Trees, agroforestry and livelihoods in dryland Africa

Trees, agroforestry and livelihoods in dryland Africa (TALDA) (2005-2008)

Researcher in charge: Prof. Olavi Luukkanen
Principal researcher: Dr. Mohamed Ahmed Elfadl
Funding period: 1.1. 2005 – 31.12. 2008
Site of research: Viikki Tropical Resources Institute VITRI (Dept. of Forest Ecology), University of Helsinki

Collaborating senior researchers: Prof. Ahmed A. Salih (Director, Forestry Research Centre FRC, Khartoum, Sudan); Doc. Leena Kirjavainen (WIDAGRI Consultants); Prof. Teemu Teeri (UHDepartment of Applied Biology); Prof. John Sumelius (UH Department of Economics and Management); Prof. Pertti Hari (UH Dept. of Forest Ecology); Dr Kristina Lindström (UH Department of Applied Chemistry and Microbiology); Dr Abdelazim M. Ibrahim (General Manager, Forests National Corporation FNC, Khartoum, Sudan); Dr Elsiddig Elnour & Dr (Ms) Huda Sharawi (Faculty of Forestry, University of Khartoum, Sudan)


The United Nations Millennium Declaration states reduction of poverty and hunger as a top development priority for the coming decade. The Finnish government has committed itself to this goal and to supporting the least developed countries in particular. Sudan is the largest country in Africa, showing diversity in ecology, land-use and culture. It was also from 1978-1991 one of the leading recipients of Finnish forest-sector development aid. VITRI, under the leadership of Olavi Luukkanen, has since 1983 carried out forest research and researcher training in Sudan and developed expertise in dryland ecology and management that is now utilised both in Finland and internationally.

The present proposal is a direct continuation to our work in Sudan in 1998-2000 and 2002-2004; most of the data is collected from ongoing field studies. The general aim is to analyse the role of trees in production system rehabilitation, so as to provide scientific support to new management guidelines. The emphasis is on soil nutrient and water uptake by crops and natural or planted trees, and on intercropping designs. The intraspecific variation in gum arabic and biomass yields and adaptation to soil types is studied in the key agroforestry tree species Acacia senegal. Environmental-economic analyses focus on the potentially invasive alien prosopis tree, which has an 80-year history and now a highly controversial status as a plantation species in Sudan. Social aspects of dryland trees include the role of women as resource managers and the feasibility of community-based dryland forest management. Use of biotechnology for gene conservation is tested with date palm as the model species. Field research sites represent both the sandy soils and natural Acacia senegalforests of western Sudan and the central Sudan clay plain where A. senegalagroforestry is a new but little-researched activity. Results will be used by the responsible Sudanese forestry agency Forests National Corporation, whose core staff has obtained researcher training at VITRI. In tentatively nine other African countries, channels for disseminating the results will be established in an ongoing feasibility study on gum arabic management for the UN Convention to Combat Desertification (UNCCD) carried out by VITRI with Ministry for Foreign Affairs support. The project offers a framework for international dryland researcher training.

Publications in peer-reviewed scientific journals and books

  • Ballal, M.E., Elsiddig, E.A., Elfadl, M.A. & Luukkanen, O. 2005. Gum arabic yield trends in differently managed Acacia senegal stands in western Sudan. Agroforestry Systems 63: 237-245. Abstract
  • Raddad, E. Y., Salih, A.A., El Fadl, M.A., Kaarakka, V. & Luukkanen, O. 2005. Symbiotic nitrogen fixation in eight Acacia senegalprovenances in dryland clays of the Blue Nile Sudan estimated by the 15N natural abundance method. Plant and Soil 63: 261-269. Abstract
  • Ballal, M.E., Elsiddig, E. A., Elfadl, M.A. & Luukkanen, O. 2005. Relationship between Environmental factors, tapping dates, tapping intemsity and gum arabic yield of an Acacia senegal plantation in western Sudan. Journal of Arid Environment 63: 379-389. Abstract
  • Laxen, J., Elfadl, M.A., Kaarakka, V., & Luukkanen, O. 2005. Research and Development for Sustainable land-Use in Dryland Africa: 25 Years of Finland-Sudan Forestry Cooperation. Pp. 167-188. In: Olli Hietanen (ed.), University Partnerships for International Development: Finnsih Development Knowledge. Finland Futures Research Centre, Turku School of Economics and Business Administration. 315 p.
  • Gaafar, A.M., Salih, A.A., Luukkanen, O., Elfadl, M.A., & Kaarakka, V. 2006. Improving the traditional Acacia senegal-crop system in Sudan: the effect of tree density on water use, gum production and crop yields. Agroforestry Systems 66: 1-11. Abstract
  • Elfadl, M.A. & Luukkanen, O. 2006. Ecological strategies of Prosopis juliflora in the arid environment of the Sudan: 1. Leaf gas exchange approach. Journal of Arid Environment 66: 1-15. doi: 10.1016/j.jaridenv.2005.09.006. Abstract
  • Raddad, E. Y. and Luukkanen, O. 2006. Adaptive genetic variation in water-use efficiency and gum yield in Acacia Senegal provenances grown on clay soil in the Blue Nile region, Sudan. Forest Ecology and Management 226 (2006) 219-229. Abstract
  • Minna Hares, Anu Eskonheimo, Timo Myllyntaus and Olavi Luukkanen, 2006. Environmental literacy in interpreting endangered sustainability: case studies from Thailand and the Sudan. Geoforum 37: 128-144. Abstract
  • Raddad, E.Y, Luukkanen, O., Salih, A.A., Kaarakka, V. and Elfadl, M.A. 2006.
    Productivity and nutrient cycling in young Acacia senega l farming systems on Vertisol in the Blue Nile region, Sudan. Agroforestry Sytems. DOI: 10.1007/s10457-006-9009-6 Abstract

Doctoral theses completed within the project


2. Glover, Edinam K.

3. Eskonheimo, Anu

4. RADDAD, El Amin Yousif Abdalla