• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.399-405
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• 2016

Poor subsistence farmers who live in a semi-arid area of northern Ethiopia build irrigation systems to overcome water shortages. However, there is a high risk of malaria transmission when increased standing water provides more favorable habitats for mosquito breeding. This is a serious problem because there are many barriers to malaria control measures and health care systems in the area. Using a causal loop diagram and computer simulations, the author attempted to visually illustrate positive and negative feedbacks between mosquito and human populations in the context of Simret, which is a small village located in northern Ethiopia and is generally considered a malaria-free area. The simulation results show that the number of infectious mosquitos increases to 17,215 at its peak, accounting for 3.5% of potentially dangerous mosquitos. At the same time, the number of sick people increases to 574 at its peak, accounting for 15% of local population. The malaria outbreak is controlled largely because of a fixed number of vulnerable people or local population that acts as an intermediate host.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.282-283
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• 2019

• Asian Journal of Business Environment
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• v.10 no.4
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• pp.29-34
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• 2020

Purpose: Town of Woldia, a semi-arid region in the Northern Wollo region of Ethiopia, faces water supply shortage in general, though the town possesses a running stream of clean water throughout the year. This study is aimed at analyzing the possibility of using rainwater for water scarcity and non-potable water needs of the Woldia University. A careful study and analysis have been made to assess the feasibility of using rainwater in place of the tap water supply. Research design and methodology: This study was done inside the main campus of Woldia University located in Woldia town. The runoff water from the roof of buildings was studied, by the time of rainfall in the town. Also, the budget needed for implementing a rainwater harvesting system was calculated. Results: The findings of the study clearly indicates that the requirements of the water to use for flushing, cleaning, and washing toilets in the administrative buildings and classrooms can be satisfied by using rainwater as an alternative to tap water. Conclusion: Based on the results the study finds it is benefitable for the Woldia University to install the rainwater harvesting system at the earliest to solve the water problems prevailing in the current situation.

• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.25-36
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• 2020

Area exclosure is a widely practiced intervention of restoring degraded lands though its impact in sequestering terrestrial and soil carbon is scanty. The study was initiated to investigate the effect of exclosure of different ages on carbon sequestration potential of restoring degraded dryland ecosystems in eastern Tigray, northern Ethiopia. Twelve plots each divided into three layers were randomly selected from 5, 10 and 15 years old exclosures and paired adjacent open grazing land. Tree and shrub biomasses were determined using destructive sampling while herb layer biomass was determined using total harvest. The average total biomass obtained were 13.6, 24.8, 27.1, and 55.5 Mg ha^-1 for open grazing, 5 years, 10 years, and 15 years exclosures respectively. The carbon content of plant species ranged between 48 to 53 percent of a dry biomass. The total carbon stored in the 5 years, 10 years and 15 years age exclosures were 39 Mg C ha^-1, 46.3 Mg C ha^-1, and 64.6 Mg C ha^-1 respectively while in the open grazing land the value was 24.7 Mg C ha^-1. Carbon stock is age dependent and increases with age. The difference in total carbon content between exclosures and open grazing land varied between 14.3-40 Mg C ha^-1. Although it is difficult to extrapolate this result for a longer future, the average annual carbon being sequestered in the oldest exclosure was about 2.7 Mg C ha^-1 yr^-1. In view of improving degraded area and sequestering carbon, area exclosures are promising options.

• Journal of Ecology and Environment
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• v.44 no.3
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• pp.178-184
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• 2020

Background: Geladas (Theropithecus gelada), endemic to Ethiopia, are distributed closely related to the escarpments and gorge systems of the country, and large populations are found in the Simien Mountain National Park. This study was conducted in Eastern Tigray, Northern Ethiopia, from February 2018 to August 2019 in order to determine population size and composition of geladas. Total count method was used to estimate the population structure of geladas. Observations of the group of geladas based on body size and morphological characteristics were used to classify age and sex categories of the population. SPSS Version 20 was used to analyze the data. Chi-square test was used to compare sex ratio of geladas and population size among the counting sites between wet and dry seasons. Results: A total of 112 and 99 individual of geladas were counted during wet and dry seasons, respectively. Of the average gelada population recorded in this study, 11.4% were adult males, 30.3% were adult females, 12.8% were sub-adult males, 25.6% were sub-adult females, and 19.9% were unidentified juveniles. However, there was no statistically significant difference among the various age and sex groups of geladas counted during wet and dry season (χ² = 2.6, DF = 4, P > 0.05). Variations of group size along seasons were observed in this study. Sex ratio of adult male to adult female was 1:2.6 and 1:2.7 during the dry and wet seasons, respectively. Conclusion: Very small gelada population size was recorded in the current study. An average of 105.5 geladas was recorded during the study period. As this is the first report of gelada population in escarpments of Eastern Tigray, population trend of the geladas cannot decide based on the current study.

• Safety and Health at Work
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• v.12 no.1
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• pp.51-56
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• 2021

Background: Neck pain is a major public health problem among sewing machine operators working in textile factories. Even though the textile industries are growing in number in Ethiopia, but there is a dearth of published studies on the prevalence of neck pain. Therefore, this study was aimed to assess the prevalence and associated factors of neck pain among sewing machine operators of garment factories in Mekelle city. Method: An institutional-based cross-sectional study design was implemented among 297 sewing machine operators' working in garment factories in Mekelle city. A systematic random sampling technique was used. Data were collected through interviews and analyzed using Statistical Package for Social Science version 23. Finally, variables with 95% confidence interval (CI): p < 0.05 in the multivariate analysis were significantly declared. Results: Two hundred ninety-seven sewing machine operators were enrolled, with 98.7% response rates. In this study, the 12-month prevalence rate of neck pain was found to be 42.3% (95% CI: 36.6%-47.9%), and variables like such as break time [adjusted odds ratio (AOR): 5.888, 95% CI: (2.775-12.493)], working hours per day [AOR: 6.495, 95% CI: (2.216-19.038)], static posture [AOR: 4.487, 95% CI (1.640-12.275)], and repetitive activity [AOR: 4.519, 95% CI:(2.057-9.924)] were associated with neck pain. Conclusion: In this study, neck pain is a major public health problem. Continuous work without break time, working greater than 8 hours per day, sitting in the same position for greater than 2 hours, and high repetitive activities were found significantly associated with neck pain. Owners and governmental bodies need to focus on developing preventive strategies and safety guidelines.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.292-303
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• 2021

Studies that relate the structure of tropical regrowth vegetation to soil properties are generally lacking in the literature. This study proposes three indices for assessing the structural regeneration of secondary forests. They are: (1) the tree diameter class, (2) the plant life form and (3) the woody/herbaceous plants ratio indices. They were applied to assess the regeneration status of forest regrowth vegetation (aged 1-10 years), derived savanna regrowth vegetation in south western Nigeria, and to secondary forests in different stages of succession in Columbia and Venezuela, Bolivia, Mexico in South and Central America and semi-arid savanna in Ethiopia and seasonal deciduous forest successional stages in India. In all the cases, the indices increased with increasing age of regrowth vegetation and hence, with increasing structural complexity of regenerating vegetation. The tree diameter class index increased from 32.1% in a 9-year secondary forest to 69.0% in an 80-year-old secondary forest in Columbia and Venezuela and from 0.4% in a 1-year fallow to 20.9% in 10-year regrowth vegetation in southwestern Nigeria. In semi-arid savanna in northern Ethiopia, the woody/herbaceous plants ratio index increased from 18.1% in a 5-year protected grazing enclosure to 75.1% in 15-year protected enclosure, relative to the status of 20-year enclosure. The indices generally had correlations of 0.6-0.90 with species richness and Simpson's/Margalef's species diversity, implying that they are appropriate measures of ecosystem development over time. The proposed indices also had strong and positive correlations with soil organic carbon and nutrients. They are therefore, significant indicators of fertility status.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.427-437
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• 2019

Background: Climate change is believed to be continuously affecting ticks by influencing their habitat suitability. However, we attempted to model the climate change-induced impacts on future genus Rhipicephalus distribution considering the major environmental factors that would influence the tick. Therefore, 50 tick occuance points were taken to model the potential distribution using maximum entropy (MaxEnt) software and 19 climatic variables, taking into account the ability for future climatic change under representative concentration pathways (RCPs) 4.5 and 8.5, were used. Results: MaxEnt model performance was tested and found with the AUC value of 0.99 which indicates excellent goodness-of-fit and predictive accuracy. Current models predict increased temperatures, both in the mid and end terms together with possible changes of other climatic factors like precipitation which may lead to higher tick-borne disease risks associated with expansion of the range of the targeted tick distribution. Distribution maps were constructed for the current, 2050, and 2070 for the two greenhouse gas scenarios and the most dramatic scenario; RCP 8.5 produced the highest increase probable distribution range. Conclusions: The future potential distribution of the genus Rhipicephalus show potential expansion to the new areas due to the future climatic suitability increase. These results indicate that the genus population of the targeted tick could emerge in areas in which they are currently lacking; increased incidence of tick-borne diseases poses further risk which can affect cattle production and productivity, thereby affecting the livelihood of smallholding farmers. Therefore, it is recommended to implement climate change adaptation practices to minimize the impacts.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.73-83
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• 2019

Background: Habitat selectivity and ecology of freshwater fishes were studied in two selected streams and their junction point which consist a total of 39 microhabitats. The aims of this study were to describe the habitat preference and its availability to fish assemblage, as well as ecology, habitat use, and habitat characteristics. Methods: We collected fish with backpack electrofishing three times during August 2013, December 2013, and March 2014. Using a variation partitioning approach of R software, we studied the relationship of fish abundances with stream type, habitat type, and abundance of key macroinvertebrate taxa. Results: A total of 6554 fishes representing four species belonging to the family Cyprinidae were caught. A higher total fish abundance was recorded from Gereb Tsedo (4870; 74.3%) than from Elala stream (1684; 25.7%). Taking both streams together, the overall total relative fish abundance was significantly higher in pools (53%) than in runs (35%) and in riffles (12%) at P < 0.05. Species-wise comparisons showed that 71%, 15%, 13%, and 1% of the pool fish community were occupied by Garra blanfordii, Garra ignestii, Garra dembecha, and Garra aethiopica, respectively. Stream type, habitat type, and key macroinvertebrate taxa each explained a significant proportion of the variation in fish abundance. Based on the variation partitioning approach, fish abundance was higher in Gereb Tsedo stream (P < 0.01). Moreover, fish abundance increased with pool habitat type (P < 0.01) and with availability of key macroinvertebrate taxa (P < 0.01). Conclusion: Fish abundance differed between stream types, among habitats and among key macroinvertebrate taxa availability. Among the factors, habitat type was the most important driving factor behind variation among fish abundances, and pool supports the highest fish abundance.

• Fisheries and Aquatic Sciences
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• v.27 no.8
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• pp.501-514
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• 2024

Fishes are found in different lentic and lotic aquatic ecosystems. Determining the composition of fish communities is a crucial component of water quality evaluations and conservation strategies in flowing rivers. The present study is carried out to investigate fish species diversity, richness, and abundance in two second-order streams: Gereb Tsedo (GTS) and Elala in the Tekeze sub-basin. We collected fish with backpack electrofishing during August and December 2013 and March 2014. Fish species richness and the total number of species per stream and per microhabitat were calculated for each stream. Species diversity for each site was calculated using the Shannon index of diversity using the standard formula H' = -Σpi ln (pi). Diversity data among habitats and streams were compared using one-way analysis of variance (ANOVA) and Tukey post hoc comparisons, using the statistical software package STATISTICA 11. A total of 6,554 specimens representing four species: Garra blanfordii, Grra ignestii, Garra dembecha and Garra aethiopica, were caught. They are all indigenous riverine fish species of the family Cyprinidae. Fish abundance was significantly higher in GTS than Elala stream (t-test, t = 1.444, df = 3, p < 0.05). Across the two streams, the overall relative fish abundance was higher in pools, with 53%, followed by runs and riffles with 35% and 12%, respectively. Garra blanfordii was dominant in pools while G. aethiopica was the least dominant. Stream and habitat types were likely the more important driving factors behind the observed patterns of diversity, although the impact of other, not evaluated variables cannot be excluded. Most likely, the observed patterns do not represent a signature of fish dispersal limitation given that almost all species were widely distributed across the study area.