Healthy ecosystems benefit humans in various forms,and ecosystem services(ESs)are the benefits reaped by people in various forms.However,increase in global human population and the resulting anthropogenic activities h...Healthy ecosystems benefit humans in various forms,and ecosystem services(ESs)are the benefits reaped by people in various forms.However,increase in global human population and the resulting anthropogenic activities have led to rapid alterations in the composition,structure,and functions of the ecosystems as well as their degradation,increasing the losses associated with ES values.Livelihoods of people in several developing countries are highly dependent on their surrounding ecosystems and the services they provide.Therefore,management and reduction of ecosystem modification are required;especially in developing countries,this requirement is even more urgent.In Africa,ecosystem-based studies are limited and in still in their initial stages.Hence,this paper examines dynamic Ethiopian ESs in Africa from 2010 to 2019 based on a systematic bibliometric analysis of articles from the Scopus database using a set of standard criteria.In total,73 articles were published on Africa,including Ethiopia.The results reveal that the spatial distribution trend of ES studies is unevenly distributed,where most studies were conducted in the central highlands,followed by southwestern regions,with no studies on the western part of Ethiopia.Regarding service providing units(SPUs),the urban ecosystem and agroecosystem accounted for 25%and mixed ecosystems accounted for 20%.Furthermore,a total of 67 specific ESs were investigated by researchers,among which 81.25%of the specific ESs were classified into two ES categories.Provisioning ES(40.29%)dominated across all of the ES types while the cultural ES(5.97%)type has received little attention.Based on keywords,ESs were strongly linked to South Africa,Ethiopia,and biodiversity.In terms of the co-authorship network,authors from the United Kingdom,Italy,Burkina Faso,the Netherlands,and Germany actively collaborated with the Ethiopian researchers,and approximately 50%of the studies were aimed at estimating the value of the ESs through an applied mixed mode of ES study approaches.This review indicates that,due to land use land cover(LULC)changes from 1985 to 2015,approximately US$149.5 million or US$4.98 million annually in ES values were lost.Moreover,there is a critical need to extend ES studies to entire Ethiopia to capture the spatial and socioeconomic uniqueness of various ecosystems and focus more on multiple ES categories as a means to address ES synergies and provide unit-services to strengthen the relations among benefiting areas in Ethiopia.展开更多
Green space(GS)is a central element of urban ecosystems while,urbanization is substantially changed green land into impervious ecosystems,which has then troubled the equilibrium of the surface thermal energy and the e...Green space(GS)is a central element of urban ecosystems while,urbanization is substantially changed green land into impervious ecosystems,which has then troubled the equilibrium of the surface thermal energy and the ecosystem services fluxes.This study was intended to explore the response of relative land surface temperature(RLST)intensities to the urban ecosystem-agglomeration dynamics as well as regional thermal environment(RTE)effects on green space in four major cities(i.e.,Addis Ababa-Hawassa-Adama-Bahir Dar)of Ethiopia from 1990−2020,using a set of remote sensing images,single-channel algorism,and geospatial analyses.The results showed the trends of GS evolution were:GS loss>GS gain>GS exchange.Besides,the distinct ecosystems as high-temperature zones(RLST more than 2°C)were gradually augmented and significantly intensified between 2010−2020 in all cities,while the proportion of green space was significantly decreased.Due to this,the segregated urban heat islands were gradually inter-weaved and interacted with each other and forming regional heat islands.However,the newly established green space has fewer cooling effects than urban forest and greenery,because RLST of green space loss and gain are substantially disparate.We also confirmed that the regional thermal environment is not only prejudiced by ecosystem patterns and processes besides substantially conquered by the particular GS change processes as well as RHI dynamics and evolution rate.展开更多
Background:Sustainable land management interventions were introduced in Geda watershed in 2012 to reduce soil erosion,improve water infiltration,and increase plant-carbon inputs into the soil.This study explored the i...Background:Sustainable land management interventions were introduced in Geda watershed in 2012 to reduce soil erosion,improve water infiltration,and increase plant-carbon inputs into the soil.This study explored the impact of the interventions on biomass production,carbon stock,and carbon sequestration.Stratified sampling was employed in the main and the dry seasons in the treated and untreated sub-watersheds that are found adjacent to each other.Above-and below-ground plant biomass,soil bulk density and organic carbon in 0-15-and 15-30-cm depths,and soil moisture content in 0-20-and 20-40-cm depths were collected from the crop,grazing,and tree lucerne plots.All analyses were performed based on standard procedures.Results:Plant biomass production,carbon stock,and carbon sequestration varied highly significantly(P≤0.001)among sub-watersheds,landscape positions,and land uses.Higher mean values were observed for treated subwatershed,lower landscape position,and tree lucerne plot.The higher mean values in the lower landscape position of the treated sub-watershed were due to tree lucerne plantation.Similarly,topsoil(0-15 cm)carbon stock was statistically higher(P≤0.001)in the treated sub-watershed and at tree lucerne plot(P≤0.05).In addition,carbon stock by sub-surface soil(15-30 cm)was significantly higher(P≤0.001)in the treated sub-watershed under crop and grazing lands but the higher value was in cropland and in the upper position.This could be due to the decomposition of organic materials from biomasses of crops and biological supporting measures(tree lucerne and Phalaris)facilitated by tillage.Six years of sustainable land management interventions led to the sequestration of 12.25,7.77,and 13.5 Mg C ha^(−1) under cropland,tree lucerne,and grazing plots,respectively.Conclusion:Sustainable land management interventions revealed auspicious ecological impacts in Geda watershed in terms of improving plant biomass production,carbon stock,and correspondingly capturing higher carbon dioxide equivalent taking untreated sub-watershed as a baseline.Prohibition of free grazing was the key element of the intervention to reduce biomass export and increase carbon sequestration in the treated sub-watershed.Thus,sustaining tree lucerne plants as a conservation measure and the prohibition of free grazing practices are principally essential.展开更多
Background:Land degradation through soil erosion by water is severe in the highlands of Ethiopia.In order to curb this problem,the government initiated sustainable land management interventions in different parts of t...Background:Land degradation through soil erosion by water is severe in the highlands of Ethiopia.In order to curb this problem,the government initiated sustainable land management interventions in different parts of the country since 2008,and in Geda watershed since 2012.However,the impacts of the interventions on soil properties were not assessed so far.Thus,this study investigated the impacts of sustainable land management interventions on selected soil properties in Geda watershed.Soil samples were collected from treated and untreated subwatersheds at the upper and lower landscape positions,from cropland and grazing lands at two soil depths(0-15 cm and 15-30 cm).Selected soil physicochemical properties were assessed with respect to landscape position,land-use type,and soil depth in both treated and untreated sub-watersheds.Results:Generally,most of the soil physicochemical properties differed greatly across sub-watersheds,land-use types,and soil depths.Clay,electrical conductivity,total N,available P,exchangeable K,and organic carbon were higher in the treated sub-watershed,whereas sand,silt,bulk density,and pH were higher in the untreated subwatershed.The higher sand,silt,and bulk density could be attributed to erosion,while the higher pH could be due to the higher exchangeable Na in the untreated sub-watershed.Most of the selected soil chemical properties were not affected by landscape position,but land-use type affected available P and organic carbon with higher mean values at croplands than at grazing lands,which could be ascribed to the conservation structure and tillage of the soils in that conservation structures trap and accumulate transported organic materials from the upper slope,while tillage facilitates aeration and decomposition processes.Conclusion:Sustainable land management interventions improved soil physicochemical properties and brought a positive restoration of the soil ecosystem.Maintaining the soil conservation measures and enhancing community awareness about the benefits,coupled with management of livestock grazing are required to sustain best practices.展开更多
文摘Healthy ecosystems benefit humans in various forms,and ecosystem services(ESs)are the benefits reaped by people in various forms.However,increase in global human population and the resulting anthropogenic activities have led to rapid alterations in the composition,structure,and functions of the ecosystems as well as their degradation,increasing the losses associated with ES values.Livelihoods of people in several developing countries are highly dependent on their surrounding ecosystems and the services they provide.Therefore,management and reduction of ecosystem modification are required;especially in developing countries,this requirement is even more urgent.In Africa,ecosystem-based studies are limited and in still in their initial stages.Hence,this paper examines dynamic Ethiopian ESs in Africa from 2010 to 2019 based on a systematic bibliometric analysis of articles from the Scopus database using a set of standard criteria.In total,73 articles were published on Africa,including Ethiopia.The results reveal that the spatial distribution trend of ES studies is unevenly distributed,where most studies were conducted in the central highlands,followed by southwestern regions,with no studies on the western part of Ethiopia.Regarding service providing units(SPUs),the urban ecosystem and agroecosystem accounted for 25%and mixed ecosystems accounted for 20%.Furthermore,a total of 67 specific ESs were investigated by researchers,among which 81.25%of the specific ESs were classified into two ES categories.Provisioning ES(40.29%)dominated across all of the ES types while the cultural ES(5.97%)type has received little attention.Based on keywords,ESs were strongly linked to South Africa,Ethiopia,and biodiversity.In terms of the co-authorship network,authors from the United Kingdom,Italy,Burkina Faso,the Netherlands,and Germany actively collaborated with the Ethiopian researchers,and approximately 50%of the studies were aimed at estimating the value of the ESs through an applied mixed mode of ES study approaches.This review indicates that,due to land use land cover(LULC)changes from 1985 to 2015,approximately US$149.5 million or US$4.98 million annually in ES values were lost.Moreover,there is a critical need to extend ES studies to entire Ethiopia to capture the spatial and socioeconomic uniqueness of various ecosystems and focus more on multiple ES categories as a means to address ES synergies and provide unit-services to strengthen the relations among benefiting areas in Ethiopia.
文摘Green space(GS)is a central element of urban ecosystems while,urbanization is substantially changed green land into impervious ecosystems,which has then troubled the equilibrium of the surface thermal energy and the ecosystem services fluxes.This study was intended to explore the response of relative land surface temperature(RLST)intensities to the urban ecosystem-agglomeration dynamics as well as regional thermal environment(RTE)effects on green space in four major cities(i.e.,Addis Ababa-Hawassa-Adama-Bahir Dar)of Ethiopia from 1990−2020,using a set of remote sensing images,single-channel algorism,and geospatial analyses.The results showed the trends of GS evolution were:GS loss>GS gain>GS exchange.Besides,the distinct ecosystems as high-temperature zones(RLST more than 2°C)were gradually augmented and significantly intensified between 2010−2020 in all cities,while the proportion of green space was significantly decreased.Due to this,the segregated urban heat islands were gradually inter-weaved and interacted with each other and forming regional heat islands.However,the newly established green space has fewer cooling effects than urban forest and greenery,because RLST of green space loss and gain are substantially disparate.We also confirmed that the regional thermal environment is not only prejudiced by ecosystem patterns and processes besides substantially conquered by the particular GS change processes as well as RHI dynamics and evolution rate.
基金This research was done by the financial support from the post graduate offices of Addis Ababa University and Debre Berhan University,and Africa RISINGa program financed by the United States Agency for International Development(USAID)as part of the United States Government’s Feed the Future Initiative.
文摘Background:Sustainable land management interventions were introduced in Geda watershed in 2012 to reduce soil erosion,improve water infiltration,and increase plant-carbon inputs into the soil.This study explored the impact of the interventions on biomass production,carbon stock,and carbon sequestration.Stratified sampling was employed in the main and the dry seasons in the treated and untreated sub-watersheds that are found adjacent to each other.Above-and below-ground plant biomass,soil bulk density and organic carbon in 0-15-and 15-30-cm depths,and soil moisture content in 0-20-and 20-40-cm depths were collected from the crop,grazing,and tree lucerne plots.All analyses were performed based on standard procedures.Results:Plant biomass production,carbon stock,and carbon sequestration varied highly significantly(P≤0.001)among sub-watersheds,landscape positions,and land uses.Higher mean values were observed for treated subwatershed,lower landscape position,and tree lucerne plot.The higher mean values in the lower landscape position of the treated sub-watershed were due to tree lucerne plantation.Similarly,topsoil(0-15 cm)carbon stock was statistically higher(P≤0.001)in the treated sub-watershed and at tree lucerne plot(P≤0.05).In addition,carbon stock by sub-surface soil(15-30 cm)was significantly higher(P≤0.001)in the treated sub-watershed under crop and grazing lands but the higher value was in cropland and in the upper position.This could be due to the decomposition of organic materials from biomasses of crops and biological supporting measures(tree lucerne and Phalaris)facilitated by tillage.Six years of sustainable land management interventions led to the sequestration of 12.25,7.77,and 13.5 Mg C ha^(−1) under cropland,tree lucerne,and grazing plots,respectively.Conclusion:Sustainable land management interventions revealed auspicious ecological impacts in Geda watershed in terms of improving plant biomass production,carbon stock,and correspondingly capturing higher carbon dioxide equivalent taking untreated sub-watershed as a baseline.Prohibition of free grazing was the key element of the intervention to reduce biomass export and increase carbon sequestration in the treated sub-watershed.Thus,sustaining tree lucerne plants as a conservation measure and the prohibition of free grazing practices are principally essential.
基金This research was undertaken with support from Africa RISING,a program financed by the United States Agency for International Development(USAID)as part of the United States Government’s Feed the Future Initiative.
文摘Background:Land degradation through soil erosion by water is severe in the highlands of Ethiopia.In order to curb this problem,the government initiated sustainable land management interventions in different parts of the country since 2008,and in Geda watershed since 2012.However,the impacts of the interventions on soil properties were not assessed so far.Thus,this study investigated the impacts of sustainable land management interventions on selected soil properties in Geda watershed.Soil samples were collected from treated and untreated subwatersheds at the upper and lower landscape positions,from cropland and grazing lands at two soil depths(0-15 cm and 15-30 cm).Selected soil physicochemical properties were assessed with respect to landscape position,land-use type,and soil depth in both treated and untreated sub-watersheds.Results:Generally,most of the soil physicochemical properties differed greatly across sub-watersheds,land-use types,and soil depths.Clay,electrical conductivity,total N,available P,exchangeable K,and organic carbon were higher in the treated sub-watershed,whereas sand,silt,bulk density,and pH were higher in the untreated subwatershed.The higher sand,silt,and bulk density could be attributed to erosion,while the higher pH could be due to the higher exchangeable Na in the untreated sub-watershed.Most of the selected soil chemical properties were not affected by landscape position,but land-use type affected available P and organic carbon with higher mean values at croplands than at grazing lands,which could be ascribed to the conservation structure and tillage of the soils in that conservation structures trap and accumulate transported organic materials from the upper slope,while tillage facilitates aeration and decomposition processes.Conclusion:Sustainable land management interventions improved soil physicochemical properties and brought a positive restoration of the soil ecosystem.Maintaining the soil conservation measures and enhancing community awareness about the benefits,coupled with management of livestock grazing are required to sustain best practices.
