aristida funiculate.
Deforestation is an overall and effectively permanent reduction in
the extent of tree cover. The removal of trees has a range of very
negative impacts, including increased land and water resource
degradation, and the loss of the livelihoods from forest ecosystem
service. There are several causes of deforestation: fuel wood and
charcoal extraction; mechanized agriculture; traditional rain-fed and
shifting cultivation; drought and climate change; over browsing and
fires and conflict impacts. The reductions in rangelands has caused
problems for the pastoralist mobility but have kept their annual herd
migrations to well- defined routes. Their general pattern is to move
from north and south to optimize grazing conditions and minimizes
pest problems. Similar pattern of migration, though over shorter
distances, occurs in the hilly regions, where village’s areas are grazed
mainly in the dry season and high rangeland mainly in the wet season.
The major reduction in the amount, quality and accessibility of
grazing land is considered to be a root cause of conflict between
pastoralist and the village farmers.
c- Climate change
African dry lands are affected by climate change. It was confirmed
that most published climate change scenarios indicate temperature
05
increases for most of Africa, while expected rainfall trends vary
(IPCC, 2007). There is a general consensus that climate variability
will increase leading to an increase in drought and floods and to
growing uncertainty about the onset of the rainy season. Climate
change thus affects the hydrological cycle, water resources,
agriculture and ecosystem performance and services.
The climate variability in Sub-Sahara Africa has shown a marked
decline in rainfall leading to decrease in discharge of some
watercourses (Nissae et al . 2004) .In the second half of the last
century, mean annual temperatures in Africa rose approximately half a
centigrade with some areas worming faster than others . This gradual
heating means more warm spells (days) and fewer cold days across
the continent. IPCC (2007) reported that a warming in Africa may be
higher than the global average and that may be persisting throughout
all seasons. Further, it was reported that annual mean surface
temperatures are expected to increase between 3 -4 oC by 2009 which
is 1.5 times the average global temperatures rises. On regional
variations it was concluded that warming is likely to be greatest over
the interior of the semi-arid margins of the Sahara and central
southern Africa. In East Africa increasing temperatures due to the
climate change will increase rainfall by 5 -20% from December to
February, and decrease rainfall by5–10% from June to August by
2050 and Al-Fashir meteorological station showed the same trend.
The long- term (30 years) average precipitation for Al–Fashir has
declined from 300 mm per annum to approximately 200 mm during
91
the period1961-2000, while before 1953 the annual rainfall exceeded
400 mm (Table 1, Fig1).
2-2- Socioeconomic impact
The reduction in rainfall has turned million of hectares of already
marginal semi- desert grazing land into desert. The impact of climate change
is considered to be directly related to the conflict in the region and
desertification added significantly to the stress on the livelihoods. Fighting
in Darfur has occurred intermittently for at least thirty years. Until 2003, it
was mostly confined to series of tribal and local conflicts. The ongoing
conflict is characterized by a ' scorched earth' campaign carried out by
militias over large areas, resulting in a significant number of displacements
of people into camps for protection, food and water and over two million
people are displaced since the beginning of the war(UNEP/FAO/ICRAF
,2006).
3-Combating desertification
Desertification is the destruction of the biological potential
of the land and leads to deserts like conditions. The most identical
causes are human mismanagement of soil, water, energy. Land
degradation occurs due to overgrazing, farming marginal lands,
population growth and drought. Natural arid ecosystems are able to
withstand prolonged drought without significant loss and when rains
return, such community’s spring back into vigorous function.
Desertification/degradation reduce the productivity of the
land, which are exacerbated through non-sustainable use. Combating
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desertification aims to restore this loss through sustainable land use
systems that increase soil organic matter, prevent soil erosion,
improve soil structure, increase infiltration, decrease rain drop impact,
decrease runoff, promote salt-leaching and protect soil from the
accumulation of toxic substances. The general projects include
promoting public environmental awareness, policies, legislation and
land tenure, community services e.g. marketing, monitoring and
evaluation, food production and research and technology transfer.
Specific projects include reforestation, sand dune fixation, restocking
of gum arabic trees,firelines.village perimeters, increasing food
productivity, rainwater harvesting techniques and wildlife reserve
(Mustafa, 2008).
The range and water should be effectively owned by
definite groups. The range must be used in a rotational pattern using
different grazing techniques and impartation off by fire breaks and
marketing facilities should be provided. From estimation it was found
that fires usually remove 80 million tons of forage from dry savannah
range resources equivalent to 9 months diet of 25 million cattle.
Shortage of forage can be balanced especially in the low land
depressions and the natural water spreading areas where production of
forage exceeds the livestock consumption capacity for dry
periods(Glantz, 1977).
Water management includes water harvesting techniques e.g.
natural impervious surface, land alternation, chemical soil treatment,
utilization of periodic stream flows for water spreading, maintaining
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water where it falls (in situ),modifying the vegetation on water shed
areas to improve yields, erosion and evaporation
control(Abdalla,2008). The management of the state is to control
population growth, emigration and proper land use. The guides for
development should be based on a realistic acceptance of the
ecological factors: low rainfall, unpredictable recurrence of periodic
drought, uncertain and irregular production, low potential per unit
land area and unstable ecosystems (Goodall, et al.1979).
4-Discussion
Desertification results in the creep of desert like conditions into areas
where they should not climatologically exist. It is due to the increasing
pressure of man and his animals in unstable semi-arid regions.
Desertification is discontinuous whereas it may be more or less halted
during a series of heavy rainy seasons.
Biological recovery of degraded ecosystem should include increase of
biological activity, biomass, plant cover, organic matter and soil micro
and macro organisms. It is also includes higher soil fertility, better
water intake and lower evaporation and runoff. It attained through
natural and semi-natural conditions. Natural biological improvement
of ecosystems is achieved through protection from man and his
animals such as fenced areas where animals not be allowed to enter.
Natural ecosystems development allow to increase development of
producers and then consumers which leads to production of organic
matter and increases biological activity thereby improving soil
structure, permeability and water intake. Natural system is slower
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when the climate is more arid and it is excellent in enclosures
(Goodall,et al.1979). Semi-natural may be speeded up by artificial
measures such as pitting, counter terracing, over sowing, water
spreading techniques and fertilization. It also includes planting
drought resistant of woody species for fuel, sand dune stabilization,
wind breaks, shelter belts and reclamation of saline and alkaline land.
Conclusion
Desertification is partly manmade phenomenon aggravated by climate
circumstances and any measure for stopping loss of land productivity and to
increase degraded land productivity must nesserialy interfere with human
behavior and land use management. Natural recovery should include
increase of biological activity, biomass, plant cover, organic matter and soil
micro and macro organisms. Range must be used in a rotational pattern
using different grazing techniques and impartation of by fire breaks and
marketing facilities should be provided. Shortage of forage can be balanced
especially in the low land depressions and the natural water spreading areas
where production of forage exceeds the livestock consumption capacity for
dry periods.
Recommendation
It was suggested that in order to reduce desertification some steps
should be taken by the government. These steps will include reducing
the dependency of rural society on agricultural income, use of
advanced weather forecasting tools, cultivation of resistance crop
varieties, crop diversification and adaptation of new water harvesting
90
techniques especially use of supplementary irrigation systems. One
should differentiate between true climate deserts and the man made
deserts which occur in arid regions.
The strategy for the countries at risk is to use their natural
resources in a sustainable manner and to check population growth.
These should be on increase in projects concern with conservation of
ecosystems such as planting shelter belts on huge scale, range
management and water management (Goodall, et al.1979). Maximum
advantage can be gained by control of livestock levels, rain-fed
cultivation and soil cover is desirable to conserve soil nutrients which
enable the surface plant cover to spring back into a high productivity.
93
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