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41.
Fentahun Abere Yehualashet Belete Alemayehu Kefalew Teshome Soromessa 《Journal of Sustainable Forestry》2017,36(6):604-622
This study estimates the carbon stock of Banja Forest which is natural and dry Afromontane forest type in Banja District, northwest of Ethiopia. A systematic sampling method was used to identify each sampling point through the Global Positioning System. A total of 63 plots measuring 20 × 20 m were employed to collect tree species and soil data. Losses on ignition and the Walkley–Black method were used to estimate biomass and soil carbon stock, respectively. The carbon stock of trees was estimated using an allometric equation. The results revealed that the total carbon stock of the forest was 639.87 t/ha whereas trees store 406.47 t/ha, litter, herbs, and grasses (LHGs) 2.58 t/ha and soil 230.82 t/ha (up to 30 cm depth). The carbon pools’ carbon stock variation with altitude and slope gradients were not significant (p > 0.05) which was similar to other previous studies. The Banja Forest is a reservoir of high carbon and thus acts as a great sink of the atmospheric carbon. It can be concluded that the Forest plays a role in climate change mitigation. Hence, it should be integrated with reduced emission from deforestation and degradation (REDD+) and the clean development mechanism (CDM) of the Kyoto Protocol to catch monetary benefits. 相似文献
42.
The prevalence and antimicrobial resistance pattern of Salmonella isolates was determined from apparently healthy slaughtered cattle at Debre Zeit (Ethiopia). A total of 323 cattle were examined
for the presence of Salmonella in faeces, mesenteric lymph nodes, abdominal and diaphragmatic muscles. Salmonellae were cultured from 23 (7.1%) of the animals.
Salmonellae were isolated from 2 (3.1%) and 3 (4.5%) of 65 pooled faecal and mesenteric lymph node samples, respectively.
Nine (2.8%) abdominal muscle and 10 (3.1%) diaphragmatic muscle samples (n = 323 of each) were contaminated by Salmonella. About 60% of the serovars identified in the abdominal and diaphragmatic muscles were also detected from faeces and mesenteric
lymph node samples. The five different serovars isolated were Salmonella mishmarhaemek (48%), S. typhimurium (20%), S. enteritidis (12%), S. guildford (12%) and S. dublin (48%). The antimicrobial resistance profiles of 25 of the Salmonella isolates with 17 antimicrobials showed that 52% (13/25) of them were resistant to three or more antimicrobials. Both strains
of Salmonella (S. mishmarhaemek and S. typhimurium) showed multiple resistance to ampicillin, sulfamethoxazole and ticarcillin.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
43.
The seroprevalence of Babesia bigemina and Babesia bovis antibodies in non-vaccinated cattle was monitored on a South African ranch. The main objective was to assess the endemic stability to bovine babesiosis in cattle maintained under relaxed tick-control measures. Cattle were bled at the age of 7, 8, 10, 17, 20 and 30-120 months and the sera tested for the presence of antibodies using the indirect fluorescent antibody (IFA) test. None of the animals were positive to B. bovis. Seroprevalence of B. bigemina antibodies was 46, 70, 90, 92, 54 and 82% in the various age classes, respectively. Endemic stability was therefore reached by the time the calves were 9 months old. The high seroprevalence of B. bigemina was probably due to the high vector tick population on the ranch, which would have encouraged frequent transmission of B. bigemina. An endemically stable situation to B. bigemina could therefore be achieved merely by adopting a tick-control method that allows a reasonable number of ticks on cattle rather than relying entirely on intensive tick control and vaccination. 相似文献
44.
Regassa A 《The Onderstepoort journal of veterinary research》2001,68(1):41-45
A study was conducted to identify and determine burdens of ticks infesting Borana cattle in the Borana Province of Ethiopia. Rhipicephalus pulchellus, Rhipicephalus pravus, Rhipicephalus muhsamae, Rhipicephalus praetextatus, Rhipicephalus evertsi evertsi, Amblyomma gemma, Amblyomma variegatum, Amblyomma cohaerens, Amblyomma lepidum, Hyalomma truncatum, Hyalomma marginatum rufipes and Boophilus decoloratus were identified on the cattle. Their burdens ranged from 658-1,554 with a mean of 1,205 ticks per animal. Out of the total 6,025 ticks collected, about 82% were R. pulchellus, followed by R. pravus (about 8%) and A. gemma (5%). The other nine species of ticks accounted for only 5% of the total burdens. It is suggested that a strategic tick control method, aimed mainly at reducing the R. pulchellus burdens, with the objective of allowing a reasonable number of ticks to remain on cattle for the maintenance of endemic stability to tick-borne diseases be instituted. 相似文献
45.
Alemayehu Lemma DVM PhD Merga Bekana DVM FRVCS PhD Horst Juergen Schwartz MSc PhD Thomas Hildebrandt DVM 《Journal of Equine Veterinary Science》2006,26(1):18-22
The ovarian activities of 7 jennies were studied by serial ultrasonography during seasons of higher and lower sexual activity to determine if follicular development also corresponds to this pattern. The current study showed a seasonal pattern of ovarian activities related to the local environmental factors associated with each season rather than photoperiod, which is the widely known environmental cue determining seasonality in most equines. Jennies produced large numbers of follicles (11.3 follicles) during the long rainy season, compared with the 7.3 and 9.6 follicles during the dry and short rainy seasons, respectively. However, production of larger preovulatory follicles (37.8 ± 1.7 mm vs 31.0 ± 2.7 mm of the dry and 33.2 ± 2.7 mm of the long rainy seasons) and higher incidence of ovulation (77.8%) occurred during the short rainy season. Jennies had shorter interovulatory intervals during the season of higher (short rainy) than the season of lower (dry season) sexual activity. The short rain transition is characterized by higher follicular activity compared with the long rainy transition, indicating the presence of additional factors stimulating ovarian activity other than the mere availability of forage during the short rainy season. 相似文献
46.
In Ethiopia, forests near churches, are the last remnant forest patches. These forests are currently under threat, probably due to diminishing areas of the forest itself and repeated grazing for extended periods by cattle. We assessed the effect of livestock exclusion on the regeneration of four indigenous tree species in two church forests. The four species have a high abundance and socioeconomic value, but limited regeneration in the two forests. We investigated the effect of grazing and trampling on seed germination, seedling survival, and seedling growth. Livestock grazing had a strong negative effect on germination, seedling growth and mortality. In fenced plots, more seeds germinated, seedling survival was higher and seedlings grew faster. Seed germination was higher inside the forest than in the adjacent open area for all species. Seedling survival was not different between forest interior and open fields, except for unfenced plots in the open fields where survival was lower because of the higher grazing pressure. In unfenced plots, no seedlings survived until the end of the year, indicating that grazers destroyed the seedling bank in and around the forest. The significant interaction between fencing and species on seed germination and seedling survival revealed that the magnitude of damage due to grazing can vary with species. 相似文献
47.
Alemayehu Hido Motuma Tolera Paul H. Evangelista 《Journal of Sustainable Forestry》2020,39(6):620-634
ABSTRACT A study was conducted in South Omo Zone, Ethiopia with the aim of assessing the population status of the frankincense tree Boswellia neglecta and investigating its resin essential oil chemical composition. The status of populations of B. neglecta was assessed by examining the density, abundance, frequency, dominance, importance value index, and population structure. Resin sample was analyzed for the physicochemical properties. The composition of the essential oil was analyzed with Gas Chromatography-Mass Spectrometry. The high values of density, abundance, frequency, dominance, and importance value index for B. neglecta showed the potential of the tree for bulk resin collection. Boswellia neglecta had a bell-shaped diameter distribution indicating a hampered regeneration. The B. neglecta resin had a moisture content of 2.68%, ash content of 0.99%, pH of 5.7, and oil yield of 5.92%. The resin possessed good quality as compared to resins in other reports. The essential oil was optically active (?31.6° at 23.2°C). The essential oil contained several compounds, but 71.1% of the composition were formed mainly from methyl oleate, methyl linoleate, methyl palmitate, which have not been reported from B. neglecta. Sustainable management must be enacted since the agro-pastoralist mode of life hinders regeneration of the species and its resin resources. 相似文献
48.
Fikadu Reta Alemayehu Georg Frenck Leon van der Linden Teis Nørgaard Mikkelsen Rikke Bagger Jørgensen 《Genetic Resources and Crop Evolution》2014,61(1):151-161
The projected future climate will affect the global agricultural production negatively, however, to keep abreast of the expected increase in global population, the agricultural production must increase. Therefore, to safeguard the future crop yield and quality, the adaptive potential of crops to environmental change needs to be explored in order to select the most productive genotypes. Presently, it is unknown whether cereal crops like spring barley can adapt to climate stressors over relatively few generations. To evaluate if strong selection pressures could change the performance of barley to environmental stress, we conducted a selection experiment over five plant generations (G0–G4) in three scenarios, where atmospheric [CO2] and temperature were increased as single factors and in combination. The treatments represented the expected environmental characteristics in Northern Europe around year 2075 [700 ppm CO2, 22/17 °C (day/night)] as well as a control mimicking present day conditions (390 ppm CO2, 19/12 °C). Two different barley accessions, a modern cultivar and an old landrace, were evaluated in terms of yield and biomass production. In all treatments representing future environmental scenarios, the G4-generation of selected plants did not improve its reproductive output compared to the G0-generation, as G4 produced less seeds and had a lower yield than unselected plants. These results indicate that barley might not respond positively to rapid and strong selection by elevated [CO2] and temperature, contrary to previous results from oilseed rape. The two barley accessions analyzed presented almost the same response pattern in a given treatment, though the modern cultivar had the highest yield in the climate scenarios, while the landrace was superior in yield under present day climate conditions. 相似文献
49.
Yayeh Bitew Getachew Alemayehu Enyew Adego Alemayehu Assefa 《Journal of plant nutrition》2020,43(12):1824-1839
AbstractTraditional short-term diversification of annual crops for the purpose of improving soil fertility and food security is a common practice in Ethiopia. However, the best cropping systems have not been selected yet though field research. Experiments were conducted for two years with an objective of establishing sustained finger millet based short term cropping sequence in two major finger millet producing areas of Ethiopia. The experiments were laid out in a split-plot arrangement with six precursor crops (haricot bean, maize, sweet lupine, niger seed, wheat, and teff) as a main plot factor, where determined residues were retained in the main plot after harvesting and two nitrogen fertilizer levels (30 and 60?kg ha?1) applied for finger millet as sub-plots with three replications. Soil analysis result examined immediately after finger millet harvest showed a significant effect of precursor crops and nitrogen fertilizer rates on soil properties. Planting finger millet following lupine increased the soil organic carbon, total nitrogen and cation exchange capacity by 17.37%, 65.50%, 26.15%, respectively, over planting finger millet following teff. Use of different amount of nitrogen fertilizer likely contributed to observed differences in residual soil nutrients. Accordingly, finger millet following lupine with the addition of 60?kg ha?1 nitrogen fertilizer gave significantly higher finger millet grain yield (3.24 tone ha?1) and relative production (22.37%) and economic (40.7%) efficiency. This system with their high sustainability and multiple benefits can be readily accepted by the farming community. 相似文献
50.
Up to 100 single plant derived lines of 18 barley landraces, collected from 18 localities of six barley growing regions of
Ethiopia were studied for two years at Holetta, Ethiopia for variation in five quantitative traits; scald severity, earliness,
plant height, 1000 grain weight, and leafiness. The relative latent period in the adult plant stage to barley leaf rust, a
good measure for partial resistance, was assessed on the landrace lines at Wageningen, The Netherlands. The observed variation
between and within landraces was very large for all traits. The magnitude of variation was so large that most, if not all,
plants within a landrace had a different genotype. The landraces also varied in the degree of variation. Some landraces, 1726
and 3288 for instance, were more variable for most or all traits than other landraces such as 208925 and 212938. Days to heading
and scald severity were significantly (P = 0.01) correlated with altitude, r being 0.66 and - 0.65, respectively. Resistance
to scald and leafiness also increased with altitude. On average landraces became later, more resistant to scald and more leafy
the higher the altitude of collection. This associated complex of traits could be an adaptation to the wetter and cooler conditions
at higher altitudes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献