沙漠研究 22-1, 9 -12 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－

To Combat a Negative Heritage of Combating Desertification:
Developing Comprehensive Measures to Control the Alien Invasive Species
Mesquite(Propopis juliflora) in Sudan
Hiroshi NAWATA*1)
Abstract: In the 1980s, mesquite (Prosopis juliflora) was considered an ideal anti-desertification tree due to its high capacity tostabilize sand dunes, survive inhospitable environments, and provide fuel, timber, fodder, and edible pods. However, once planted,
the mesquite seedlings failed to take root on sand dunes, but rather, became well established in oases, where they contributed to thelowering of the water table and suppression of native vegetation. The invasion of mesquite not only changed the regional ecosystem,
but has also caused livelihood degradation of local communities. The author seeks to learn from “mistakes” made unintentionally byscientists, administrators and NGO workers and go beyond criticism in order to continue doing the high quality scientific research.
An improvement of the negative legacies left from ineffective anti-desertification measures and the development of comprehensive
procedures to control the alien invasive species mesquite in necessary. Scientists from universities, research institutions, NGOmembers, consulting firms, developmental organizations and local people must work together, pooling together the best knowledge
available to build an effective mesquite management plan.
Key Words: Mesquite management, Multi-disciplinary project, Negative heritage of combating desertification

1. Introduction: The mesquite issue
1.1. Is mesquite the most promising and suitable species forafforestation, or a serious invader and a noxious weed?
The genera Prosopis and Acacia are some of the mostwidespread and important trees species found in the arid andsemi-arid zones of the tropical and sub-tropical world.
Mesquites (Prosopis spp.) are ever green leguminous trees orshrubs. There are 44 species, in the genus, of which 40 are
native to the Americas. Of the remaining four species, P.
Africana is indigenous to Africa and P. kodziana, P. farcta andP. cineraria are native to the Middle East and Pakistan(Burkart, 1976; Fagg and Stewart, 1994; Pasiecznik, 2001;
Pasiecznik et al., 2004).
In the 1980s, international organizations promoted theplanting of mesquites (Prosopis spp.) in Africa and West Asia
(Habit, 1988; Pasiecznik, 2001). However, mesquites proved
to be invasive, causing the alteration of the regional ecosystems
along with the degradation of livelihoods within the localcommunities (Mqangi and Swallow, 2005; Nawata, 2002a,2002b, 2009).
Today, the International Union forConservation of Nature (IUCN) lists mesquite as “100 of theWorld’s Worst Invasive Alien Species”.
Previously, mesquites were thought to be ideal trees inpreventing desertification because they were believed to beeffective in stabilizing sand dunes, surviving inhospitableenvironments, and providing fuel, timber, fodder, and edible
pods (Abdel Garbar, 1988; Pasiecznik, 2001). The seeds areadapted for endozoochory and are spread, encapsulated inanimal droppings to new sites over long distances. Mesquite
pods are also transported by floodwaters and runoff. Theirfast-growing root system and unpalatable foliage increase theseedling survival rate and competitiveness, particularly inheavily grazed and uncultivated fallow lands. However,studies have shown the mesquite seedlings’ preferred
establishment not on sand dunes, but in oasis, where they
contribute to lowered water tables and suppression of native
vegetation changing the productivity of dry lands (Babiker,2006; Moll and Gubb, 1989).
1.2. Situation in Sudan
Prosopis was introduced into Shambat in Khartoum,Sudan by R. E. Massey from the Egyptian Department ofAgriculture at Giza and from South Africa both in 1917
(Broun and Massey, 1929). The identity of the prevalent
species in Sudan is controversial. The species, whenintroduced, was claimed to be P. juliflora (Broun and Massey,1929), later, identified as P. chilensis (Wunder, 1966), which
was confirmed by Abdel Bari (1986), but refuted by Elfadl(1997) who ascertained the species as P. juliflora. Bukhari(1997) concluded from his cytological studies that P. chilensisand P. glandulosa var. torreyana are the possible progenitorsof Prosopis in Sudan. While it is still debated whether or not* Corresponding Author: nawata@chikyu.ac.jp
1) Research Institute for Humanity and Nature, 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047, Japan

it was P. chilensis or some other hybrid that was first
introduced into Sudan, it is generally accepted that whatever
the initial introduction may have been, the subsequent
introduction of P. juliflora from an unknown source now thedominates as the ‘common mesquite’ (Pasiecznik, 2001).
Mesquite is now considered a noxious weed in Sudan (Elhouri, 1986). It has invaded both natural and artificiallymanaged habitats, including watercourses, floodplains,
highways, degraded abandoned land and irrigated areas. The
weed is more of a problem within central, northern and easternSudan. Mesquite infestations covers over 230,000 hectares,
with the greatest degree of infestation found in eastern Sudan(>90%) (Babiker, 2006).
Realizing the seriousness of the problem, the Sudanese
government stopped planting mesquite in the 1990s and began
programs to eradicate mesquite, using both mechanical andmanual methods to uproot the trees (Harris et al., 1998;
SWITCH 2006). In New Halfa (where irrigated agriculture isprevalent), more than 88,000 hectares were infested bymesquite, and eradication costs were estimated at US$ 7.4
million in 2006. Eradication efforts are ongoing, however,scientists are stressing the need for a more integrated
management system in regard to this plant (Babiker, 2006).

2. Understanding the issues at the village level: A casestudy from the Red Sea coast of Sudan
2.1. A case study on a pastoral system and sustainable use of
biological resources of the Beja on the Red Sea coast in Sudan
The Author first became conscious of the mesquite
problem in 1993, when conducting an intensive fieldwork
survey while staying at a village along the Red Sea coast for
more than one year.
The survey looked at theinterrelationships between human activities and naturalenvironments viewed from cultural anthropology and social
ecology perspectives, focusing on pastoral systems, indigenous
knowledge, resource management, and local development,with a particular emphasis on sustainable use of biologicalresources as an adaptive mechanism of the Beja tribe along theSudanese Red Sea coast (Nawata, 2001, 2002a, 2002b, 2004).
Mesquite is found in shurblands at which the surface runoff
of seasonal streams, called wadi, terminates (Nawata, 2002b).
Villagers say that mesquite was planted by the Germans before
1980 to prevent sand dune migration and to protect village
from the wind, however, records show that they were probably
planted through the plantation program initiated by theInternational Development Research Center of Canada, in1976 (Abdel Garbar, 1988). According to the villagers,
planting the mesquite caused the sand dunes to grow several
meters high, for the plants acted as a trap for the sand.

Mesquite, however, also offered shade for the livestock to rest
under after drinking from the wells along the wadi. Some ofvillagers gather fallen pods in bags to carry back to feed theirgoats and donkeys. Children enjoy sucking on the pods fortheir high sugar contents. Regardless, the villagers do notthink highly of this exotic plant.
2.2. Local people’s accurate observation on mesquite problem
The local people with their traditional knowledge, havebeen living with the unstable and complex natural systems fora long time. For example, saline shallow wells are used forlivestock, particularly camels. Pastoralists used camels as anintermediary to enable the use of poor quality water resources
through drinking the camel’s milk. Camels feed on a wide
range of plant, including half-shrub halophytes and mangroves(Nawata, 2001, 2002a, 2002b, 2004). However, plantation ofexotic species mesquite at inappropriate places forced thepeople to a direction of linear development. This wasoutsider’s inappropriate technologies with shallow scientificunderstanding.
Local people are great and accurate observers. For
example, Mr. Mahmoud Othman saw that the cattle spreadmesquite seeds in their droppings, and also those who that feedon the mesquite pods had higher rate of mortality during
drought years. Several efforts were made by the locals tocontrol mesquite, by manual cutting, but rapid regeneration of
the plant ensued. Moreover, the local people emphasized thatit has become increasingly difficult to obtain drinking waterfrom their wells, which are experiencing a rapid andcontinuous drop in water level. The accuracy of theobservations made by locals were cross checked and later
confirmed by scientists (See previous chapter for details).
The author was once asked by Mr. Mahmud, “Mr. Nawata,
can you do anything for us?” At that time, there was not muchthat could be done. However, the problem persists and it is
not too late to tackle this issue. This led the author toorganize a multidisciplinary scientific research team. It istruly hoped that fruitful research will result in helping the local
people of Sudan to combat livelihood degradation by long termsolutions that can be immediately implemented at village level.

3. Organizing multidisciplinary scientific research teams
3.1. Breaking off from the existing framework of scientificunderstanding and the deadlock of social problems
The current situation suggests that we must break from theexisting framework of scientific understanding and thedeadlock of social systems. Solutions to the mesquite issues
must be based on the establishment of a direct relationshipbetween Japanese and international scientists and the common

people of Arab societies. It is only through such efforts
through which we can come up with both academicallyrigorous and socially sensitive solutions.
Existing scientific and social frameworks have often failed
to prevent new outbreaks of environmental problems. These
failures reflect several intrinsic issues within the academicworld. First, particularly in Japan, almost no collaboration
has existed between social scientists who study Middle Easternreligion, society, culture, history, politics, and economics andnatural scientists developing technologies applicable to arid
lands. Second, few connections have been establishedbetween scientists working at universities and institutions,
NGO workers, consultants, and project managers ofinternational organizations and development institutions.
Third, environmental impact assessments have provided little
opportunities for local people in the Middle East to participate
in social decision making processes.
Therefore, a multidisciplinary study with the involvementof multiple stakeholders will be designed and implemented toestablish comprehensive measures to control alien invasive
species by providing methods to cope with specific global
environmental issues (Nawata, 2010).
3.2. Applying scientific research results to a development
project
On 27 November 2008, the Research Institute for
Humanity and Nature (RIHN) and the Sudan University of
Science and Technology (SUST) agreed on a joint
Memorandum of Understanding and Implementation
Agreement to collaborate on a RIHN project titled, “A Study of
Human Subsistence Ecosystems in Arab Societies: To Combat
Livelihood Degradation for the Post-oil Era,” led by Hiroshi
Nawata. The main objective of the joint research project is todevelop comprehensive measures to control the alien invasivespecies mesquite (Prosopis spp.). Fifteen related topics will beinvestigated as part of the alien invasive species control project.
The Japanese-Sudanese interdisciplinary research teams
are developing comprehensive measures to control thisinvasive species. Hydrologists, plant physiologists, weedscientists, remote-sensing specialists, range managers,
agricultural economists, nutrient physiologists, and cultural
anthropologists are working together doing the field surveys onriverbanks, wadi beds, seashores and mountainsides in arid tosemi-arid areas of Sudan.
Scientific research results from the RIHN project’s weed
control team now is being applied to the Japan International
Cooperation Agency (JICA) development project “Capacity
Development Project for the Provision of Services of Basic
Human Needs in Kassala” (2011-2013).

4. Discussion
4.1. Combating a negative heritage of anti-desertification:
focusing on traditional knowledge
Recently, researchers and administrators have recognizedthat they have only a basic understanding of how local peoples
live in drylands. They have begun to identify the effects ofinappropriate policies and inappropriate technologies imported
from other regions, which have been the result of the dominant
top-down approach to problem solving (Nawata, 2009).
“Many detailed investigations have been undertaken todefine a set of practical solutions to this complicated problem.
It was once assumed that the transfer of technology, such aslarge-scale irrigation schemes, and the implementation ofrigorous national or regional policies, such as settlement ofpastoralists, might offer an ideal solution. However, time andexperience have demonstrated that this classic top-down
approach, which developed and imposed inappropriate policies
and imported inappropriate technologies was not only a wasteof resources, but also served in many cases to exacerbate thelife support system of the people living in the affected areas.
A report in 1990 by the World Bank stated that “lack ofunderstanding of traditional production systems, which weredeveloped over time through adaptation to difficult conditions”
is a key reason for the lack of success of most development
efforts in the drylands. The literature indicates a consensus
that appropriate policy and technology are vital and must be
developed with the participation of local people, who wouldfind a policy or technology appropriate based on a specificcombination of factors. In this context, socio-economic,
gender, and cultural considerations are key factors” (UNCCD,2005). In accordance with this understanding, people havestarted to pay attention to “traditional knowledge” in thecontext of the Convention to Combat Desertification (CCD).
Traditional knowledge and the empirical knowledge basedon the local people’s observations must be used to combat a
negative heritage of combating desertification. In short,scientists must work with the local people.
4.2. Lessons to be learned: Developing comprehensive
measures to control the alien invasive species
There are many lessons to be learned from the “mistakes”
made by scientists, administrators, and NGO workers.
Though not intended to harm, and it is critical to go beyond
criticism and continue to attempt doing the best as scientists.
Development of comprehensive measures to control thealien invasive species, mesquite, is necessary to combat thenegative heritage of combating desertification in Sudan.
Through mistakes may be inevitable, it is necessary to keep
tackling the issue based on a deeper understanding of the issue

in cooperation with administrators and NGO workers as well
as local people.
Acknowledgement
This study was carried out in cooperation with the research
project “A Study of Human Subsistence Ecosystems in Arab
Societies: To Combat Livelihood Degradation for the Post-oilEra” (Project Leader: Hiroshi Nawata, Research Period:2008-2013), at the Research Institute for Humanity and Nature(RIHN), Kyoto, Japan.

References
Abdel Bari E. (1986): The Identity of the common mesquite,(Prosopis spp.) in the Sudan. Agricultural research
Corporation. Forestry Research Centre Khrtoum-Sudan
Prosopis project. Pamphlet No. 1. pp. 20.
Abdel Garbar A.E.I. (1988): “Prosopis chilensis in Sudan: Non
Conventional Animal Feed Resources” In Habit M.A. eds.
The Current State of Knowledge of Prosopis juliflora, FAO,
pp. 371-377.
Babiker A.G.T. (2006): Mesquite (Prosopis spp.) in Sudan:
history, distribution and control. FAO, Problems posed by
the introduction of Prosopis spp. in selected countries, pp.
11-20.
Broun A.F., Massey R.E. (1929): Flora of the Sudan: Thomas
Murby and CO. pp 376
Bukhari Y. M. (1997): Cytoevolution of taxa in Acacia andProsopis (Mimosaceae). Australian Journal of Botany, 45:879-891.
Burkart A. (1976): A monograph of the genus Prosopis(Leguminosae subfam. Mimosoideae). (Part 1 and 2).
Catalogue of the recognized species of Prosopis. Journal ofthe Arnold Arboretum, 57: 219-249 and 450-525.
Elfadl M.A., (1997): Management of Prosopis juliflora for Usein Agroforestry Systems in the Sudan. Ph.D. Thesis, TropicalUnit, University of Helenski. Tropical Forestry Report, 16:
107pp
El houri A.A. (1986): Some aspects of dryland afforestation inthe Sudan, with special reference to Acacia tortilis (Frosk)
hayne, Acacia seyal willd. and Prosopis chilensis (Molina)
Stunz. Forest Ecology and Management, 16: 209-221.
Fagg C.W., Stewart J.L. (1994): The value of Acacia andProsopis in arid and semiarid environments. Journal of Arid
Environments, 27:3-25.
Habit M.A. eds. (1988): The Current State of Knowledge ofProsopis juliflora, FAO.
Harris P.J.C., Pasiecznik, N.M., Bradbury, M. Ramirez, L.
(1988): Problems and Potential of Prosopis in Drylands. InEtkin, N.L., Harris, D.R., Prendergast, H.D.V., Houghton,P.J. eds., Plants for Food and Medicine: Proceedings of theJoint Conference of the Society for Economic Botany andthe International Society for Ethnopharmacology London,
1-6 July 1996. Kew. The Royal Botanic Gardens, pp.
277-293.
Moll E.J. Gubb A.A. (1989): Southern African Shrublands. In
McKell, C.M. eds., The Biology and Utilization of Shrubs,
San Diego, Academic Press, pp. 145-175.
Mwangi E., Swallow B. (2005): Invasion of Prosopis julifloraand Local Livelihoods: Case study from the Lake Baringo
Area of Kenya. World Agroforestry Centre.
Nawata H. (2001): Coastal Resource Use by Camel
Pastoralists: A Case Study of Gathering and Fishing
Activities among the Beja in Eastern Sudan. Nilo-EthiopianStudies, 7: 23-43.
Nawata H. (2002a): Empirical Knowledge on Palatability ofLivestock for Halophytes and Glycophytes: A Case Studyfrom the Beja on the Sudanese Red Sea Coast. Journal ofArid Land Studies, 12(1): 13-26 (in Japanese).
Nawata H. (2002b): Camel Pastoralism Relying on Coastal
Vegetation: A Case Analysis of Pastures among the Beja on
the Sudanese Red Sea Coast. Journal of African Studies, 60:
105-121 (in Japanese).
Nawata H. (2004): Salined Shallow Wells as the Water Points
for Camels: A Case Analysis of the Water Use for Humanand Livestock on the Sudanese Red Sea Coast. Journal ofArid Land Studies, 13(4): 249-264 (in Japanese).
Nawata H. (2009): Reexamining Technology Transfer andDevelopment Policy with the Application of Traditional
Knowledge. In Japan Association for Arid Land Studies eds.,
Encyclopedia of Arid Lands Studies. Maruzen, Tokyo, p.
225. (in Japanese)
Nawata H. (2010): Exploitation and Conservation of Middle
East Tree Resource in the Oil-era: Study of Human
Subsistence Ecosystems in Arab Societies. Annals of Japan
Association for Middle East Studies, 26(1): 137-150.
Pasiecznik N.M. (2001): The Prosopis juliflora - Prosopis
Pallida Complex: A Monograph. HDRA.
Pasiecznik, N.M., Harris P.J.C., Smith S.J. (2004): Identifying
Tropical Prosopis Species: A Field Guide. HDRA.
SWITCH (2006): Battle with Mesquite. SWITCH (in Arabic).
United Nations Convention to Combat Desertification (2005):Promotion of Traditional Knowledge. A Compilation ofUNCCD Documents and Reports from 1997-2003. Bonn:UNCCD, 156p.
Wunder H.G. (1966): Prosopis juliflora in the arid zone ofSudan. UNDP, Forestry Research and Education Project.
Pamphlet No. 26: pp 23.