Groundnut (Arachis hypogaea L.) is an important cash crop for smallholder farmers in western Ethiopia. However, the yield of the crop is very low mainly because of strong soil acidity and poor soil fertility managemen...Groundnut (Arachis hypogaea L.) is an important cash crop for smallholder farmers in western Ethiopia. However, the yield of the crop is very low mainly because of strong soil acidity and poor soil fertility management. A study conducted to evaluate the effect of lime and mineral phosphorus fertilizer on yield components and yield of groundnut. The treatments consisted of three phosphorus rates (0, 46 and 92 kg P<sub>2</sub>O<sub>5·</sub>ha<sup>-1</sup>), three lime rates (0, 6, and 11 ton lime·ha<sup>-1</sup>), and three groundnut varieties (local cultivar, Werer-961, and Werer-963) was laid-out as a randomized complete design in a factorial arrangement with three replications. The corresponding rates of phosphorus applied per pot of soil (7 kg) amounted to 0, 107 and 215 mg kg·soil<sup>-1</sup> and those of lime amounted to 0, 14, and 26 g kg·soil<sup>-1</sup>. The analysis of variance showed that phenological characters, yield, and yield components significantly affected by interaction of variety, phosphorus, and lime. The highest dry pod yield produced by Werer-963 (2 kg dry pod yield·pot<sup>-1</sup>) in response to the application 11 t·ha<sup>-1</sup> lime and 46 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup>. However, Werer-961 produced medium (1.5 kg dry pod yield·pot<sup>-1</sup>) at 11 t·ha<sup>-1</sup> lime and 92 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup> and the local cultivar produced minimum (1 kg dry pod yield·pot<sup>-1</sup>) at the application of 11 t·ha<sup>-1</sup> lime and 92 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup>. In terms of phosphorus yield efficiency index, Werer-963 was highly efficient (index of 1.71), and Werer-961 was moderately efficient (index of 0.6). However, the local cultivar was inefficient (index of 0.04). It is at, in acidic soil of the study area Werer-963 is the best to be cultivated with application of lime 11 t·ha<sup>-1</sup> and 46 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup> fertilizer, followed by Werer-961. The results of this pot experiment have revealed that farmers in the study area need to switch to cultivating the improved varieties of groundnut rather than local variety with the application of high rates of lime and moderate amounts of phosphorus.展开更多
The present study broadly focused on medicinal plant species collected from wild by the villagers for different purposes in the upper catchment of Dhauli Ganga in Nanda Devi Biosphere Reserve(NDBR),in the central Hima...The present study broadly focused on medicinal plant species collected from wild by the villagers for different purposes in the upper catchment of Dhauli Ganga in Nanda Devi Biosphere Reserve(NDBR),in the central Himalaya.A schedule based survey was conducted during the years 2003-2005 in 15 villages of Chamoli district part of the NDBR.Information was collected from collectors, vaidya(medicine man)and those dealing with domestication and marketing of the medicinal plants. The aim of the study was to understand the prioritiesed medicinal plants,their mode of collection and document their ethnobotanical uses by the Bhotiya tribal communities,in this world heritage site. During the survey,50 medicinal plants belonging to 31 families and 44 genera were documented.Out of these,70% were harvested from the wild,22% were cultivated and 8% were cultivated as well as wild harvested.Of the cultivated species,8% were found growing in the kitchen gardens and 14%in the agricultural fields.However,42%of the plants had their roots and rhizomes used followed by leaves (26%),seeds(10%),seed and leaf(8%),bark and whole plant(6%)and flower(1%).Most plants were reported to be used for rheumatism(16),followed by stomach disorder(14),cold and cough(11),and jaundice(9).Thirty three plants species were reported to have more than one therapeutic uses,while 17 species were reported to be used against single ailment.The distance of villages from road head was one of the factors contributing to the decline in the medicinal plant population in their natural habitats. The availability of medicinal plants increased with increase in distance from road head and also the peoples'dependence on them.Documentation of the traditional knowledge will help in conservation of knowledge and also opportunity for using it for future training and use.The result of this study will help in promoting sustainable cultivation and implementation in conservation protocol of those species,which are in the verge of extinction in this region.展开更多
A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and...A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and three land use types. Analytical results of the collected surface layer soil samples showed significant (P ≤ 0.05) correlation of soil bulk density, OM and total N with elevation. In the lower elevation site (Indaslasie), soil OM content declined by about 43 and 52% compared with that of the two higher elevation sites (Cheguarcudo and Indamariam), respectively. Soil pH, exchangeable acidity, exchangeable Al, OM, total N and available phosphorus also exhibited significant (P ≤ 0.05) disparity across the three land use types of the area. Soils of the forest land were less acidic by 0.43 and 0.68 pH units than the cultivated and grazing lands, respectively. The soil OM content of the cultivated land was significantly lower by about 25 and 35% than the grazing and forest land soils, respectively. Available soil P status was low and showed significant correlations with pH (r = 0.65), exchangeable acidity (r = –0.58) and Al (r = –0.53). In general, the study results revealed altitude did not impose any significant effect in aggravating soil acidity whereas land use type affected significantly not only soil acidity but also the important soil fertility related parameters such as OM, total N and available P contents. Therefore, it can be suggested that besides to the usual acid soil management and/or reclamation practices, introducing proper land use management systems are of paramount importance.展开更多
Plants in the alpine zone mainly depend on the reserved food materials stored in their rhizomes for the next growing season. We investigated the effect of mixed cropping （Phaseolus vulgaris L. var. Pinto） with four ...Plants in the alpine zone mainly depend on the reserved food materials stored in their rhizomes for the next growing season. We investigated the effect of mixed cropping （Phaseolus vulgaris L. var. Pinto） with four rhizomatous medicinal plants, i.e., Angelica glauca, Arnebia benthamii, Rheum emodi and Pleurospermum angelicoides as well as three levels of water stress treatment under two conditions （shade net and open field） on macronutrients （NPK） and biochemicals （carbohydrates and protein）. The experiment was conducted by completely randomized design （CDR）. The data were analyzed with ANOVA as well as CDR. The experimental results show that in all the species shade conditions with sever water stress （SSWS） increased the level of macronutrients （NPK）. However, （N） concentration was highest under shade with mixed cropping （SMIX）. Under SMIX, carbohydrate content was highest than open field control conditions （CONT）. This investigation results demon- strate that mixed cropping of medicinal plants with Phaseolus vulgaris could be a good livelihood option in the mountainous regions of Indian Central Himalaya. And the water-stress conditions along with mixed cropping could improve the biochemical constituents in the rhizome of these species.展开更多
Compiled information on parkland agroforestry tree species in relation to diversity, tree management options and the challenges of the system is important for production and productivity, and biodiversity conservation...Compiled information on parkland agroforestry tree species in relation to diversity, tree management options and the challenges of the system is important for production and productivity, and biodiversity conservation through availing the required information which in turn has an implication to the sustainability of the system and climate change mitigation. So, the aim of this review paper is to compile information on parkland agroforestry practices of Ethiopia, particularly: on tree species diversity, their roles, management options available and challenges of the practice. Parkland agroforestry which is a system practiced by many local populations comprises the large part of agricultural landscapes in Ethiopia and is very important in different aspects such as;for food security, microclimate amelioration, economic benefits, environmental protection, household energy, household utensils, cultural values, traditional medicines, and fodder. There are many indigenous multipurpose tree species scattered on farmlands in Ethiopia, and the common one includes: Millettia ferruginea, Cordia africana, Ficus vasta, Ficus sur, Croton macrostachyus and Faidherbia albida. However, nowadays these trees are facing challenges like: expansion of exotic trees in the expense of the native ones, expansion of cash crops through removal of the parkland trees from the farm area, climate change, land shortage and tenure system which require high emphasis for the production and productivity as well as sustainability of the system especially, in this era of climate change;hence this system is one of climate change mitigation options.展开更多
Improving and understanding of land use and land cover change (LULC) can help in projecting future land use dynamics and provide appropriate interventions for achieving better land management. The aim of this study is...Improving and understanding of land use and land cover change (LULC) can help in projecting future land use dynamics and provide appropriate interventions for achieving better land management. The aim of this study is to evaluate the status of induced small scale irrigation practices that affect the different land use changes over time in mai-dimu Kebele, Tigray, northern Ethiopia. Remote Sensing (RS), Geographic Information System (GIS) were used to determine the LULC dynamics with its land cover changes (1995-2015) by dividing in to three decades. In analyzing the accuracy assessment, the Kappa coefficient was found strong agreement between classified land cover classes and observed land cover/use with greater than 80% values. The coverage of cultivated land has high land use map cover with 28.45%, 31.83% and 27.74% in 1995, 2005 and 2015 respectively. No irrigation practice was observed in 1995 and 2005. However, in 2015 it was covered with 1.65 % of irrigated land. While the overall change difference from the year 1995 to 2015, was also by enlarge attributed to expansion of settlement, dam, cultivated land and irrigated lands increased positively with 700.20 ha, 124.02 ha, 33.48 ha and 181.98 ha respectively which subsequently decrease the land use of grass land (?336.48 ha), bush land (?561.52 ha), bare or rocky land (?68.94 ha) and forest land (?343.03 ha). Hence, inducing the irrigation practices could be additional yield production under dry season which later helps in improving the lively hood of the community.展开更多
The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing seve...The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.展开更多
Introduction:The presence of larger trees in semi-arid African savannas creates sub-habitats,which influences on herbaceous plant communities grown under their canopies differently from opened areas.Knowledge of seed ...Introduction:The presence of larger trees in semi-arid African savannas creates sub-habitats,which influences on herbaceous plant communities grown under their canopies differently from opened areas.Knowledge of seed banks accumulated in the soils over time beneath larger trees could facilitate the recovery of plant communities that might disappear due to sustained heavy grazing,prolonged fire,or other anthropogenic factors in semi-arid African savannas.However,the impact of larger trees on soil seed bank composition and its similarity with plant communities grown under their canopies are less understood in semi-arid African savannas.Therefore,we studied the effect of leguminous and non-leguminous tree species and their canopies on soil seed bank(SSB)composition and its similarity with understory vegetation(USV)in a semi-arid savanna of Ethiopia.Methods:We selected 20 matured trees from 3 dominant tree species,representing one leguminous(Acacia robusta Burch)and 2 non-leguminous tree species(Ziziphus spina-Christi and Balanites aegyptiaca(L.)Del),found in isolation,a total of 60 trees for this study.Under each selected individual tree,the species composition of USV were recorded using 1-m2 quadrat in four directions(north,south,east,and west)under the inside and outside tree canopies during the flowering stage.Similarly,soil samples in a 1-m2 quadrat were also collected under the inside tree canopies and their corresponding outside canopies,in each individual tree,for the determination of SSB composition,using a seed emergence method.Then,the soil was thoroughly mixed after removal of all roots and plant fragments,and spread over sand in plastic pots to a depth of 20 mm.The pots were placed at random in a glasshouse,examined every 3 days,for the first 2 months,and thereafter weekly for 6 months.A total of 960 soil samples were used for the determination of SSB composition during this study.Results:A total of 64 species were emerged from the SSB samples,of which 27 were grasses(19 annual and 8 perennial grasses),35 annual forbs and 2 woody species.Acacia robusta had a higher seedling density in the SSB compared to other tree species,whereas Z.spina-Christi had higher species diversity in the SSB than other tree species.Moreover,seedling density and species diversity were higher under the inside canopies than outside tree canopies.The mean similarity in species composition between the SSB and USV was low.However,it was higher under the leguminous trees than non-leguminous trees,and under the inside tree canopies than outside canopies.Conclusions:We found that mature tree species maintained a higher SSB species diversity and abundance under their canopies than the surrounding opened areas.Therefore,conservation of mature dominant tree species is of paramount importance for ecological stability and possible restoration of degraded semi-arid savannas under the changing climate and global warming.展开更多
文摘Groundnut (Arachis hypogaea L.) is an important cash crop for smallholder farmers in western Ethiopia. However, the yield of the crop is very low mainly because of strong soil acidity and poor soil fertility management. A study conducted to evaluate the effect of lime and mineral phosphorus fertilizer on yield components and yield of groundnut. The treatments consisted of three phosphorus rates (0, 46 and 92 kg P<sub>2</sub>O<sub>5·</sub>ha<sup>-1</sup>), three lime rates (0, 6, and 11 ton lime·ha<sup>-1</sup>), and three groundnut varieties (local cultivar, Werer-961, and Werer-963) was laid-out as a randomized complete design in a factorial arrangement with three replications. The corresponding rates of phosphorus applied per pot of soil (7 kg) amounted to 0, 107 and 215 mg kg·soil<sup>-1</sup> and those of lime amounted to 0, 14, and 26 g kg·soil<sup>-1</sup>. The analysis of variance showed that phenological characters, yield, and yield components significantly affected by interaction of variety, phosphorus, and lime. The highest dry pod yield produced by Werer-963 (2 kg dry pod yield·pot<sup>-1</sup>) in response to the application 11 t·ha<sup>-1</sup> lime and 46 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup>. However, Werer-961 produced medium (1.5 kg dry pod yield·pot<sup>-1</sup>) at 11 t·ha<sup>-1</sup> lime and 92 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup> and the local cultivar produced minimum (1 kg dry pod yield·pot<sup>-1</sup>) at the application of 11 t·ha<sup>-1</sup> lime and 92 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup>. In terms of phosphorus yield efficiency index, Werer-963 was highly efficient (index of 1.71), and Werer-961 was moderately efficient (index of 0.6). However, the local cultivar was inefficient (index of 0.04). It is at, in acidic soil of the study area Werer-963 is the best to be cultivated with application of lime 11 t·ha<sup>-1</sup> and 46 kg P<sub>2</sub>O<sub>5</sub>·ha<sup>-1</sup> fertilizer, followed by Werer-961. The results of this pot experiment have revealed that farmers in the study area need to switch to cultivating the improved varieties of groundnut rather than local variety with the application of high rates of lime and moderate amounts of phosphorus.
基金National Agricultural Technology Project(NATP)of Indian Council of Agricultural Research ICAR,Government of India,New Delhi for financial support
文摘The present study broadly focused on medicinal plant species collected from wild by the villagers for different purposes in the upper catchment of Dhauli Ganga in Nanda Devi Biosphere Reserve(NDBR),in the central Himalaya.A schedule based survey was conducted during the years 2003-2005 in 15 villages of Chamoli district part of the NDBR.Information was collected from collectors, vaidya(medicine man)and those dealing with domestication and marketing of the medicinal plants. The aim of the study was to understand the prioritiesed medicinal plants,their mode of collection and document their ethnobotanical uses by the Bhotiya tribal communities,in this world heritage site. During the survey,50 medicinal plants belonging to 31 families and 44 genera were documented.Out of these,70% were harvested from the wild,22% were cultivated and 8% were cultivated as well as wild harvested.Of the cultivated species,8% were found growing in the kitchen gardens and 14%in the agricultural fields.However,42%of the plants had their roots and rhizomes used followed by leaves (26%),seeds(10%),seed and leaf(8%),bark and whole plant(6%)and flower(1%).Most plants were reported to be used for rheumatism(16),followed by stomach disorder(14),cold and cough(11),and jaundice(9).Thirty three plants species were reported to have more than one therapeutic uses,while 17 species were reported to be used against single ailment.The distance of villages from road head was one of the factors contributing to the decline in the medicinal plant population in their natural habitats. The availability of medicinal plants increased with increase in distance from road head and also the peoples'dependence on them.Documentation of the traditional knowledge will help in conservation of knowledge and also opportunity for using it for future training and use.The result of this study will help in promoting sustainable cultivation and implementation in conservation protocol of those species,which are in the verge of extinction in this region.
文摘A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and three land use types. Analytical results of the collected surface layer soil samples showed significant (P ≤ 0.05) correlation of soil bulk density, OM and total N with elevation. In the lower elevation site (Indaslasie), soil OM content declined by about 43 and 52% compared with that of the two higher elevation sites (Cheguarcudo and Indamariam), respectively. Soil pH, exchangeable acidity, exchangeable Al, OM, total N and available phosphorus also exhibited significant (P ≤ 0.05) disparity across the three land use types of the area. Soils of the forest land were less acidic by 0.43 and 0.68 pH units than the cultivated and grazing lands, respectively. The soil OM content of the cultivated land was significantly lower by about 25 and 35% than the grazing and forest land soils, respectively. Available soil P status was low and showed significant correlations with pH (r = 0.65), exchangeable acidity (r = –0.58) and Al (r = –0.53). In general, the study results revealed altitude did not impose any significant effect in aggravating soil acidity whereas land use type affected significantly not only soil acidity but also the important soil fertility related parameters such as OM, total N and available P contents. Therefore, it can be suggested that besides to the usual acid soil management and/or reclamation practices, introducing proper land use management systems are of paramount importance.
文摘Plants in the alpine zone mainly depend on the reserved food materials stored in their rhizomes for the next growing season. We investigated the effect of mixed cropping （Phaseolus vulgaris L. var. Pinto） with four rhizomatous medicinal plants, i.e., Angelica glauca, Arnebia benthamii, Rheum emodi and Pleurospermum angelicoides as well as three levels of water stress treatment under two conditions （shade net and open field） on macronutrients （NPK） and biochemicals （carbohydrates and protein）. The experiment was conducted by completely randomized design （CDR）. The data were analyzed with ANOVA as well as CDR. The experimental results show that in all the species shade conditions with sever water stress （SSWS） increased the level of macronutrients （NPK）. However, （N） concentration was highest under shade with mixed cropping （SMIX）. Under SMIX, carbohydrate content was highest than open field control conditions （CONT）. This investigation results demon- strate that mixed cropping of medicinal plants with Phaseolus vulgaris could be a good livelihood option in the mountainous regions of Indian Central Himalaya. And the water-stress conditions along with mixed cropping could improve the biochemical constituents in the rhizome of these species.
文摘Compiled information on parkland agroforestry tree species in relation to diversity, tree management options and the challenges of the system is important for production and productivity, and biodiversity conservation through availing the required information which in turn has an implication to the sustainability of the system and climate change mitigation. So, the aim of this review paper is to compile information on parkland agroforestry practices of Ethiopia, particularly: on tree species diversity, their roles, management options available and challenges of the practice. Parkland agroforestry which is a system practiced by many local populations comprises the large part of agricultural landscapes in Ethiopia and is very important in different aspects such as;for food security, microclimate amelioration, economic benefits, environmental protection, household energy, household utensils, cultural values, traditional medicines, and fodder. There are many indigenous multipurpose tree species scattered on farmlands in Ethiopia, and the common one includes: Millettia ferruginea, Cordia africana, Ficus vasta, Ficus sur, Croton macrostachyus and Faidherbia albida. However, nowadays these trees are facing challenges like: expansion of exotic trees in the expense of the native ones, expansion of cash crops through removal of the parkland trees from the farm area, climate change, land shortage and tenure system which require high emphasis for the production and productivity as well as sustainability of the system especially, in this era of climate change;hence this system is one of climate change mitigation options.
文摘Improving and understanding of land use and land cover change (LULC) can help in projecting future land use dynamics and provide appropriate interventions for achieving better land management. The aim of this study is to evaluate the status of induced small scale irrigation practices that affect the different land use changes over time in mai-dimu Kebele, Tigray, northern Ethiopia. Remote Sensing (RS), Geographic Information System (GIS) were used to determine the LULC dynamics with its land cover changes (1995-2015) by dividing in to three decades. In analyzing the accuracy assessment, the Kappa coefficient was found strong agreement between classified land cover classes and observed land cover/use with greater than 80% values. The coverage of cultivated land has high land use map cover with 28.45%, 31.83% and 27.74% in 1995, 2005 and 2015 respectively. No irrigation practice was observed in 1995 and 2005. However, in 2015 it was covered with 1.65 % of irrigated land. While the overall change difference from the year 1995 to 2015, was also by enlarge attributed to expansion of settlement, dam, cultivated land and irrigated lands increased positively with 700.20 ha, 124.02 ha, 33.48 ha and 181.98 ha respectively which subsequently decrease the land use of grass land (?336.48 ha), bush land (?561.52 ha), bare or rocky land (?68.94 ha) and forest land (?343.03 ha). Hence, inducing the irrigation practices could be additional yield production under dry season which later helps in improving the lively hood of the community.
文摘The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.
文摘Introduction:The presence of larger trees in semi-arid African savannas creates sub-habitats,which influences on herbaceous plant communities grown under their canopies differently from opened areas.Knowledge of seed banks accumulated in the soils over time beneath larger trees could facilitate the recovery of plant communities that might disappear due to sustained heavy grazing,prolonged fire,or other anthropogenic factors in semi-arid African savannas.However,the impact of larger trees on soil seed bank composition and its similarity with plant communities grown under their canopies are less understood in semi-arid African savannas.Therefore,we studied the effect of leguminous and non-leguminous tree species and their canopies on soil seed bank(SSB)composition and its similarity with understory vegetation(USV)in a semi-arid savanna of Ethiopia.Methods:We selected 20 matured trees from 3 dominant tree species,representing one leguminous(Acacia robusta Burch)and 2 non-leguminous tree species(Ziziphus spina-Christi and Balanites aegyptiaca(L.)Del),found in isolation,a total of 60 trees for this study.Under each selected individual tree,the species composition of USV were recorded using 1-m2 quadrat in four directions(north,south,east,and west)under the inside and outside tree canopies during the flowering stage.Similarly,soil samples in a 1-m2 quadrat were also collected under the inside tree canopies and their corresponding outside canopies,in each individual tree,for the determination of SSB composition,using a seed emergence method.Then,the soil was thoroughly mixed after removal of all roots and plant fragments,and spread over sand in plastic pots to a depth of 20 mm.The pots were placed at random in a glasshouse,examined every 3 days,for the first 2 months,and thereafter weekly for 6 months.A total of 960 soil samples were used for the determination of SSB composition during this study.Results:A total of 64 species were emerged from the SSB samples,of which 27 were grasses(19 annual and 8 perennial grasses),35 annual forbs and 2 woody species.Acacia robusta had a higher seedling density in the SSB compared to other tree species,whereas Z.spina-Christi had higher species diversity in the SSB than other tree species.Moreover,seedling density and species diversity were higher under the inside canopies than outside tree canopies.The mean similarity in species composition between the SSB and USV was low.However,it was higher under the leguminous trees than non-leguminous trees,and under the inside tree canopies than outside canopies.Conclusions:We found that mature tree species maintained a higher SSB species diversity and abundance under their canopies than the surrounding opened areas.Therefore,conservation of mature dominant tree species is of paramount importance for ecological stability and possible restoration of degraded semi-arid savannas under the changing climate and global warming.
