Understanding drivers of changes in land use/land cover (LULC) is essential for modeling future dynamics or development of management strategies to ameliorate or prevent further decline of natural ...resources. In this study, an attempt has been made to identify the main drivers behind the LULC changes that had occurred in the past four decades in Munessa-Shashemene landscape of the south-central highlands of Ethiopia. The datasets required for the study were generated through both primary and secondary sources. Combination of techniques, including descriptive statistics, GIS-based processing, and regression analyses were employed for data analyses. Changes triggered by the interplay of more than 12 drivers were identified related to social, economic, environmental, policy/institutional, and technological factors. Specifically, population growth, expansion of cultivated lands and settlements, livestock ranching, cutting of woody species for fuelwood, and charcoal making were the top six important drivers of LULC change as viewed by the local people and confirmed by quantitative analyses. Differences in respondents’ perceptions related to environmental (i.e., location specific) and socioeconomic determinants (e.g., age and literacy) about drivers were statically significant (
P
= 0.001). LULC changes were also determined by distances to major drivers (e.g., the further a pixel is from the road, the less likelihood of changes) as shown by the landscape level analyses. Further studies are suggested targeting these drivers to explore the consequences and future options and formulate intervention strategies for sustainable development in the studied landscape and elsewhere with similar geographic settings.
Soils represent the largest carbon pool and play important roles for carbon storage for prolonged periods in agroecosystems. A number of studies were conducted to quantify soil organic carbon (SOC) ...worldwide. The objective of this review was to evaluate organic carbon stocks, dynamics and restoration in soils of agroecosystems in Ethiopia. Soil data from 32 different observations, representing four different agroecosystems, were analysed. The mean SOC stocks in the four agroecosystems varied and ranged from 25.66 (sub-humid agroecosystem) to 113.17 (humid mid-highland agroecosystems) Mg C ha-1 up to one meter depth. The trend of mean SOC followed (in descending order): humid mid-highland (113.17 Mg C ha-1) > per-humid highland (57.14 Mg C ha-1) > semi-arid (25.77 Mg C ha-1) > sub-humid (25.66 Mg C ha-1). Compared with soils of tropical countries, those in Ethiopian agroecosystems contained low SOC storage potential. This might be associated with differences in measurement and analysis methods as 53.1% of the studies employed the Walkley-Black Method, which is known to underestimate carbon stocks in addition to ecological and management effects. However, shifts of land management from rain-fed to irrigation farming systems exhibited progress in the improvement of mean SOC storage potential. The analyses showed that farming systems involving irrigation sequestered more carbon than rain-fed farm systems. The mean SOC in the various agricultural land uses followed the following trend (in descending order): agroforestry (153.57 Mg C ha-1) > grazing land (34.61 Mg C ha-1) > cereal cultivation (24.18 Mg C ha-1). Therefore, the possible solutions for improvement of organic carbon stocks would be implementation of appropriate restoration strategies based on agroecosystems.INTERNATIONAL JOURNAL OF ENVIRONMENT Volume-6, Issue-1, Dec-Feb 2016/17, page: 1-22
Farmers in the highlands of Ethiopia often plant Eucalyptus on their farmlands. However, growing Eucalyptus, especially on farm- lands suitable for crop production has become a great concern due to ...its alleged long-term site effects. Our study was conducted at Koga water- shed, Mecha District, northwestern Ethiopia to investigate whether crop- lands afforested with Eucalyptus camaldulensis Dehnh. can be restored for annual crop production after tree harvest. We compared growth and yield of two agricultural crops, barley （Hordeum vulgate L.） and finger millet （Eleusine coracana （L.） Gaertn.）, grown in clear-felled stands of E. camaldulensis and continuously cultivated croplands at twelve paired farmlands under a conventional farming system. Plant height and dry matter production were evaluated as indices of crop growth, while grain weight was evaluated as an index of crop yield. Crop growth and yield measurements averaged over all farmlands differed between land-use types. For both crops, plants grown on clear-felled stands were taller than on croplands. Dry matter production and yield were also significantly greater in crops cultivated on clear-felled stands. Cropland aboveground and belowground dry matter productions were lower by 31.8 and 25.4% for barley and 32.8% and 37% for finger millet, respectively. Clear-felled stands gave an average yield of 2.91 t.ha-1 for barley and 3.27 t.ha-1 for finger millet while cropland gave a yield of 1.97 and 2.31 t.ha-1 for barley and finger millet, respectively. Farmers also responded that farm plots on former eucalypt plantations showed greater crop growth and yield thandid continuously cultivated croplands. Farmers perceived that Eucalyptus plantations improved soil fertility and they preferred clear-felled stands for crop production and wished to plant Eucalyptus on their farmlands. Our results suggest that conversion of agricultural lands to Eucalyptus plantations can increase post-felling yields of cereal crops.
Models under a set of scenarios are used to simulate and improve our understanding of land use/land cover (LULC) changes, which is central for sustainable management of a given natural resource. In ...this study, we simulated and examined the possible future LULC patterns and changes in Munessa-Shashemene landscape of the Ethiopian highlands covering four decades (2012–2050) using a spatially explicit GIS-based model. Both primary and secondary sources were utilized to identify relevant explanatory variables (drivers) and LULC datasets for the model. Three alternative scenarios, namely Business As Usual (BAU), Forest Conservation and Water Protection (FCWP) and Sustainable Intensification (SI) were used. The simulated LULC map of 2012 was compared with the actual for model validation and showed a good consistency. The results revealed that areas of croplands will increase widely under the BAU scenario and would expand to the remaining woodlands, natural forests and grasslands, reflecting vulnerability of these LULC types and potential loss of associated ecosystem service values (ESVs). FCWP scenario would bring competition among other LULC types, particularly more pressure to the grassland ecosystem. Hence, the two scenarios will result in severe LULC dynamics that lead to serious environmental crisis. The SI scenario, with holistic approach, demonstrated that expansion of croplands could vigorously be reduced, remaining forests better conserved and degraded land recovered, resulting in gains of the associated total ESVs. We conclude that a holistic landscape management, i.e. SI, is the best approach to ensure expected production while safeguarding the environment of the studied landscape and elsewhere with similar geographic settings. Further study is suggested to practically test our framework through a research for development approach in a test site so that it can be used as a model area for effective use and conservation of our natural resources.
Display omitted
•Future land use/land cover changes under sets of scenarios are examined using model.•Areas of croplands will expand to the forests under Business As Usual scenario.•Strict implementation of current policies will bring competition among land uses.•Sustainable Intensification scenario ensure expected production while safeguarding the environment.
The germination requirements of seeds of 20 leguminous species were studied in three experiments. In the first experiment, seeds were subjected to mechanical scarification, sulphuric acid and boiling ...water treatments. In the second experiment, they were treated with dry heat at 60, 80 and 100°C. In the third experiment, seeds were placed at different temperature regimes (10, 15, 20, 25 and 30°C) on a thermogradient. Sulphuric acid treatment improved germination in all the species while mechanical scarification improved germination in 18 out of 20 species. Boiling water treatment improved germination in 15 species but proved to be lethal to five species. Similarly, germination was significantly improved in 11 out of 16 species treated with dry heat. Germination was faster and higher at both 25°C and 30°C and the optimum temperature for germination was between 20°C and 30°C for all the species. Mechanical scarification, sulphuric acid and boiling water treatments as well as dry heat were effective to overcome seed coat imposed dormancy in the species studied. It was not possible to recommend a treatment which is equally effective for all the species. However, boiling water is a practical method for achieving rapid, uniform and high germination except in five of the species for which it proved to be lethal. In the latter case, either mechanical scarification or sulphuric acid treatment should be used. Seeds of Millettia ferruginea should be sown when they are fresh to get high germination as they tend to lose their viability during storage. Results from the present study show that once the dormancy in leguminous species with hard seed coats is broken, the seeds germinate in wide ranges of temperature.
• The molecular diversity of arbuscular mycorrhizal (AM) fungi colonizing roots of Prunus africana and of AM fungal spores obtained from baiting cultures of indigenous soils from two dry afromontane ...forests of Ethiopia was investigated. • The internal transcribed spacer (ITS) rDNA region from colonized roots and single spores of three AM fungal spore types was amplified, cloned and sequenced using AM fungal specific primers. • Phylogenetic analysis using the 5.8S rDNA data set revealed that 109 of the sequences obtained belong to members of the Glomeromycota. Subsequent 5.8S/ITS2 rDNA sequence analysis indicated high AM fungal diversity and dominance of Glomus types. Twenty sequence types belonged to the Glomeraceae and one each to the Diversisporaceae and Archaeosporaceae. Two of the three spore types were identified as Glomus etunicatum and Glomus mosseae. • Twenty of the AM fungal types identified are new to Ethiopia and to science. The AM fungal community differed between the two sites studied.
Ethiopia is one of the largest bamboo resource bases in Africa. However, a dearth of reliable data on bamboo resources has impeded the proper management of bamboo forests and limited their potential ...in providing more socio-economic and environmental benefits. Therefore, the objective of this study was to examine the socio-economic importance of
O. abyssinica
in the Lower Beles River Basin, north-western Ethiopia. Datasets were collected from both primary and secondary sources. A combination of techniques: descriptive statistics and qualitative analysis, was employed for data analysis. The results showed that a total of 10 services were identified as important socio-economic uses of bamboo. Bamboo as construction material, traditional furniture, income, food, and medicine were the top five uses of bamboo as perceived by respondents and confirmed through quantitative analysis. Differences in views among respondents of different ethnic backgrounds concerning some socio-economic uses of bamboo, namely food, medicine, and musical instruments, were statistically significant. Despite the wide range of services bamboo provides, the management practice is so unsustainable and rudimentary, which impedes the sustainability of the resource and livelihood of people relying on it. Therefore, concerned bodies should provide the priority attention that the resource deserves to curve the unsustainability spiral as well as properly utilize and conserve the bamboo resource.
Besides direct water abstraction, natural water scarcity in semi-arid and arid regions may be further exacerbated by human-assisted changes in vegetation composition, including the invasion by ...non-native plant species. Water abstraction by the invasive tree Prosopis juliflora and by the native Senegalia senegal was compared in the dry Great Rift Valley, Ethiopia. Transpiration rates were quantified using the heat ratio method on six trees each of P. julifora and S. senegal, growing adjacent to each other in the same environment. Water use for P. juliflora trees ranges from 1 to 26 L/day (an average of 4.74 ± 1.97), and that of S. senegal trees from 1 to 38 L/day (an average of 5.48 ± 5.29 during two study years). For both species, soil heat, latent heat, and soil moisture status influenced the rates of sap flow of trees; in addition, water use by P. juliflora trees was related to vapor pressure deficit; the higher the vapor pressure deficit, the higher the water abstraction by P. juliflora. Stand densities of pure P. juliflora and S. senegal were 1200–1600 trees and 400–600 trees per ha, respectively. At the stand scale, P. juliflora consumed approximately 6636 L/day/ha (transpiration: 242 mm per year) and S. senegal stands consumed 2723 L/day/ha (transpiration: 87 mm per year). That is, P. juliflora stands consumed three times more water than S. senegal stands, because of two reasons: (1) P. juliflora stands are denser than S. senegal stands, and denser stands consume more water than less dense stands, and (2) P. juliflora is evergreen and uses water all year-round, while S. senegal sheds its leaves during the peak dry seasons. Our findings suggest that, compared to S. senegal, P. juliflora invasion results in severe impacts on groundwater resources of the drylands of Ethiopia, with direct and indirect consequences to ecosystem services and rural livelihoods.
Display omitted
•At the stand scale, P. juliflora consumes approximately 6,636 L/day/ha (transpiration: 242 mm per year) and S. senegal stands consume 2,723 L/day/ha (transpiration: 87 mm per year).•P. juliflora stands are multi-stemmed and denser than S. senegal stands, and which foster P. juliflora to consume more water than S. senegal.•P. juliflora invasion resulted in severe impacts on water resources of the dry lowland areas of Ethiopia, with direct and indirect consequences to rural livelihoods.
Bamboo forests, which are an integral part of the eco-system and an important source of socio-economic life for rural communities in the vast savannah lowlands of Ethiopia, are experiencing ...significant changes. Therefore, examining bamboo forest cover changes and identifying responsible drivers for the changes are of the greatest importance for sustainable management of these useful resources. This study was intended to examine the spatio-temporal bamboo forest dynamics in the Lower Beles River Basin, north-western Ethiopia. A combination of pixel-based hybrid classification techniques and Normalized Difference Vegetation Index (NDVI) was employed to analyze bamboo forest cover changes from 1985 to 2019. Focus group discussions, questionnaire, key informant interview and observation were used to identify the drivers for bamboo forest cover change. The study findings indicate that bamboo has experienced significant spatio-temporal change over the study period (1985–2019) in the study District. In the base year (1985), bamboo covered 5.1% (5277.1 ha) of the study area. Significant decline in bamboo forest had occurred in 2001 when the bamboo forests suffered the greatest devastation and shirked to 1.6%. In 2019, the bamboo has been rehabilitated from degradation and increased significantly. However, the net change over the study periods was negative where the bamboo forests declined by 0.8% (831.14 ha). The observed changes in bamboo forest cover were driven by an interplay of multiple factors. Agricultural land expansion, wildfire, free grazing, lack of regulatory mechanisms and improper harvesting and expansion of settlement areas were the top five drivers respectively while conflict, mass flowering and tenure contributed for the change. Therefore, the bamboo forests deserve great attention, and the results from this study imply the need for the concerted efforts of stakeholders for sustainable management, utilization and conservation of the bamboo resources.
•A combination of pixel-based hybrid classification techniques and Normalized Difference Vegetation Index (NDVI) was employed.•Bamboo forest has experienced significant spatio-temporal change over the study period.•The observed changes in bamboo forest cover were driven by an interplay of multiple factors.
PDF
