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Understanding the performance of agroforestry woody species in controlled and free grazing systems is crucial for scaling up agroforestry practices. The objective of this study was to identify and evaluate the determinants of agroforestry woody species composition and regeneration in free and controlled grazing systems in the Ethiopian highlands. Household and field surveys were conducted on 83 and 171 households selected from controlled grazing (CG) and free grazing (FG) systems, respectively. Woody species performance was compared between the two grazing systems using independent T-test. Seemingly unrelated regression (SUR) was used to identify the factors determining woody species density/abundance, diversity and regeneration. Most trees were grown for fuel wood and timber rather than for fodder. CG users owned more diversified species and abundant regenerates and mature trees/shrubs than FG users. The SUR results showed that herd size, farmland size, fencing, plantation of seedlings, education, wealth, grazing system, farmland distance from homestead and slope were the major factors affecting the composition and regeneration of species. Specifically the SUR results per-household indicated that woody species regeneration was highly affected by grazing system. Fencing is the common underlying factor positively affecting species diversity, regeneration and density of mature trees. Homestead distance from road and number of planted seedlings significantly affected density of regenerates and mature trees. Density of mature trees and species diversity were significantly affected by agroecology and slope. Woody species diversity was significantly affected by education, wealth, farmland size and project participation. Our findings revealed that the scaling up of woody species in agroforestry requires not only CG and favorable agroecology but also matching of agroforestry options with household and farmland characteristics.

Land degradation is an endless challenge in the world. Thus, rehabilitation with organic amendments (OAs) is an urgent priority issue. The purpose of this study is to assess the effect of biochar and other OAs application on soil physicochemical properties and growth parameters of cover crops in greenhouse. Biochar, compost and manure were used as OAs. Soil samples were collected from nine random corners of 30 cm depth and composited. In each experiment, five treatments were considered (biochar, compost, manure, mixed and control) at 1:1 ratio of OAs and soil in a pot, with completely randomized design arrangement in triplicate. The field experiment was made on completely randomized block design and each block contained five 41 x 4 m plots assigned at random within the block and separated by 1 m walkways. OAs additions increased soil pH (5.69-8.13), cation exchange capacity (43.78-49.98 cmolc/kg), organic carbon (1.41-2.46%), organic matter (2.43-3.91%), total nitrogen (0.13-0.76%), available P (18.89-28.53 ppm) and (iron, Fe, manganese, Mn, copper, Cu and zinc, Zn) in comparison to non-treated soil. Tripartite treatments had the largest effect on the biomass of cover crops with 3.43 g fivefold of the control (0.7 g) in alfalfa and 4.54 g twofold of the control (2.07 g) in grass pea p ≤ 0.05. Both in field and greenhouse experiments combination of biochar and other OAs showed a better soil fertility increment and plant growth parameters. The study concluded that there is a synergistic effect in OAs on the soil fertility restoration and plant growth performance.

Genetic and metabolic diversities of rhizobacteria are the fundamental sources for their adaptation to cope with abiotic and biotic stresses in order to enhance growth and health of plants in the soil. Thus, this study was initiated to assess the genetic and metabolic diversities of rhizobacteria isolated from plants grown in degraded soil through BOX-PCR and partial sequencing of 16S rRNA genes. A total of eighty isolates were recovered and subjected to phenotypic profiling of carbohydrate and amino acid utilization, BOX PCR and 16S rRNA profiling. The phenotypic profiling showed remarkable metabolic versatility with Ochrobactrum spp, Pseudomonas spp and Klebsiella spp, and BOX-PCR showed greater discriminatory power for fingerprinting of rhizobacterial isolates with high degree of polymorphism. Bacillus spp showed the highest Simpson's diversity Index. The 16S rRNA genes sequence assigned the rhizobacteria to phyla Proteobacteria with Gammaproteobacteria and Alphaproteobacteria classes and Firmicutes with Bacilli class. The data also showed that the most dominant species were Pseudomonas and Ochrobactrum. Genetic and metabolic diversities of the rhizobacterial isolates reveal the potential of these microbes for plant growth improvement under water deficient soil after testing other inoculant traits., Microbiology; Bacillus species, Box-PCR, Ochrobactrum, phenotypic profiling, rhizobacteria

Despite the tremendous efforts exhibited by various utilities around the world during the past few years, there are still exceedingly many remote regions unreached by the electrical grid. For those regions, the enormous available potential of renewable energy resources is believed to be useful for the development of a stand-alone power supply system. This paper presents the modeling of a stand-alone hybrid system for the remote area of Ethiopia. A comparison of the economic performance of various scenarios of a stand-alone photovoltaic (PV)-wind hybrid system, with battery storage and diesel as a backup for electrifying remote rural areas, is presented. Therefore, a practical example, Kutur village of Awlio kebele of the Axum district, Ethiopia (which is 30 km away from the closest national grid) is considered for this research. Two electric load scenarios are estimated by considering the set of incandescent and efficient lamps for lighting for the 120 existing households. The above-mentioned solar radiation and wind speed are then used as an input to simulate the hybrid set-up for the high and low load estimation using HOMER software. The simulation result shows that the net present costs (NPC) corresponding to the high and low load scenarios is $262,470 and $180,731, respectively. Besides, an essential load forecasting is performed to see the effect of the increase in electric demand of the community on the required investment to install a stand-alone hybrid set-up. The NPC after load forecasting is found to be more than three folds of the NPC required for the reference year. In both cases, the simulation results indicate that using a stand-alone PV-wind hybrid system with battery storage and a diesel generator as a backup for electrifying Kutur village is cost-effective and comparable against the cost required for electrifying the village by extending the grid.

This study focuses on the production of biogas from slaughter house waste to generate optimal methane yield which has high calorific value under optimum temperature, pH and substrate proportion (blood, manure and undigested food material). In this study, two different kinds of experiment were done. The first experiment was carried out to determine the pH, total solid, volatile solid and ash content of each type of waste fermented independently at optimal temperature (35°C) and pH 7. The second experiment was done by mixing three types of wastes based on crossed D-optimal design expert software, a well-accepted statistical technique used to design and optimize the experimental process. It involves choosing the optimal experimental design and estimating the effect of the several variables which have 42 runs at different proportions of the substrates. After the experiment, the following parameters: methane content and volume of biogas, pH, temperature, total solid, volatile solids, and ash content of each type of waste were determined. From individual type of 0.351 sample waste (blood, manure and undigested content), maximum biogas production and methane composition obtained were 01, 71, 41 and 0%, 66% and 54%, respectively. From the 42 runs experimental result, the best optimal methane composition and biogas produced were 79.26% and 0.381 l/g, respectively. Optimal conditions included 20% blood, 20% manure, and 60% undigested content substrate at pH 7.88 and t 32.49°C temperature. Key words: Digester, biogas, methane, anaerobic digestion, abattoirs.

Genetic and metabolic diversities are sources of biodiversity that provides adaptation and could help to cope with environmental stresses. Thus, the study was initiated to assess the metabolic and genetic diversities of rhizobacteria from degraded soil through BOX-PCR and 16S rRNA sequencing. A total of eighty isolates were subjected to carbohydrate and amino acid utilization tests, BOX PCR and 16S rRNA profiling. The phenotypic profiling comprised utilization of C and N sources revealed metabolic versatility of the strains (14.29 to 100%). Accordingly, Ochrobactrum, Pseudomonas and Klebsiella spp expressed notable metabolic versatilities. BOX-PCR showed greater diversity with high degree of polymorphism. Simpson’s Index of Diversity (0.883) took the leading position with Bacillus species. The 16S rRNA showed that the isolates assigned to phyla Firmicutes (21.92%) and Proteobacteria (78.08%). The most dominant species were Pseudomonas (23%) and Ochrobactrum (21%). Metabolic and genetic diversities of the rhizobacteria reveal their potential for plant growth improvement under water deficient soil.

Faba bean is the most vital legume crop in Ethiopia, but abiotic stresses primarily soil acidity are an obstacle for its production. Soil acidity disturbs and potentially limits nitrogen-fixing symbiosis. The interruption of nitrogen fixation and faba bean rhizobia interaction as a result of soil acidity leads to decreasing crop production. Sole dependence on chemical fertilizers for agricultural growth would mean further loss in soil quality and increased environmental damage. Rhizobial species show off sizable metabolic abilities to mitigate abiotic and biotic stresses, and mechanisms in stress tolerance are advancing fast, offering a strong foundation for the choice and engineering of rhizobia and legume hosts with better tolerance to soil acidity accordingly. The vast efforts to pick bioinoculants that can restore nitrogen under acid-affected soils are producing competitive crop yields. The main challenge of using single-type bioinoculant in field application can lead to variable and inconsistent outcomes. Co-inoculation of compatible microbes with organic farming which does not involve use of synthetic pesticides and chemical fertilizers is an imperative element in sustainable agriculture. Therefore, the present chapter focuses on the field application of faba bean rhizobial inoculants in acidic soils as a promising potential input in organic farming system. Moreover, the mechanism of N2 fixation and plant growth promotion systems under severe salt, drought, acidity, temperature, and heavy metal stresses is also highlighted.

The ornithological role of lake Hashengie and 10 selected reservoirs have been studied from January to February, 2012 in Tigray, Ethiopia. Birds were surveyed using total and Block count methods from suitable vantage points. Bird species diversity, dominance, and vegetation cover were estimated. A total of 22,845 birds of 67 species belonging to 19 families were recorded. Maximum numbers of species were recorded in Lake Hashengie (65) followed by Hzaeti Wedi Cheber (38) and minimum was recorded in Mai Della reservoir (15). Significant difference in bird species were recorded between the two sites which have maximum number of bird species (Mann-Whitney Test: W = 778.5, P = 0.00). The migratory status of bird species showed that 47 (70 %) were migrants and the rest 20 (29%) were residents. Vulnerable species, Ferruginous duck, Aythya nyroca, in Lake Hashengie and globally near threatened species, Rouget’s rail Rougetius rougetii in Teghane and Ruba Feleg reservoirs were recorded. The highest vegetation cover (65%) was estimated in Tsnkanet. We conclude that the reservoirs and the natural lake intended for irrigation harbor a number of bird species and are an important foraging, breeding, roosting and nesting grounds for the birds. Key words: Migratory, reservoirs, residential, Hashengie, threatened, vulnerable, Tigray, Ethiopia.

Avifauna studies and conservation efforts in Africa have focused on protected areas. Habitats outside of protected areas also support a variety of bird species. A survey of avian diversity was conducted in northern Ethiopia in three fragmented woodland areas dominated by human activities, adjacent to Important Bird Areas. Overall, 85 bird species belonging to 32 families were sighted in the three localities, including five species endemic to Ethiopia and eight Afrotropical highland biome species. Such diverse bird assemblages in the localities show the significance of habitats outside of protected areas for future avian research and conservation in Ethiopia. These habitats need to be protected.

To elucidate the action mechanism of environmental androgenic chemicals on fish reproductive activity by transient stimulation in heavily polluted areas, individuals of the hermaphrodite fish Kryptolebias marmoratus were injected once with six concentrations of methyltestosterone (MT) (0.1, 1, 5, 10, 50, and 100 μg/g BW) intraperitoneally. The fish were sampled at intervals of 7, 15, and 30 days after a single injection. At 7 days after injection, mature oocytes were not observed in the MT-exposed groups except for the group exposed to 0.1 μg MT, while testicular development was not remarkably different between any of the groups. Also, at 7 days after injection, hepatic estrogen receptor α (ERα) and vitellogenin (VTG) mRNA abundance decreased significantly in the MT-exposed groups despite no significant difference in plasma 17β-estradiol (E2) levels between any of the groups. This significant difference in VTG mRNA between the control and the MT-exposed groups persisted until 30 days after injection, although ERα mRNA abundance was not statistically different between any groups at 30 days after injection. Our results clearly show that a single injection of MT inhibits ovarian development rather than testicular development in the hermaphroditic gonad of K. marmoratus. Furthermore, our results demonstrate that a single injection of MT interfered with hepatic VTG mRNA synthesis mediated by the suppression of hepatic ERα mRNA transcription.

The increase in energy price and environmental concerns focused attention on the need for industrial process improvement and development of alternative energy sources such as ethanol fuel. Ethiopia, in its GTP 2, has planned to produce 320,268 m3 of ethanol leaving around 3.8 million m3 of vinasse as a by-product.,having very high biological oxygen demand (BOD), chemical oxygen demand (COD), and other pollutant properties which necessitate distillery plants to deal with its treatment and reuse. The purpose of this thesis work was to optimize the anaerobic treatment vinasse for substantial decrease of its BOD and COD while producing methane gas and to evaluate potential of vinasse as an alternative source of energy. Vinasse sample was taken from Metehara sugar factory distillery plant. The combined effect of temperature and pH on biogas production and reduction of organic load such as COD, BOD and VS was studied in this work. Accordingly, vinasse samples that were treated at temperature of 35 oC and initial pH of 7.25 for hydraulic retention time of 20 days on anaerobic digestion system has produced 34.68 ml of CH4/g COD while COD, BOD and VS concentration were reduced by 64, 76 and 52.77 % respectively. The Composition of biogas was 81 % CH4, 14 % CO2, 2 % O2, 3 % other and 1 PPM H2S. The minimum amount of biogas production (21.05 ml of CH4/g COD) and low removal efficiency of COD, BOD and VS (30.8, 45, and 25.4 % respectively) were observed at samples treated with temperature of 30 oC and pH of 6.5. From the design of UASB reactor, the expected amount of energy generated from anaerobic digestion of vinasse of Metehara sugar factory distillery plant is 1.99 x 108 KJ/day, which is equivalent to 10850 KWH.. It was noted that vinasse is a suitable feedstock for anaerobic digestion and can be a good source of alternative green energy and protect the environment from pollution.

Androgens, for example testosterone, are major hormones that affect male courtship activity, territorial activity, sexual dimorphism, and reproductive tactics; they reach, and are maintained at, a sufficient level to express such sexual traits at the appropriate time for reproductive success. This study examined the effects of androgen levels (testosterone and 11-ketotestosterone) on male brood cycling with two distinct reproductive phases (i.e. court- ship and parental phases) of a paternal brooding blenny Rhabdoblennius nitidus. Our study showed that time spent on courtship behaviour and androgen levels decreased with progress of brood cycling. In addition, time spent on courtship behaviour of males administered cyproterone acetate, an anti-androgen, was shorter than that of control males. These results indicate that the brood cycling is affected by the change in androgen levels. The study also showed that androgen levels decreased after acquisition of the eggs, irrespective of available spawning space in the nests. This result suggests that the presence of eggs themselves may be a trigger for the shift from the courtship phase to parental phase.

The generally accepted wisdom that large carnivores cannot survive in human dominated landscapes does not hold true in Ethiopia. The present work reports on spotted hyena abundance and distribution in and around three National Forest Priority Areas in Tigray, northern Ethiopia. Calling stations were used to assess spotted hyena abundance and distribution in and outside the protected areas. We assessed human tolerance towards predators and factors responsible for livestock loss. The response outside the forest was significantly higher. Predators, disease and theft were the factors responsible for livestock loss. The presence of a guard, the construction of an enclosure and the presence of dogs were used to mitigate livestock depredation. The majority of the respondents had a positive attitude towards predator conservation. Our data suggest that spotted hyenas in our study area are more abundant and widely distributed in human-dominated landscapes than in natural forest areas, probably because of better scavenging opportunities from human waste and livestock. (C) 2014 Deutsche Gesellschaft fur Saugetierkunde. Published by Elsevier GmbH. All rights reserved.

Effective and sustainable control of Schistosomamansoni infection requires identifying subpopulations that are at risk of infection. A cross-sectional epidemiological survey was conducted in children of four primary schools in Raya Alamata District of Ethiopia to determine the prevalence and intensity of infection, and index of potential contamination of intestinal schistosomiasis. Fecal samples of 500 (266 males and 234 females) subjects aged 6-19 years were processed using Kato Katz thick smear field technique. Questionnaire survey was also deployedto assess associated risk factors among infected children. Out of the examined children, 101(20.2%) were infected by S. mansoni. The prevalence of infection differed significantly among the age groups (÷2= 6.93; P

長崎大学学位論文 [学位記番号]博(生)甲第248号 [学位授与年月日]平成23年3月18日