埃塞俄比亚西北部半干旱地区居民安置点附近木本植被变化规律（英文）
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摘要
公共牧场为数百万牧民和农牧民提供多样化的生态系统服务。将受贫穷困扰的社区居民重新安置到迄今无人居住的社区牧场和森林,是整个非洲撒哈拉以南地区的一种普遍做法,但这对牧场和林地资源的可持续利用构成了威胁。为了解居民的迁移行为对埃塞俄比亚西北部半干旱林地的影响,采用方差分析和典范对应分析(CCA)方法,对埃塞俄比亚西北部半干旱林地的23个安置村14年的卫星影像和3个旧移民点、3个新移民点、2个难民营和1个保护区的木本植物区系数据进行了分析。各类型居民点的归一化植被指数(NDVI)和冠层盖度均随干扰梯度的减小而减小,但变化幅度则因聚落类型而异。与旧的安置区和保护区相比,难民营和新安置区的树冠覆盖有限。除难民营外,所有地点的木本植被高度等级均呈J形分布,表明植被呈下降趋势。CCA结果表明,居民点类型、海拔高度和干扰梯度等变量对不同居民地的木本植物多样性有显著影响。个别物种对干扰的反应比较表明,低饲料价值的入侵物种,如色穗花(Dichrostachys cinerea),许多金合欢属植物种的比例和盖度都在增加,而以牺牲一些多用途的物种为代价,包括罗望子(Tamarindus indica)、非洲黑檀(Diospyros mespiliformis)和光亮紫檀(Pterocarpus lucens)。在没有植被使用管控的情况下,居民的重新定居安置会导致总体植被盖度下降,植物区系多样性发生变化,将为物种的入侵提供机会。
Communal rangelands provide diverse ecosystem services to millions of pastoralists and agro-pastoralists. Resettling destitute communities into hitherto uninhabited communal rangelands and forests, a common practice throughout Sub-Saharan Africa, is a threat to the sustainable use of range and forest land resources. In order to understand the effect of resettlement on a semi-arid woodland in northwestern Ethiopia, satellite imagery of 23 resettlement villages taken over a period of fourteen years, and woody vegetation floristic data for three old resettlements, three new resettlements, two refugee camps and one protected area were analyzed using ANOVA and canonical correspondence analysis(CCA). The normalized differential vegetation index(NDVI) and canopy cover around all village types decreased with disturbance gradients, while the magnitude of change varied according to the type of settlement. Limited canopy cover was observed in refugee camps and new resettlements, compared to old resettlements and protected areas. Woody vegetation height class showed a J shaped distribution in all sites except refugee camps(RC), indicating a decline in vegetation. CCA showed that variables like site type, altitude and disturbance gradient significantly affected the diversity of woody species at the different sites. Comparison of individual species responses to disturbances indicated that low fodder value invaders like Dichrostachys cinerea, and many Acacia species were increasing in proportion and coverage at the expense of some multipurpose species including Tamarindus indica, Diospyros mespiliformis, and Pterocarpus lucens. In the absence of regulated vegetation use, resettlements result in a decline in overall vegetation cover and a shift in floristic diversity in favor of invasive species.
Communal rangelands provide diverse ecosystem services to millions of pastoralists and agro-pastoralists. Resettling destitute communities into hitherto uninhabited communal rangelands and forests, a common practice throughout Sub-Saharan Africa, is a threat to the sustainable use of range and forest land resources. In order to understand the effect of resettlement on a semi-arid woodland in northwestern Ethiopia, satellite imagery of 23 resettlement villages taken over a period of fourteen years, and woody vegetation floristic data for three old resettlements, three new resettlements, two refugee camps and one protected area were analyzed using ANOVA and canonical correspondence analysis(CCA). The normalized differential vegetation index(NDVI) and canopy cover around all village types decreased with disturbance gradients, while the magnitude of change varied according to the type of settlement. Limited canopy cover was observed in refugee camps and new resettlements, compared to old resettlements and protected areas. Woody vegetation height class showed a J shaped distribution in all sites except refugee camps(RC), indicating a decline in vegetation. CCA showed that variables like site type, altitude and disturbance gradient significantly affected the diversity of woody species at the different sites. Comparison of individual species responses to disturbances indicated that low fodder value invaders like Dichrostachys cinerea, and many Acacia species were increasing in proportion and coverage at the expense of some multipurpose species including Tamarindus indica, Diospyros mespiliformis, and Pterocarpus lucens. In the absence of regulated vegetation use, resettlements result in a decline in overall vegetation cover and a shift in floristic diversity in favor of invasive species.
引文
Abebaw D,Kassa H,Kassie G T,et al.2012.Dry forest based livelihoods in resettlement areas of Northwestern Ethiopia.Forest Policy and Economics,20:72-77.
Aerts R.,Nyssen J,Haile M.2009.On the difference between“exclosures”and“enclosures”in ecology and the environment.Journal of Arid Environments,73:762-763.
Ali M.2010.Post-resettlement status of soil degradation and land management practices at the Gubalafto Wereda,north Wollo,Ethiopia:The case of three selected Kebeles.MSc,Addis Ababa univesity.
Asaah E K.,Tchoundjeu Z,Leakey RR,et al.2011.Trees,agroforestry and multifunctional agriculture in Cameroon.International Journal of Agricultural Sustainability,9:110-119.
Asefa D,Oba G,Weladji R et al..2003.An assessment of restoration of biodiversity in degraded high mountain grazing lands in northern Ethiopia.Land degradation&development,14:25-38.
Augustine D J,Mcnaughton S J.2004.Regulation of shrub dynamics by native browsing ungulates on East African rangeland.Journal of Applied Ecology,41:45-58.
Mulubrhan B,Eik LO,Yayneshet T.2015.There is more in fodder trees than their nutritional values:local valuation of indigenous fodder trees and shrubs by pastoral and agrarian communities in northern Ethiopia.Forests,Trees and Livelihoods,24(2):112-127.
Bates D.2002.Environmental Refugees?Classifying Human Migrations Caused by Environmental Change.Population and Environment,23:465-477.
Berry L.2008.The impact of environmental degradation on refugee-host relations:a case study from tanzania,UNHCR,Policy Development and Evaluation Service.
Borah N,Athokpam F D,Garkoti S.2014.Structural and compositional variations in undisturbed and disturbed tropical forests of Bhuban hills in south Assam,India.International Journal of Biodiversity Science,Ecosystem Services&Management,1-11.
Bottazzi P,Reyes-García V,Crespo D,et al.2013.Productive Diversification and Sustainable Use of Complex Social-Ecological Systems:AComparative Study of Indigenous and Settler Communities in the Bolivian Amazon.Agroecology and Sustainable Food Systems,38:137-164.
Brandt M,Romankiewicz C,Spiekermann R.et al.2014.Environmental change in time series-An interdisciplinary study in the Sahel of Mali and Senegal.Journal of Arid Environments,105:52-63.
Cernea M M,Guggenheim S E.1993.Anthropological approaches to resettlement:policy,practice,and theory,Westview Press.
Dieci P,Viezzoli C.1992.Resettlement and Rural Development in Ethiopia:Social and Economic Research,Training,and Technical Assistance in the Beles Valley,F.Angeli.
Dutoit JT.1990.Feeding-height stratification among African browsing ruminants.African Journal of Ecology,28(1):55-61.
Ezra M,Leslie J,Liang Z.et al.2001.Ecological degradation rural poverty and migration in Ethiopia:a contextual analysis.USA Today,27:1.
Faye M D,Weber J C,Abasse T A,et al.2011.Farmers'preference for tree functions and species in the west African Sahel.Forests,Trees and Livelihoods,20:113-136.
Fisher J,Witkowski E,Erasmus B,et al.2012.Human-modified landscapes:patterns of fine-scale woody vegetation structure in communal savannah rangelands.Environmental Conservation,39:72-82.
Fosse T E.2006.Migration and livelihoods:the Voluntary Resettlement Program in Ethiopia.
Friis I,Demissew S,Breugel P V.2010.Atlas of the potential vegetation of Ethiopia,Det Kongelige Danske Videnskabernes Selskab.
Fuller D,Prince S,Astle W.1997.The influence of canopy strata on remotely sensed observations of savanna-woodlands.International Journal of Remote Sensing,18:2985-3009.
Gebre Y.2003.Resettlement and the unnoticed losers:Impoverishment disasters among the Gumz in Ethiopia.Human organization,62:50-61.
Gebre H,Kindie T,Girma M,and Belay K.(2013).Trend and variability of rainfall in Tigray,northern Ethiopia:analysis of meteorological data and farmers’perception.Academia Journal of Agricultural Research,1(6):088-100.
Hammond L.2008.Strategies of Invisibilization:How Ethiopia's resettlement programme hides the poorest of the poor.Journal of Refugee Studies,21:517-536.
Helman D,Mussery A,Lensky I M and Leu S.2014.Detecting changes in biomass productivity in a different land management regimes in drylands using satellite-derived vegetation index.Soil Use and Management,30:32-39.
Hobbs R J,Arico S,Aronson J,et al.2006.Novel ecosystems:theoretical and management aspects of the new ecological world order.Global ecology and biogeography,15:1-7.
Jackson S and Sleigh A.2000.Resettlement for China's Three Gorges Dam:socio-economic impact and institutional tensions.Communist and Post-Communist Studies,33:223-241.
Kalema V N,Witkowski E T F,Erasmus B F N,et al 2014.The impacts of changes in land use on woodlands in an equatorial african savanna.Land degradation&development,n/a-n/a.
Kariuki J,Machua J,Luvada A,et al.2007.Baseline survey of woodland utilization and degradation around Kakuma Refugee Camp.KEFRI/JOFCA Report,60.
Kassa D G,Ege S,Aspen H,et al.2009.Resettling the discourse on‘resettlement schemes’:towards a new approach.Proceedings of the 16th international conference of Ethiopian studies.Trondheim Norway,867-880.
Keno A.2006.Resettlement dynamics in ethiopia:with special reference to qeto resettlement area,west wellega zone,oromia region.
Kent M.2011.Vegetation description and data analysis:a practical approach,John Wiley&Sons.
Kindt R.and Coe R.2009.Biodiversity R:GUI for biodiversity and community ecology analysis.
Kloos H.and Aynalem A.1989.Settler migration during the 1984/85 resettlement programme in Ethiopia.Geo Journal,19:113-127.
Lemenih M.,Wiersum K,Woldeamanuel T,et al.2011.Diversity and dynamics of management of gum and resin resources in ethiopia:a trade-off between domestication and degradation.Land degradation&development.
Lykke A.1998.Assessment of species composition change in savanna vegetation by means of woody plants'size class distributions and local information.Biodiversity&Conservation,7:1261-1275.
Mekuria W,Veldkamp E,Haile M,et al..2007.Effectiveness of exclosures to restore degraded soils as a result of overgrazing in Tigray,Ethiopia.Journal of Arid Environments,69:270-284.
Mubarak A,Abdalla M.and Nortcliff S.2012.Millet Pennisetum typhoides yield and selected soil attributes as influenced by some tree types of the semi-arid tropics of Sudan.Journal of Arid Environments,77:96-102.
Mulaw G T.2010.Assessing the Rural Resettlement Programme in Ethiopia in Meeting the Livelihood of the People:A Case Study of Metema Yohanes Resettlement Scheme,in the Amhara National Regional State,Erasmus University.
Mulugeta M.and Woldesemait B.2011.The impact of resettlment schemes on land-use/land-cover changes in Ethiopia:A case study from Nonno resettlement sites,Central Ethiopia..
Myers N.2002.Environmental refugees:a growing phenomenon of the21st century.Philosophical Transactions of the Royal Society of London.Series B:Biological Sciences,357:609-613.
Neke K S,Owen-Smith N,and Witkowski E T F.2006.Comparative resprouting response of Savanna woody plant species following harvesting:the value of persistence.Forest Ecology and Management,232:114-123.
Ofcansky T P,and Berry L B.2004.Ethiopia a country study,Kessinger Publishing.
Pankhurst A.2009.Revising Resettlement under Two Regimes in Ethiopia:The 2000s Programme Reviewed in the Light of the 1980s Experience In:Pankhurst,A.&piguet,F.(eds.)Moving people in Ethiopia:development,displacement&the state.James Currey Ltd.
Qgis D.2011.Quantum GIS geographic information system.Open Source Geospatial Foundation Project.
Rahmato D.2003.Resettlement in Ethiopia:the tragedy of population relocation in the 1980s.Forum for Social Studies.
Raymond H.2007.The ecologically noble savage debate.Annu.Rev.Anthropol.,36:177-190.
Shackleton C,Griffin N,Banks,D,et al.1994.Community structure and species composition along a disturbance gradient in a communally managed South African savanna.Vegetatio,115:157-167.
Smith E A,and Wishnie M.2000.Conservation and subsistence in small-scale societies.Annual Review of Anthropology,29(2):493-524.
Tafesse T T.2007.The Migration,Environment and Conflict Nexus in Ethiopia:A Case Study of Amhara Migrant-settlers in East Wollega Zone,Addis Adaba,Eehiopia.
Tang Z,Fang J,Sun J,et al.2011.Effectiveness of protected areas in maintaining plant production.Plos One,6,e19116.
Tefera M M.2009.Challenges and opportunities of voluntary resetlement schemes in Ethiopia:A case from Jirum Gamachu resttlement village,nonno district,Central Ethiopia.Journal of Sustainable Development in Africa,11:83-102.
Tsegaye D,Balehgn M,Gebrehiwot K,et al.2007.The Role of Garsa(Dobera glabra)for household food security at times of food shortage in Abaala Wereda,North Afar:ecological adaptation and socio-economic value:a study from Ethiopia.DCG report.
Wakeling J L,and Bond W J.2007.Disturbance and the frequency of root suckering in an invasive savanna shrub,Dichrostachys cinerea.African Journal of Range&Forage Science,24:73-76.
Wassie A,Sterck F J,and Bongers F.2010.Species and structural diversity of church forests in a fragmented Ethiopian Highland landscape.Journal of Vegetation Science,21:938-948.
Werner C,Zumkier U,Beyschlag et al.2010.High competitiveness of a resource demanding invasive acacia under low resource supply.Plant Ecology,206:83-96.
Wessels K J,Mathieu R,Erasmus B F N,et al.2011.Impact of communal land use and conservation on woody vegetation structure in the Lowveld savannas of South Africa.Forest Ecology and Management,261:19-29.
Whittaker H.2012.Forced Villagization during the Shifta Conflict in Kenya,ca.1963-1968.The International journal of African historical studies,45:343-364.
Woldeamanuel T.2012.Gum and resin-producing species in the drylands of Ethiopia:productive bricolage footprints on the landscape.In:Arts,B.,Bommel,S.,Ros-tonen,M.&Verschoor,G.(eds.)Forest-people interfaces.Wageningen Academic Publishers.
Woldemeskel G.1989.The consequences of resettlement in Ethiopia.African Affairs,88:359-374.
Woube M.2005.Effects of Resettlement Schemes on the Biophysical and Human Environments:The Case of the Gambela Region,Ethiopia,Universal Publishers.
Yayneshet T,Eik L,and Moe S.2009.The effects of exclosures in restoring degraded semi-arid vegetation in communal grazing lands in northern Ethiopia.Journal of Arid Environments,73:542-549.
Yonas B,Beyene F,Negatu L,et al.,2013.Influence of resettlment on pastoral land use and local livelihoods in Southwest Ethiopia.Tropical and Subtropical Agroecosystems,16(1):103-117.
Aerts R.,Nyssen J,Haile M.2009.On the difference between“exclosures”and“enclosures”in ecology and the environment.Journal of Arid Environments,73:762-763.
Ali M.2010.Post-resettlement status of soil degradation and land management practices at the Gubalafto Wereda,north Wollo,Ethiopia:The case of three selected Kebeles.MSc,Addis Ababa univesity.
Asaah E K.,Tchoundjeu Z,Leakey RR,et al.2011.Trees,agroforestry and multifunctional agriculture in Cameroon.International Journal of Agricultural Sustainability,9:110-119.
Asefa D,Oba G,Weladji R et al..2003.An assessment of restoration of biodiversity in degraded high mountain grazing lands in northern Ethiopia.Land degradation&development,14:25-38.
Augustine D J,Mcnaughton S J.2004.Regulation of shrub dynamics by native browsing ungulates on East African rangeland.Journal of Applied Ecology,41:45-58.
Mulubrhan B,Eik LO,Yayneshet T.2015.There is more in fodder trees than their nutritional values:local valuation of indigenous fodder trees and shrubs by pastoral and agrarian communities in northern Ethiopia.Forests,Trees and Livelihoods,24(2):112-127.
Bates D.2002.Environmental Refugees?Classifying Human Migrations Caused by Environmental Change.Population and Environment,23:465-477.
Berry L.2008.The impact of environmental degradation on refugee-host relations:a case study from tanzania,UNHCR,Policy Development and Evaluation Service.
Borah N,Athokpam F D,Garkoti S.2014.Structural and compositional variations in undisturbed and disturbed tropical forests of Bhuban hills in south Assam,India.International Journal of Biodiversity Science,Ecosystem Services&Management,1-11.
Bottazzi P,Reyes-García V,Crespo D,et al.2013.Productive Diversification and Sustainable Use of Complex Social-Ecological Systems:AComparative Study of Indigenous and Settler Communities in the Bolivian Amazon.Agroecology and Sustainable Food Systems,38:137-164.
Brandt M,Romankiewicz C,Spiekermann R.et al.2014.Environmental change in time series-An interdisciplinary study in the Sahel of Mali and Senegal.Journal of Arid Environments,105:52-63.
Cernea M M,Guggenheim S E.1993.Anthropological approaches to resettlement:policy,practice,and theory,Westview Press.
Dieci P,Viezzoli C.1992.Resettlement and Rural Development in Ethiopia:Social and Economic Research,Training,and Technical Assistance in the Beles Valley,F.Angeli.
Dutoit JT.1990.Feeding-height stratification among African browsing ruminants.African Journal of Ecology,28(1):55-61.
Ezra M,Leslie J,Liang Z.et al.2001.Ecological degradation rural poverty and migration in Ethiopia:a contextual analysis.USA Today,27:1.
Faye M D,Weber J C,Abasse T A,et al.2011.Farmers'preference for tree functions and species in the west African Sahel.Forests,Trees and Livelihoods,20:113-136.
Fisher J,Witkowski E,Erasmus B,et al.2012.Human-modified landscapes:patterns of fine-scale woody vegetation structure in communal savannah rangelands.Environmental Conservation,39:72-82.
Fosse T E.2006.Migration and livelihoods:the Voluntary Resettlement Program in Ethiopia.
Friis I,Demissew S,Breugel P V.2010.Atlas of the potential vegetation of Ethiopia,Det Kongelige Danske Videnskabernes Selskab.
Fuller D,Prince S,Astle W.1997.The influence of canopy strata on remotely sensed observations of savanna-woodlands.International Journal of Remote Sensing,18:2985-3009.
Gebre Y.2003.Resettlement and the unnoticed losers:Impoverishment disasters among the Gumz in Ethiopia.Human organization,62:50-61.
Gebre H,Kindie T,Girma M,and Belay K.(2013).Trend and variability of rainfall in Tigray,northern Ethiopia:analysis of meteorological data and farmers’perception.Academia Journal of Agricultural Research,1(6):088-100.
Hammond L.2008.Strategies of Invisibilization:How Ethiopia's resettlement programme hides the poorest of the poor.Journal of Refugee Studies,21:517-536.
Helman D,Mussery A,Lensky I M and Leu S.2014.Detecting changes in biomass productivity in a different land management regimes in drylands using satellite-derived vegetation index.Soil Use and Management,30:32-39.
Hobbs R J,Arico S,Aronson J,et al.2006.Novel ecosystems:theoretical and management aspects of the new ecological world order.Global ecology and biogeography,15:1-7.
Jackson S and Sleigh A.2000.Resettlement for China's Three Gorges Dam:socio-economic impact and institutional tensions.Communist and Post-Communist Studies,33:223-241.
Kalema V N,Witkowski E T F,Erasmus B F N,et al 2014.The impacts of changes in land use on woodlands in an equatorial african savanna.Land degradation&development,n/a-n/a.
Kariuki J,Machua J,Luvada A,et al.2007.Baseline survey of woodland utilization and degradation around Kakuma Refugee Camp.KEFRI/JOFCA Report,60.
Kassa D G,Ege S,Aspen H,et al.2009.Resettling the discourse on‘resettlement schemes’:towards a new approach.Proceedings of the 16th international conference of Ethiopian studies.Trondheim Norway,867-880.
Keno A.2006.Resettlement dynamics in ethiopia:with special reference to qeto resettlement area,west wellega zone,oromia region.
Kent M.2011.Vegetation description and data analysis:a practical approach,John Wiley&Sons.
Kindt R.and Coe R.2009.Biodiversity R:GUI for biodiversity and community ecology analysis.
Kloos H.and Aynalem A.1989.Settler migration during the 1984/85 resettlement programme in Ethiopia.Geo Journal,19:113-127.
Lemenih M.,Wiersum K,Woldeamanuel T,et al.2011.Diversity and dynamics of management of gum and resin resources in ethiopia:a trade-off between domestication and degradation.Land degradation&development.
Lykke A.1998.Assessment of species composition change in savanna vegetation by means of woody plants'size class distributions and local information.Biodiversity&Conservation,7:1261-1275.
Mekuria W,Veldkamp E,Haile M,et al..2007.Effectiveness of exclosures to restore degraded soils as a result of overgrazing in Tigray,Ethiopia.Journal of Arid Environments,69:270-284.
Mubarak A,Abdalla M.and Nortcliff S.2012.Millet Pennisetum typhoides yield and selected soil attributes as influenced by some tree types of the semi-arid tropics of Sudan.Journal of Arid Environments,77:96-102.
Mulaw G T.2010.Assessing the Rural Resettlement Programme in Ethiopia in Meeting the Livelihood of the People:A Case Study of Metema Yohanes Resettlement Scheme,in the Amhara National Regional State,Erasmus University.
Mulugeta M.and Woldesemait B.2011.The impact of resettlment schemes on land-use/land-cover changes in Ethiopia:A case study from Nonno resettlement sites,Central Ethiopia..
Myers N.2002.Environmental refugees:a growing phenomenon of the21st century.Philosophical Transactions of the Royal Society of London.Series B:Biological Sciences,357:609-613.
Neke K S,Owen-Smith N,and Witkowski E T F.2006.Comparative resprouting response of Savanna woody plant species following harvesting:the value of persistence.Forest Ecology and Management,232:114-123.
Ofcansky T P,and Berry L B.2004.Ethiopia a country study,Kessinger Publishing.
Pankhurst A.2009.Revising Resettlement under Two Regimes in Ethiopia:The 2000s Programme Reviewed in the Light of the 1980s Experience In:Pankhurst,A.&piguet,F.(eds.)Moving people in Ethiopia:development,displacement&the state.James Currey Ltd.
Qgis D.2011.Quantum GIS geographic information system.Open Source Geospatial Foundation Project.
Rahmato D.2003.Resettlement in Ethiopia:the tragedy of population relocation in the 1980s.Forum for Social Studies.
Raymond H.2007.The ecologically noble savage debate.Annu.Rev.Anthropol.,36:177-190.
Shackleton C,Griffin N,Banks,D,et al.1994.Community structure and species composition along a disturbance gradient in a communally managed South African savanna.Vegetatio,115:157-167.
Smith E A,and Wishnie M.2000.Conservation and subsistence in small-scale societies.Annual Review of Anthropology,29(2):493-524.
Tafesse T T.2007.The Migration,Environment and Conflict Nexus in Ethiopia:A Case Study of Amhara Migrant-settlers in East Wollega Zone,Addis Adaba,Eehiopia.
Tang Z,Fang J,Sun J,et al.2011.Effectiveness of protected areas in maintaining plant production.Plos One,6,e19116.
Tefera M M.2009.Challenges and opportunities of voluntary resetlement schemes in Ethiopia:A case from Jirum Gamachu resttlement village,nonno district,Central Ethiopia.Journal of Sustainable Development in Africa,11:83-102.
Tsegaye D,Balehgn M,Gebrehiwot K,et al.2007.The Role of Garsa(Dobera glabra)for household food security at times of food shortage in Abaala Wereda,North Afar:ecological adaptation and socio-economic value:a study from Ethiopia.DCG report.
Wakeling J L,and Bond W J.2007.Disturbance and the frequency of root suckering in an invasive savanna shrub,Dichrostachys cinerea.African Journal of Range&Forage Science,24:73-76.
Wassie A,Sterck F J,and Bongers F.2010.Species and structural diversity of church forests in a fragmented Ethiopian Highland landscape.Journal of Vegetation Science,21:938-948.
Werner C,Zumkier U,Beyschlag et al.2010.High competitiveness of a resource demanding invasive acacia under low resource supply.Plant Ecology,206:83-96.
Wessels K J,Mathieu R,Erasmus B F N,et al.2011.Impact of communal land use and conservation on woody vegetation structure in the Lowveld savannas of South Africa.Forest Ecology and Management,261:19-29.
Whittaker H.2012.Forced Villagization during the Shifta Conflict in Kenya,ca.1963-1968.The International journal of African historical studies,45:343-364.
Woldeamanuel T.2012.Gum and resin-producing species in the drylands of Ethiopia:productive bricolage footprints on the landscape.In:Arts,B.,Bommel,S.,Ros-tonen,M.&Verschoor,G.(eds.)Forest-people interfaces.Wageningen Academic Publishers.
Woldemeskel G.1989.The consequences of resettlement in Ethiopia.African Affairs,88:359-374.
Woube M.2005.Effects of Resettlement Schemes on the Biophysical and Human Environments:The Case of the Gambela Region,Ethiopia,Universal Publishers.
Yayneshet T,Eik L,and Moe S.2009.The effects of exclosures in restoring degraded semi-arid vegetation in communal grazing lands in northern Ethiopia.Journal of Arid Environments,73:542-549.
Yonas B,Beyene F,Negatu L,et al.,2013.Influence of resettlment on pastoral land use and local livelihoods in Southwest Ethiopia.Tropical and Subtropical Agroecosystems,16(1):103-117.