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1.
Environmental Science and Pollution Research - This empirical study investigates the dynamic effects of economic freedom on economic growth and air quality for Pakistan over the period...  相似文献   
2.
The structure and advancement of woody vegetation was studied in a semi-arid rangeland of southern Ethiopia under three land-use systems (communal land, a government ranch and a traditional grazing reserve enclosure) and along a distance gradient (near, middle and far) from water sources. A total of 54 woody plant species were identified. Based on the subjective opinions of the pastoralists, 85% of the identified woody plants have forage values to livestock. Cadaba farinsoa, Ormocarpum trichocarpum, Rhus natalensis, Acacia brevispica, Cordia gharaf and Hibiscus sparseaculeatus were reported to have fair to good palatability. Tree equivalent (TE) density of all woody plants combined was greater (P <0.01) in the government ranch (1) 188 TE ha(-1)) and the communal land (1083 TE ha(-1)) than in the traditional grazing reserve (419 TE ha(-1)), whereas this did not vary significantly (P >0.05) along the distance gradient from water. The most important encroaching woody plant species in the study areas were in descending order: Commiphora africana, Acacia drepanolobium, A. brevispica, Acacia. tortilis, Grewia tembensis and Lannea floccosa. The density of individual encroaching woody plant species along the distance gradient from water was not consistent. All encroaching woody species had the highest TE density in the communal land. The prevalence of these species followed the pattern of intensity of use within the communal grazing area. Most of the woody species had the highest abundance in the height class >0-2m regardless of land use and distance gradient from water. This study investigated the advance of severe woody encroachment in the communal and government sites as well as along the distance gradient from water. Some of the important contributing factors that can be suggested are heavy grazing pressure (in both the communal and government sites), expansion of cultivation and reduced mobility of livestock due to settlement of the pastoralists in the communal land.  相似文献   
3.
For the determination of 15 potentially toxic elements (V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Hg, and Pb) in plant and sediment samples of the Akaki River, Ethiopia, inductively coupled plasma–mass spectrometry, inductively coupled plasma–optical emission spectrometry, and a RA-915+ mercury analyzer were applied. Sediment and plant samples were mineralized using a closed-vessel microwave-assisted digestion system. The elemental concentrations varied considerably in plant and sediment samples. The minimum concentration was observed for known toxic elements (As, Hg, and Cd) while the highest concentration was observed for the elements of relatively low toxicity Zn, Mn, and Fe. The concentration of Cr, Fe, Pb, Zn, and As in Swiss chard surpassed the maximum permissible levels at specific sites. At some of the sites, the sediment quality guidelines are surpassed for Cu, Zn, and Pb.  相似文献   
4.
Journal of Material Cycles and Waste Management - The use of agricultural crop residues and animal manure for soil amendment is limited in most part of Ethiopia because of high competition for the...  相似文献   
5.
The Ethiopian Rift Valley Lakes host populations of edible fish species including Oreochromis niloticus, Labeobarbus intermedius and Clarias gariepinus, which are harvested also in other tropical countries. We investigated the occurrence of six heavy metals in tissues of these fish species as well as in the waters of Lake Koka and Lake Awassa. Both lakes are affected by industrial effluents in their catchments, making them ideal study sites. Mercury concentrations were very low in the water samples, but concentrations in the fish samples were relatively high, suggesting a particularly high bioaccumulation tendency as compared with the other investigated metals. Mercury was preferentially accumulated in the fish liver or muscle. It was the only metal with species-specific accumulation with highest levels found in the predatory species L. intermedius. Lower mercury concentrations in O. niloticus could be attributed to the lower trophic level, whereas mercury values in the predatory C. gariepinus were unexpectedly low. This probably relates to the high growth rate of this species resulting in biodilution of mercury. Accumulation of lead, selenium, chromium, arsenic and cadmium did not differ between species, indicating that these elements are not biomagnified in the food chain. Values of cadmium, selenium and arsenic were highest in fish livers, while lead and chromium levels were highest in the gills, which could be related to the uptake pathway. A significant impact of the industrial discharges on the occurrence of metals in the lakes could not be detected, and the respective concentrations in fish do not pose a public health hazard.  相似文献   
6.
Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-13968-6  相似文献   
7.
Child‐ and youth‐friendly spaces have become a common feature of emergency humanitarian provision. This study reports on the outcomes of child and youth learning centres (CYLCs) in Ethiopia's Buramino Camp established for those fleeing conflict in Somalia. Eighty‐five youths completed baseline assessments shortly after arrival and follow‐up assessments three to six months later. Caregivers of 106 younger children completed similar appraisals. 693 children attending the CYLCs completed pre‐ and post‐educational assessments, which indicated major gains—significant at p<0.0001—in both literacy (younger children, t=9.06; youth, t=13.87) and numeracy (younger children, t=13.94; youths, t=17.10). Children's CYLC attendance increased reports of met needs among caregivers (t=2.53, p<0.05) and youths (t=2.57, p<0.05), and, among caregivers but not youths, significantly moderated protection concerns (t=2.39, p<0.05, and t=?1.90, p=0.06, respectively). There was general improvement in psychosocial well‐being over time for all children; CYLC attendance predicted greater reductions in reported difficulties only among younger children (t=2.51, p<0.05).  相似文献   
8.
Prosopis juliflora, which is an alien tree species in Ethiopia, has invaded over 360,500 ha of land in the Afar region of the country and is threatening pastoral livelihoods. We conducted a contingent valuation study to assess rural households’ willingness to contribute in cash and labor to mitigate P. juliflora invasion in three districts of Afar. Results show that about 84% of the respondents prefer an intervention involving complete eradication of P. juliflora. The lower and upper bound median willingness to contribute to this intervention were 9.97 and 13.42 USD/household/year in cash and 30 and 43 days/household/year in labor. Off-farm income and P. juliflora invasion levels on pasturelands are among the factors affecting willingness to contribute to the mitigation of P. juliflora invasion. Incentives to local people and having a proper institutional setup that involves local culture and institutions are important for mobilizing people on a voluntary basis for mitigation of P. juliflora invasion.  相似文献   
9.
Poverty, hunger and demand for agricultural land have driven local communities to overexploit forest resources throughout Ethiopia. Forests surrounding the township of Humbo were largely destroyed by the late 1960s. In 2004, World Vision Australia and World Vision Ethiopia identified forestry-based carbon sequestration as a potential means to stimulate community development while engaging in environmental restoration. After two years of consultation, planning and negotiations, the Humbo Community-based Natural Regeneration Project began implementation—the Ethiopian organization’s first carbon sequestration initiative. The Humbo Project assists communities affected by environmental degradation including loss of biodiversity, soil erosion and flooding with an opportunity to benefit from carbon markets while reducing poverty and restoring the local agroecosystem. Involving the regeneration of 2,728 ha of degraded native forests, it brings social, economic and ecological benefits—facilitating adaptation to a changing climate and generating temporary certified emissions reductions (tCERs) under the Clean Development Mechanism. A key feature of the project has been facilitating communities to embrace new techniques and take responsibility for large-scale environmental change, most importantly involving Farmer Managed Natural Regeneration (FMNR). This technique is low-cost, replicable, and provides direct benefits within a short time. Communities were able to harvest fodder and firewood within a year of project initiation and wild fruits and other non-timber forest products within three years. Farmers are using agroforestry for both environmental restoration and income generation. Establishment of user rights and local cooperatives has generated community ownership and enthusiasm for this project—empowering the community to more sustainably manage their communal lands.  相似文献   
10.
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