− | ''Prosopis ''is a genus belonging to the botanical family of ''Fabaceae'', capable to bind atmospheric nitrogen and hence to contribute to soil fertility improvement. The genus comprises 44 species “of which 40 are native to the Americas”[1]. In Africa there are only two native ''Prosopis'' species: ''P. africana'' and ''P. farcta''.<ref name="Geesing et al. (n. d.)">D. Geesing, M. Al-Khawlani, M. L. Abba (n. d.): Management of introduced ''Prosopis'' species: can economic exploitation control an invasive species?” URL: [http://www.fao.org/docrep/007/y5507e/y5507e11.htm http://www.fao.org/docrep/007/y5507e/y5507e11.htm]< </ref>. Most of ''Prosopis'' species, particularly ''P. juliflora'' and ''P. pallida'' (which are of concern in this regard) are fast-growing, very drought resistant and can stand saline soils easily. Due to their high coppicing ability they out-compete native species. Furthermore, they are equipped with several physical and chemical defence mechanisms (thorns, venom etc.) which make them very difficult to manage and unpalatable for animals. They are deep-rooting up to about 20 m and thus can reach water table[1]. Some ''Prosopis'' species are often mentioned as the strongest invaders: “[…] in particular ''P. juliflora'', ''P.glandulosa'',''P. pallida'',''P. chilensis'', ''P. flexuosa ''and''P. ruscifolia'' invade valuable farm- and rangeland and sometimes grow into impenetrable thickets, causing enormous ecological and economic damage as a result of competition with the native vegetation and with agricultural crops.”[[#_edn1|[1]]] It is also assumed that similar species, in particular ''P. juliflora'' and ''P. pallida'', form hybrids which make the identification even more difficult.<br/> | + | ''Prosopis ''is a genus belonging to the botanical family of ''Fabaceae'', capable to bind atmospheric nitrogen and hence to contribute to soil fertility improvement. The genus comprises 44 species “of which 40 are native to the Americas”[1]. In Africa there are only two native ''Prosopis'' species: ''P. africana'' and ''P. farcta''.<ref name="Geesing et al. (n. d.)">D. Geesing, M. Al-Khawlani, M. L. Abba (n. d.): Management of introduced ''Prosopis'' species: can economic exploitation control an invasive species?” URL: [http://www.fao.org/docrep/007/y5507e/y5507e11.htm http://www.fao.org/docrep/007/y5507e/y5507e11.htm] </ref>. Most of ''Prosopis'' species, particularly ''P. juliflora'' and ''P. pallida'' (which are of concern in this regard) are fast-growing, very drought resistant and can stand saline soils easily. Due to their high coppicing ability they out-compete native species. Furthermore, they are equipped with several physical and chemical defence mechanisms (thorns, venom etc.) which make them very difficult to manage and unpalatable for animals. They are deep-rooting up to about 20 m and thus can reach water table <ref name="Geesing et al. (n. d.)">D. Geesing, M. Al-Khawlani, M. L. Abba (n. d.): Management of introduced ''Prosopis'' species: can economic exploitation control an invasive species?” URL: [http://www.fao.org/docrep/007/y5507e/y5507e11.htm http://www.fao.org/docrep/007/y5507e/y5507e11.htm] </ref>. Some ''Prosopis'' species are often mentioned as the strongest invaders: “[…] in particular ''P. juliflora'', ''P.glandulosa'',''P. pallida'',''P. chilensis'', ''P. flexuosa ''and''P. ruscifolia'' invade valuable farm- and rangeland and sometimes grow into impenetrable thickets, causing enormous ecological and economic damage as a result of competition with the native vegetation and with agricultural crops.” <ref name="Geesing et al. (n. d.)">D. Geesing, M. Al-Khawlani, M. L. Abba (n. d.): Management of introduced ''Prosopis'' species: can economic exploitation control an invasive species?” URL: [http://www.fao.org/docrep/007/y5507e/y5507e11.htm http://www.fao.org/docrep/007/y5507e/y5507e11.htm] </ref> It is also assumed that similar species, in particular ''P. juliflora'' and ''P. pallida'', form hybrids which make the identification even more difficult.<br/> |
− | Encroachment of Invasive Alien Species (IAS) is a globally common phenomenon and often has detrimental effects on rural households in developing countries. Ethiopia in particular is affected by invasion of several species of ''Prosopis spp.''– predominantly ''P. juliflora'' – that have been growing out of control for already more than a decade[[#_edn2|[2]]]. The ecological consequences of this woody species encroachment have been devastating since rangeland areas are degraded and forage grass productivity has declined drastically as a result[[#_edn3|[3]]]. Besides impacts on the social fabric and rural livelihood systems, consequences also entail land degradation, which strongly influences the regional and national economic performance. So far, the economics of land degradation have mainly focused on general aspects such as soil erosion, salinisation or land use changes[[#_edn4|[4]]]. | + | Encroachment of Invasive Alien Species (IAS) is a globally common phenomenon and often has detrimental effects on rural households in developing countries. Ethiopia in particular is affected by invasion of several species of ''Prosopis spp.''– predominantly ''P. juliflora'' – that have been growing out of control for already more than a decade <ref name="HDRA(2005)">HDRA (2005): Controlling the spread of ''Prosopis ''in Ethiopia by its utilization, URL: [http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf] </ref>. The ecological consequences of this woody species encroachment have been devastating since rangeland areas are degraded and forage grass productivity has declined drastically as a result <ref name="Angassa et al.(2008)">Angassa, Ayana, Oba, Gufu (2008): Effects of management and time on mechanisms of bush encroachment in southern Ethiopia. In: African Journal of Ecology, Vol. 46, Iss. 2, pp. 186-196. URL: [http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x] and Coppock, David Layne, ed. ''The Borana Plateau of Southern Ethiopia: Synthesis of pastoral research, development, and change, 1980-91''. Vol. 5.ILRI (aka ILCA and ILRAD), 1994.</div><div id="edn4"> </ref>. Besides impacts on the social fabric and rural livelihood systems, consequences also entail land degradation, which strongly influences the regional and national economic performance. So far, the economics of land degradation have mainly focused on general aspects such as soil erosion, salinisation or land use changes[[#_edn4|[4]]]. |
| The spatial extension of ''Prosopis ''in Ethiopia is difficult to assess since it is expanding rapidly, up to 18% per year[[#_edn5|[5]]]. According to estimates of Ryan (2011), one million hectares (ha) are already covered by ''Prosopis'' in Ethiopia[[#_edn6|[6]]], of which about 700,000 ha are located in the Afar Region. ''Prosopis'' rapidly spreads across both pastoral and agricultural lands leading to severe losses in ecological functions and, thus, to degradation. Other countries[[#_edn7|[7]]] such as South Africa, Niger, Yemen, Namibia and India are also threatened by environmental degradation through ''Prosopis'' as are surrounding areas in Eritrea, Somalia and Kenya. | | The spatial extension of ''Prosopis ''in Ethiopia is difficult to assess since it is expanding rapidly, up to 18% per year[[#_edn5|[5]]]. According to estimates of Ryan (2011), one million hectares (ha) are already covered by ''Prosopis'' in Ethiopia[[#_edn6|[6]]], of which about 700,000 ha are located in the Afar Region. ''Prosopis'' rapidly spreads across both pastoral and agricultural lands leading to severe losses in ecological functions and, thus, to degradation. Other countries[[#_edn7|[7]]] such as South Africa, Niger, Yemen, Namibia and India are also threatened by environmental degradation through ''Prosopis'' as are surrounding areas in Eritrea, Somalia and Kenya. |
| </div><div id="edn2">[[#_ednref2|[2]]]HDRA (2005): Controlling the spread of ''Prosopis ''in Ethiopia by its utilization, URL: [http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf]</div><div id="edn3">[[#_ednref3|[3]]]Wakie, Tewodros; Evangelista, Paul; Laituri, Melinda (2012): “Utilization assessment of Prosopis juliflora in Afar Region, Ethiopia. US Forest Service, USDA Office of International Programs, USAID Pastoral Livelihoods Initiative II Project (PLI II)[3]Angassa, Ayana, Oba, Gufu (2008): Effects of management and time on mechanisms of bush encroachment in southern Ethiopia. In: African Journal of Ecology, Vol. 46, Iss. 2, pp. 186-196. URL: [http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x] and Coppock, David Layne, ed. ''The Borana Plateau of Southern Ethiopia: Synthesis of pastoral research, development, and change, 1980-91''. Vol. 5.ILRI (aka ILCA and ILRAD), 1994.</div><div id="edn4">[[#_ednref4|[4]]] Gerber, Nicolas (2012): The Economics of Land Degradation and the Cost of Action versus Inaction, ZEF/ IFPRI.</div><div id="edn5">[[#_ednref5|[5]]] Peter Felker (2008): personal communication cited in: Fiona Flintan (2008): Prosopis control and/ or utilization, URL: [http://www.disasterriskreduction.net/fileadmin/user_upload/drought/docs/ELMT_Good_Practice_Bibliography_Prosopis http://www.disasterriskreduction.net/fileadmin/user_upload/drought/docs/ELMT_Good_Practice_Bibliography_Prosopis][2].pdf</div><div id="edn6">[[#_ednref6|[6]]] Ryan, F. (2011): US Forest Service Technical Assistance Trip to Ethiopia: Invasive Species Management: US Forest Service, cited in: Yibekal Abebe Tessema: Ecological and Economic Dimensions of the Paradoxical Invasive Species- Prosopis juliflora and Policy Challenges in Ethiopia. In: Journal of Economics and Sustainable Development, Vol.3, No.8, 2012.</div><div id="edn7">[[#_ednref7|[7]]]Pasiecznik, N.M. et al. (2001): The ''Prosopis juliflora''- ''Prosopis pallida ''Complex: A Monograph, HDRA Coventry UK</div><div id="edn8">[[#_ednref8|[8]]] Wakie, Tewodros; Evangelista, Paul; Laituri, Melinda (2012): Utilization Assessment of ''Prosopis juliflora ''in Afar Region, Ethiopia</div><div id="edn9">[[#_ednref9|[9]]] Central Statistical Agency of Ethiopia (2010)</div><div id="edn10">[[#_ednref10|[10]]] Mengistu, Alemayehu (2006): Country Pasture/Forage Resource Profiles. Ethiopia, FAO.</div><div id="edn11">[[#_ednref11|[11]]] [http://ewnhs.org.et/wp-content/uploads/downloads/2011/03/Biodiversity-Hotspots-of-Ethiopia.pdf http://ewnhs.org.et/wp-content/uploads/downloads/2011/03/Biodiversity-Hotspots-of-Ethiopia.pdf]</div><div id="edn12">[[#_ednref12|[12]]]Abiyot Berhanu and Getachew Tesfaye (2006): “THE ''PROSOPIS ''DILEMMA, IMPACTS ON DRYLANDBIODIVERSITY AND SOME CONTROLLING METHODS“,JOURNAL OF THE DRYLANDS 1(2): 158-164, 2006<br/></div><div id="edn13">[[#_ednref13|[13]]] Rettberg, S. and Müller-Mahn, D. (2012): Human-environment interactions: The invasion of Prosopis Juliflora in the dry lands of Northeast Ethiopia. In: Mol, L. and Sternberg, T. (Eds.): Changing deserts, Cambridge: Whitehorse Press: pp. 297-316.<br/></div><div id="edn14">[[#_ednref14|[14]]] HDRA (2005): Controlling the spread of ''Prosopis'' in Ethiopia by its utilization, URL: [http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf]</div><div id="edn15">[[#_ednref15|[15]]] Rettberg, S. and Müller-Mahn, D. (2012): Human-environment interactions: The invasion of Prosopis Juliflora in the dry lands of Northeast Ethiopia. In: Mol, L. and Sternberg, T. (Eds..): Changing deserts, Cambridge: Whitehorse Press: pp. 297-316.</div><div id="edn16">[[#_ednref16|[16]]] Böhnert, Elke (2013): German Ethiopian Financial Cooperation. Territorial approach to adjusting to climate change in Eastern Ethiopia 30932. Measures to increase pastoralists’ drought resilience in the Afar National Regional State (unpublished)</div><div id="edn17">[[#_ednref17|[17]]] Müller-Mahn, D., Rettberg, S., Getachew, G. (2010): Pathways and dead ends of pastoral development among the Afar Karrayu in Ethiopia. In: European Journal for Development Research 22 (5), pp. 660-677.<br/></div></div> | | </div><div id="edn2">[[#_ednref2|[2]]]HDRA (2005): Controlling the spread of ''Prosopis ''in Ethiopia by its utilization, URL: [http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf]</div><div id="edn3">[[#_ednref3|[3]]]Wakie, Tewodros; Evangelista, Paul; Laituri, Melinda (2012): “Utilization assessment of Prosopis juliflora in Afar Region, Ethiopia. US Forest Service, USDA Office of International Programs, USAID Pastoral Livelihoods Initiative II Project (PLI II)[3]Angassa, Ayana, Oba, Gufu (2008): Effects of management and time on mechanisms of bush encroachment in southern Ethiopia. In: African Journal of Ecology, Vol. 46, Iss. 2, pp. 186-196. URL: [http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x http://dx.doi.org/10.1111/j.1365-2028.2007.00832.x] and Coppock, David Layne, ed. ''The Borana Plateau of Southern Ethiopia: Synthesis of pastoral research, development, and change, 1980-91''. Vol. 5.ILRI (aka ILCA and ILRAD), 1994.</div><div id="edn4">[[#_ednref4|[4]]] Gerber, Nicolas (2012): The Economics of Land Degradation and the Cost of Action versus Inaction, ZEF/ IFPRI.</div><div id="edn5">[[#_ednref5|[5]]] Peter Felker (2008): personal communication cited in: Fiona Flintan (2008): Prosopis control and/ or utilization, URL: [http://www.disasterriskreduction.net/fileadmin/user_upload/drought/docs/ELMT_Good_Practice_Bibliography_Prosopis http://www.disasterriskreduction.net/fileadmin/user_upload/drought/docs/ELMT_Good_Practice_Bibliography_Prosopis][2].pdf</div><div id="edn6">[[#_ednref6|[6]]] Ryan, F. (2011): US Forest Service Technical Assistance Trip to Ethiopia: Invasive Species Management: US Forest Service, cited in: Yibekal Abebe Tessema: Ecological and Economic Dimensions of the Paradoxical Invasive Species- Prosopis juliflora and Policy Challenges in Ethiopia. In: Journal of Economics and Sustainable Development, Vol.3, No.8, 2012.</div><div id="edn7">[[#_ednref7|[7]]]Pasiecznik, N.M. et al. (2001): The ''Prosopis juliflora''- ''Prosopis pallida ''Complex: A Monograph, HDRA Coventry UK</div><div id="edn8">[[#_ednref8|[8]]] Wakie, Tewodros; Evangelista, Paul; Laituri, Melinda (2012): Utilization Assessment of ''Prosopis juliflora ''in Afar Region, Ethiopia</div><div id="edn9">[[#_ednref9|[9]]] Central Statistical Agency of Ethiopia (2010)</div><div id="edn10">[[#_ednref10|[10]]] Mengistu, Alemayehu (2006): Country Pasture/Forage Resource Profiles. Ethiopia, FAO.</div><div id="edn11">[[#_ednref11|[11]]] [http://ewnhs.org.et/wp-content/uploads/downloads/2011/03/Biodiversity-Hotspots-of-Ethiopia.pdf http://ewnhs.org.et/wp-content/uploads/downloads/2011/03/Biodiversity-Hotspots-of-Ethiopia.pdf]</div><div id="edn12">[[#_ednref12|[12]]]Abiyot Berhanu and Getachew Tesfaye (2006): “THE ''PROSOPIS ''DILEMMA, IMPACTS ON DRYLANDBIODIVERSITY AND SOME CONTROLLING METHODS“,JOURNAL OF THE DRYLANDS 1(2): 158-164, 2006<br/></div><div id="edn13">[[#_ednref13|[13]]] Rettberg, S. and Müller-Mahn, D. (2012): Human-environment interactions: The invasion of Prosopis Juliflora in the dry lands of Northeast Ethiopia. In: Mol, L. and Sternberg, T. (Eds.): Changing deserts, Cambridge: Whitehorse Press: pp. 297-316.<br/></div><div id="edn14">[[#_ednref14|[14]]] HDRA (2005): Controlling the spread of ''Prosopis'' in Ethiopia by its utilization, URL: [http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf http://www.gardenorganic.org.uk/pdfs/international_programme/EthiopiaProsopisBrief.pdf]</div><div id="edn15">[[#_ednref15|[15]]] Rettberg, S. and Müller-Mahn, D. (2012): Human-environment interactions: The invasion of Prosopis Juliflora in the dry lands of Northeast Ethiopia. In: Mol, L. and Sternberg, T. (Eds..): Changing deserts, Cambridge: Whitehorse Press: pp. 297-316.</div><div id="edn16">[[#_ednref16|[16]]] Böhnert, Elke (2013): German Ethiopian Financial Cooperation. Territorial approach to adjusting to climate change in Eastern Ethiopia 30932. Measures to increase pastoralists’ drought resilience in the Afar National Regional State (unpublished)</div><div id="edn17">[[#_ednref17|[17]]] Müller-Mahn, D., Rettberg, S., Getachew, G. (2010): Pathways and dead ends of pastoral development among the Afar Karrayu in Ethiopia. In: European Journal for Development Research 22 (5), pp. 660-677.<br/></div></div> |