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Impact of Land Cover Change on Water Quality and Stream Flow in Lake Hawassa Watershed of Ethiopia

Agricultural Sciences 2014年第8期5卷 647-659页

作者： Wolka Kebede Mengistu Tefera Taddese Habitamu tolera alemayehu Wondo Genet College of Forestry and Natural Resources Hawassa University Hawassa Ethiopia

Quantifying the hydrologic response of land use/land cover change (LULCC) is of paramount importance to improve land management. This study was carried out to analyze the effect of LULCC on water quality and quantity. LULCC of the watershed in 1986, 1999 and 2011 was analyzed from Landsat satellite images using supervised classification. Time series and point data were collected from the upper and lower sections of Wedesa, Wesha and Hallo Rivers. Water quality parameters (turbidity, suspended solid (SS), total dissolved solid (TDS), pH, electric conductivity (EC), total organic carbon (TOC), ammonia, nitrate and phosphate) were analyzed in the laboratory. A considerable decline in forest and an increase in woodland were observed in the watershed during the indicated periods. Turbidity, SS, TDS and EC were significantly higher (P < 0.05) in the lower section of the rivers compared to the upper ones. Ammonia, nitrate and phosphate were higher in the lower section of some rivers compared to the upper ones. In general, water quality in the upper watershed of the three rivers was better than the lower one with respect to considered parameters, which might be related to the observed LULCC. Most water quality parameters varied (P < 0.05) seasonally in both the upper and lower sections of the rivers. Despite the irregular rainfall pattern and increased water consumption from the catchment, the annual discharge of the Tikur-Wuha River to Lake Hawassa shows an increasing trend. We concluded that the discharge is not only related to the upstream LULCC but also to the management of the Cheleleka wetland. However, further investigation is required to determine the dominant factors affecting inflow discharge to Lake Hawassa.

关键词： Discharge Ethiopia Lake Hawassa Water Quality Wetland

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Pleiotropy Structures Plant Height and Seed Weight Scaling in Barley despite Long History of Domestication and Breeding Selection

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Plant Phenomics 2023年第1期5卷 85-93页

作者： Tianhua He Tefera tolera Angessa Chengdao Li Western Crop Genetics Alliance Agricultural SciencesCollege of ScienceHealthEngineering and EducationMurdoch UniversityMurdochWAAustralia Agriculture and Food Department of Primary Industries and Regional DevelopmentSouth PerthWAAustralia

Size scaling describes the relative growth rates of different body parts of an organism following a positive *** and crop breeding often target the scaling traits in the opposite *** genetic mechanism of the size scaling influencing the pattern of size scaling remains ***,we revisited a diverse barley(Hordeum vulgare L.)panel with genome-wide single-nucleotide polymorphisms(SNPs)profile and the measurement of their plant height and seed weight to explore the possible genetic mechanisms that may lead to a correlation of the two traits and the influence of domestication and breeding selection on the size *** height and seed weight are heritable and remain positively correlated in domesticated barley regardless of growth type and *** structural equation modeling systematically evaluated the pleiotropic effect of individual SNP on the plant height and seed weight within a trait correlation *** discovered seventeen novel SNPs(quantitative trait locus)conferring pleiotropic effect on plant height and seed weight,involving genes with function in diverse traits related to plant growth and *** disequilibrium decay analysis revealed that a considerable proportion of genetic markers associated with either plant height or seed weight are closely linked in the *** conclude that pleiotropy and genetic linkage likely form the genetic bases of plant height and seed weight scaling in *** findings contribute to understanding the heritability and genetic basis of size scaling and open a new venue for seeking the underlying mechanism of allometric scaling in plants.

关键词： breeding scaling Plant

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Rangeland water requirement satisfaction index under rainfall variability and predicting future rainfall scenarios: implication for availability of feed resources

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Ecological Processes 2017年第1期6卷 264-272页

作者： Hassen M.Ahmed Zewdu K.Tessema Adugna tolera Diriba Korecha School of Animal and Range Sciences College of Agriculture and Environmental SciencesPO Box 138Dire DawaEthiopia School of Animal and Range Sciences Hawassa UniversityPO Box 222HawassaEthiopia Famine Early Warning Systems Network PO Box 1090Addis AbabaEthiopia School of Animal and Range Sciences College of Agriculture and Environmental SciencesHaramaya UniversityPO Box 1632Dire DawaEthiopia

Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid ***,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing *** a result,the potentials of most rangelands in semi-arid ecosystems affect the ***,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in Mieso,Jigjiga,and Shinile districts under pastoral conditions of ***:The base period rainfall data(1984–2015)was obtained from the National Meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using MarkSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).Mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and Minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall ***:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in Mieso(P<0.05),Jigjiga(P<0.001),and Shinile(P<0.001)pastoral ***,short and long rainy seasons had positive association(P<0.001)with rangeland WRSI,especially in Jigjiga and Shinile pastoral *** base period rainfall as well as the predicted annual rainfall showed variability in amount and distribution in all studied districts in pastoral areas of ***:The mean annual rainfall anomaly is correlated with the rangeland ***,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–***,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.

关键词： LEAP software Pastoralist Rangeland water requirement Trend analysis

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Salinity tolerance in barley during germination——homologs and potential genes

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2020年第2期21卷 93-124页

作者： Edward MWANDO Tefera tolera ANGESSA Yong HAN Chengdao LI Western Barley Genetics Alliance College of ScienceHealthEngineering and EducationMurdoch UniversityMurdochWA 6150Australia Western Australian State Agricultural Biotechnology Centre Murdoch UniversityMurdochWA 6150Australia Department of Primary Industries and Regional Development 3 Baron-Hay CourtSouth PerthWA 6151Australia

Salinity affects more than 6%of the world’s total land area,causing massive losses in crop *** inhibits plant growth and development through osmotic and ionic stresses;however,some plants exhibit adaptations through osmotic regulation,exclusion,and translocation of accumulated Na+or Cl-.Currently,there are no practical,economically viable methods for managing salinity,so the best practice is to grow crops with improved *** is the stage in a plant’s life cycle most adversely affected by ***,the fourth most important cereal crop in the world,has outstanding salinity tolerance,relative to other cereal ***,we review the genetics of salinity tolerance in barley during germination by summarizing reported quantitative trait loci(QTLs)and functional *** homologs of candidate genes for salinity tolerance in Arabidopsis,soybean,maize,wheat,and rice have been blasted and mapped on the barley reference *** genetic diversity of three reported functional gene families for salt tolerance during barley germination,namely dehydration-responsive element-binding(DREB)protein,somatic embryogenesis receptor-like kinase and aquaporin genes,is *** all three gene families show great diversity in most plant species,the DREB gene family is more diverse in barley than in wheat and *** to this review,a convenient method for screening for salinity tolerance at germination is needed,and the mechanisms of action of the genes involved in salt tolerance need to be identified,validated,and transferred to commercial cultivars for field production in saline soil.

关键词： Genetics Barley Quantitative trait locus(QTL) Germination Salinity tolerance Homologous gene Diversity

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Effects of Inclusion of Different Levels of Ethiopian Thyme (Thymus schimperi Ronniger) as Natural Additive on Chemical Composition and In Sacco Dry Matter Degradability of Total Mixed Ration and Feed Ingredients

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Open Journal of Veterinary Medicine 2022年第11期12卷 155-169页

作者： Feyissa Kera Mengistu Urge Getachew Animut Adugna tolera Department of Animal and Range Sciences College of Agriculture Salale University Fitche Ethiopia Department of Animal and Range Sciences College of Agriculture Haramaya University Dire Dawa Ethiopia Ethiopian Agricultural Transformation Agency Addis Ababa Ethiopia Department of Animal and Range Sciences College of Agriculture Hawassa University Hawassa Ethiopia

This study evaluated the effects of the inclusion of Ethiopian thyme (Thymus schimperi Ronninger) to natural pasture hay (NPH), noug seed cake (NSC), wheat bran (WB) and total mixed ration (TMR) on the chemical composition and in Sacco dry matter (DM) degradability of the feeds. The Thyme plant used for the study was collected from Dinsho and Tarmaber districts in the highlands of Ethiopia. Samples of the TMR and NPH, WB and NSC with or without thyme were divided into two parts and ground to pass through 1 mm screen for chemical analysis and 2 mm screen for in sacco DM degradability. The TMR contained 50% NPH, 32.5% WB, 14% NSC, 3% molasses and 0.5% common salt. The feed ingredients (NPH, WB and NSC) and the TMR were incubated without thyme or with thyme substituting the diet at 8%, 16% and 24% levels of treatments. The chemical composition of all the feeds differed significantly (P In sacco rumen dry matter degradability of NPH, WB, NSC and TMR was increased (P in sacco DM degradability of NPH at all incubation hours was higher (P Thymus schimperi plant up to a level of 24% DM in feed can reasonably stimulate the growth and activity of the certain rumen microbes that promoted an improvement in ruminal DM degradability of the diet with the thyme inclusion.

关键词： Natural Additive Feed Degradability Thymus schimperi Medicinal Plant Phytochemicals

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Human-climate induced drivers of mountain grassland over the last 40 years in Sidama, Ethiopia: perceptions versus empirical evidence

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Ecological Processes 2018年第1期7卷 392-407页

作者： Denbeshu Debeko Ayana Angassa Aster Abebe Ashenafi Burka Adugna tolera College of Agriculture School of Animal and Range SciencesHawassa UniversityP.O.Box 05HawassaEthiopia Wondo Genet College of Forestry and Natural Resource School of Natural Resources and Environmental StudiesHawassa UniversityHawassaEthiopia Department of Animal Science and Production Botswana University of Agriculture and Natural ResourcesPrivate Bag 0027GaboroneBotswana

Background:Mountain grasslands are globally important *** are considered as heritage sites with“outstanding values”to ecological communities by adding a further“layer and support to the existing protection measures.”However,mountain grasslands are increasingly under threat from human activities and impacts of climate ***:Using satellite imagery,we studied land use/land cover(LULC)patterns between 1973 and *** interviews consisting of 240 households for comparison and field data collection were conducted for accuracy ***:Five categories of LULC types were identified from the image classification that included forestland,grassland,shrubland,bushland,and agricultural *** 1973 and 2015,the forestland,grassland,and shrubland covers were declined by 15.9%,53.6%,and 41.0%,*** contrast,bushland and agricultural land were increased by 169%and 647%,*** overall LULC classification accuracies for the four reference years ranged from 77.6 to 86.5%with Kappa statistic of 0.69 to *** majority of respondents(92.5%)mentioned that the cover of forestland outsized the other land use land cover types followed by grassland in the ***:The stated indicators of land use/land cover changes linked to the impact of climate change were decline in milk yield and crop production,spread of livestock diseases,degradation of grazing lands,and change in the timing of *** results of the study suggest that human-climate related components were major drivers of land use/land cover dynamics that demand for proper management and conservation of mountain grassland ecosystem in Sidama South Ethiopia.

关键词： Land use/land cover Landsat Remote sensing Change detection Mountain grassland Sidama Household survey

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Climate forcing of tree growth in dry Afromontane forest fragments of Northern Ethiopia:evidence from multi-species responses

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Forest Ecosystems 2019年第2期6卷 132-148页

作者： Zenebe Girmay Siyum J.O.Ayoade M.A.Onilude Motuma tolera Feyissa Pan African University Life and Earth Sciences (including Health and Agriculture) Institute University of Ibadan Ibadan Nigeria Wondo Genet College of Forestry and Natural Resource Hawassa University P.O. Box 128 Shashemene Ethiopia Department of Geography University of Ibadan Ibadan Nigeria Department of Agricultural and Environmental Engineering University of Ibadan Ibadan Nigeria

Background: Climate-induced challenge remains a growing concern in the dry tropics, threatening carbon sink potential of tropical dry forests. Hence, understanding their responses to the changing climate is of high priority to facilitate sustainable management of the remnant dry forests. In this study, we examined the long-term climate-growth relations of main tree species in the remnant dry Afromontane forests in northern Ethiopia. The aim of this study was to assess the dendrochronological potential of selected dry Afromontane tree species and to study the influence of climatic variables (temperature and rainfall) on radial growth. It was hypothesized that there are potential tree species with discernible annual growth rings owing to the uni-modality of rainfall in the region. Ring width measurements were based on increment core samples and stem discs collected from a total of 106 trees belonging to three tree species (Juniperus procera, Olea europaea p. cuspidate and Podocarpus falcatus). Thesubsp. collected samples were prepared, crossdated, and analyzed using standard dendrochronological methods. The formation of annual growth rings of the study species was verified based on successful crossdatability and by correlating tree-ring widths with rainfall. Results: The results showed that all the sampled tree species form distinct growth boundaries though differences in the distinctiveness were observed among the species. Positive and significant correlations were found between the tree-ring widths and rainfall, implying that rainfall plays a vital role in determining tree growth in the region. The study confirmed the formation of annual growth rings through successful crossdating, thus highlighted the potential applicability of dendroclimatic studies in the region. Conclusions: Overall, the results proved the strong linkage between tree-ring chronologies and climate variability in the study region, which further strengthens the potential of dendrochronological stud

关键词： Climate-growth relationship Climate change Dry Afromontane forest Restoration Tree-ring width

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在提高白梨（Pyrus bretschneideri）授粉方面本土蜜蜂优于外来蜜蜂

在提高白梨（Pyrus bretschneideri）授粉方面本土蜜蜂优于外来蜜...

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作者： tolera Kumsa Gemeda 邵有全武文卿杨慧鹏黄家兴吴杰

不同蜜蜂种类的觅食行为是影响其在不同作物中授粉效率的关键因素。大部分梨的品种都是自交不亲和的因此它们完全是异花授粉,然而在中国对于本土的中华蜜蜂和外来的西方蜜蜂对梨树的访花偏好性了解很少。我们在自然条件下的梨树生长地...

不同蜜蜂种类的觅食行为是影响其在不同作物中授粉效率的关键因素。大部分梨的品种都是自交不亲和的因此它们完全是异花授粉,然而在中国对于本土的中华蜜蜂和外来的西方蜜蜂对梨树的访花偏好性了解很少。我们在自然条件下的梨树生长地区对于这两种蜜蜂对梨树授粉的差异做了比较分析。结果表明这两种蜜蜂在倾向搜集的花粉反面具有显著的变化,相对于西方蜜蜂,中华蜜蜂在早上出去觅食的时间更早并且收集的更多的花粉。基于收集花粉量的数据,西方蜜蜂显示出了变化的偏好性:在观察的第一天它们主要集中在梨树上觅食,但是在另外一些天中它们则也收集其他地方植物的花粉,与之相对的是中华蜜蜂则是一直在梨树中收集花粉,并不会去其它植物的花中收集花粉。因此在自然条件下对梨树花粉收集的过程中中华蜜蜂优于西方蜜蜂,利用中华蜜蜂能够增加梨树的授粉。本研究支持进一步增加且保持中华蜜蜂对梨树和其它本土作物的授粉,此外,有必要发展可选择的授粉管理技术,即利用西方蜜蜂为梨树授粉。

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脱粉器和糖水饲喂可以提高蜜蜂对非优选花粉的收集能力

脱粉器和糖水饲喂可以提高蜜蜂对非优选花粉的收集能力

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作者： tolera Kumsa Gemeda 李继莲罗术东杨慧鹏靳婷婷黄家兴吴杰

梨（Pyrus bretschneideri）具有自交不亲和、依赖异花授粉才能坐果的特点。蜜蜂（Apis mellifera）被认为是梨树最重要的授粉者。然而,只有少量的花朵被授粉会造成梨树很低的坐果率。在这里,我们试验了以下假设:（i）蜂群经过处理后,...

梨（Pyrus bretschneideri）具有自交不亲和、依赖异花授粉才能坐果的特点。蜜蜂（Apis mellifera）被认为是梨树最重要的授粉者。然而,只有少量的花朵被授粉会造成梨树很低的坐果率。在这里,我们试验了以下假设:（i）蜂群经过处理后,蜜蜂的收集能力增强。（ii）收集的花粉主要来自试验目标作物。（iii）这个方法可以快速有效的评估蜂群经过不同处理后授粉的能力:（1）使用脱粉器（2）联合使用脱粉器和糖水（3）单独使用糖水（4）不使用糖水和脱粉器的对照组。试验结果表明蜂群经过处理后可以显著的增加其花粉收集能力（p＜0.05）。联合使用糖水和脱粉器组（19.4g）以及脱粉器单独使用组（16.4g）平均花粉收获量高于糖水单独使用组（12.85g）和对照组（8.7g）。因此,联合使用脱粉器和糖水是提高花粉收集量最有效的处理方式,其他的处理方式（单独使用糖水和单独使用脱粉器）也是有效的。这个研究表明了蜜蜂蜂群经过处理后可以增加其对非优选花粉的收集能力。

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