Timing of breeding in free-ranging Ethiopian hedgehogs,Paraechinus aethiopicus,from Qatar

There is little information pertaining to the breeding behaviour and reproductive biology of free-ranging hedgehog populations outside of Europe. We monitored the seasonal changes in courtship behaviour and the presence of new young animals from a free-ranging Ethiopian hedgehog population in Qatar between 2010 and 2012. Based on frequencies of courtship behaviour and deduced frequencies of successful mating, the mating season of the Ethiopian hedgehog is believed to start in January and continue through until July with a clear peak during the February/March period. We propose the existence of two mating peaks, one in February/March and the second in June, suggesting that free-ranging Ethiopian hedgehogs breed more than twice a year in Qatar. Successful mating in late winter/early spring may be more important for the increasing the inclusive fitness of the parents based on the number of young individuals that survive beyond one month of age.     

Forecasting the Ethiopian Coffee Price Using Kalman Filtering Algorithm

Ethiopian coffee price is highly fluctuated and has significant effect on the economy of the country. Conducting a research on forecasting coffee price has theoretical and practical importance.This study aims at forecasting the coffee price in Ethiopia. We used daily closed price data of Ethiopian coffee recorded in the period 25 June 2008 to 5 January 2017 obtained from Ethiopia commodity exchange (ECX) market to analyse coffee prices fluctuation. Here, the nature of coffee price is non-stationary and we apply the Kalman filtering algorithm on a single linear state space model to estimate and forecast an optimal value of coffee price. The performance of the algorithm for estimating and forecasting the coffee price is evaluated by using root mean square error (RMSE). Based on the linear state space model and the Kalman filtering algorithm, the root mean square error (RMSE) is 0.000016375, which is small enough, and it indicates that the algorithm performs well.     

Crustal tomographic imaging of a transitional continental rift: the Ethiopian rift

In this study we image crustal structure beneath a magmatic continental rift to understand the interplay between crustal stretching and magmatism during the late stages of continental rifting: the Main Ethiopian Rift (MER). The northern sector of this region marks the transition from continental rifting in the East African Rift to incipient seafloor spreading in the southern Red Sea and western Gulf of Aden. Our local tomographic inversion exploits 172 broad-band instruments covering an area of 250 × 350 km of the rift and adjacent plateaux. The instruments recorded a total of 2139 local earthquakes over a 16-month period. Several synthetic tests show that resolution is good between 12 and 25 km depth (below sea level), but some horizontal velocity smearing is evident along the axis of the Main Ethiopian Rift below 16 km. We present a 3-D P -wave velocity model of the mid-crust and present the first 3-D Vp / Vs model of the region. Our models show high P -wave velocities (6.5 km s⁻¹) beneath the axis of the rift at a depth of 12–25 km. The presence of high Vp / Vs ratios (1.81–1.84) at the same depth range suggest that they are cooled mafic intrusions. The high Vp / Vs values, along with other geophysical evidence, suggest that dyking is pervasive beneath the axis of the rift from the mid-crustal depths to the surface and that some portion of partial melt may exist at lower crustal depths. Although the crustal stretching factor across the Main Ethiopian Rift is ∼1.7, our results indicate that magma intrusion in narrow zones accommodates a large proportion of extensional strain, with similarities to slow-spreading mid-ocean ridge processes.     

The sensitivity of East African rift lakes to climate fluctuations

Sequences of paleo-shorelines and the deposits of rift lakes are used to reconstruct past climate changes in East Africa. These recorders of hydrological changes in the Rift Valley indicate extreme lake-level variations on the order of tens to hundreds of meters during the last 20,000 years. Lake-balance and climate modeling results, on the other hand, suggest relatively moderate changes in the precipitation-evaporation balance during that time interval. What could cause such a disparity? We investigated the physical characteristics and hydrology of lake basins to resolve this difference. Nine closed-basin lakes, Ziway-Shalla, Awassa, Turkana, Suguta, Baringo-Bogoria, Nakuru-Elmenteita, Naivasha, Magadi-Natron, Manyara, and open-basin Lake Victoria in the eastern branch of the East African Rift System (EARS) were used for this study. We created a classification scheme of lake response to climate based on empirical measures of topography (hypsometric integral) and climate (aridity index). With reference to early Holocene lake levels, we found that lakes in the crest of the Ethiopian and Kenyan domes were most sensitive to recording regional climatic shifts. Their hypsometric values fall between 0.23–0.29, in a graben-shaped basin, and their aridity index is above unity (humid). Of the ten lakes, three lakes in the EARS are sensitive lakes: Naivasha (HI = 0.23, AI = 1.20) in the Kenya Rift, Awassa (HI = 0.23, AI = 1.03) and Ziway-Shalla (HI = 0.23, AI = 1.33) in the Main Ethiopian Rift (Main Ethiopian Rift). Two lakes have the graben shape, but lower aridity indices, and thus Lakes Suguta (HI = 0.29, AI = 0.43) and Nakuru-Elmenteita (HI = 0.30, AI = 0.85) are most sensitive to local climate changes. Though relatively shallow and slightly alkaline today, they fluctuated by four to ten times the modern water depth during the last 20,000 years. Five of the study lakes are pan-shaped and experienced lower magnitudes of lake level change during the same time period. Understanding the sensitivity of these lakes is critical in establishing the timing or synchronicity of regional-scale events or trends and predicting future hydrological variations in the wake of global climate changes.     

IDENTITY AND ASSIMILATION AMONG YOUNG ETHIOPIAN IMMIGRANTS IN METROPOLITAN WASHINGTON*

ABSTRACT. Ethiopians are a recent immigrant group in the United States, having entered the country in significant numbers during the 1980s and 1990s. This preliminary study examines the ethnic and racial identities of children of first‐generation Ethiopian immigrants living in the Washington, D.C. metropolitan area. The results of twenty in‐depth interviews demonstrate that race is a much more fluid and contested form of identification than is ethnicity to the young immigrants, who equate the latter unilaterally with their Ethiopian heritage. Immigrants also adopt different subject identities in various locales, favoring those that are most in accordance with their needs and sense of self.     

Human and Environmental Factors Affect Patterns of Crop Diversity in an Ethiopian Highland Agroecosystem

The Ethiopian highlands are a center of diversity for numerous globally important crops. Heterogeneous landscapes, traditional agricultural practices, and inaccessibility have created and maintained diverse subsistence agroecosystems. We surveyed sixty-three farms in twelve communities of the Gamo highlands and found high levels of on-farm diversity of crop species and varieties. The extent and nature of this diversity are related to both ecological factors, namely elevation, and anthropogenic factors such as land-use history, accessibility to markets and extension, and strength and scale of farmer exchange networks. These human landscape features have the potential to both enhance and mediate effects of elevation and other environmental factors on crop diversity. The interaction of environmental and anthropogenic forces on the diversity of crops grown by farmers affects the strategies farmers employ to adapt their farming to changing conditions.     

Changes in soil nutrients, vegetation structure and herbaceous biomass in response to grazing in a semi-arid savanna of Ethiopia

The effect of grazing was studied on vegetation structure, herbaceous biomass, basal and bare ground covers, together with soil nutrient concentrations in two locations in an Ethiopian semi-arid savanna. The lightly grazed sites had significantly higher herbaceous diversity, total abundance, basal cover and aboveground biomass, and a lower percentage of bare ground compared with the heavy grazed sites. Grazing pressure had no effect on the density and number of woody species as well as on the proportion of encroaching woody species. The light grazing sites had higher organic carbon, phosphorus and exchangeable bases, and therefore a higher pH and higher electrical conductance, indicating an improved soil nutrient status compared with heavy grazing sites, mainly attributed to the higher basal cover and standing biomass at light grazed sites, and the export of nutrients through grazing and dung collection from the heavily grazed sites. There were significantly higher soil nutrients, species diversity, aboveground biomass and basal cover in the light grazing sites compared with heavy grazing sites. We concluded that changes in herbaceous vegetation, standing biomass and soil compositions are caused by interactions between grazing, soil and vegetation, and these interactions determine the transitions of semi-arid savannas.     

Non-climatic growth of the saline Lake Beseka,Main Ethiopian Rift

When using rift lakes as proxies for palaeoclimate it is essential to know if water level changes are of geological or climatic origin, and whether a reinterpretation of palaeo-lake levels derived from lithostratigraphic sequences is required. The saline, endorheic Lake Beseka is located in the tectonically active Main Ethiopian Rift. Despite the aridity of the rift valley the lake's surface area quadrupled from 11.1 km² in 1973 to 39.5 km² in 2002. We quantify the lake growth by means of a detailed bathymetric model and high-resolution satellite time series. We analyse the potential climatic, anthropogenic, and tectonic agents of Lake Beseka's growth. Multitemporal remote sensing data and meteorological records were compared with in-situ measurements of hydrochemical parameters and water depth to address the reason for the lake level rise. Our results suggest that Lake Beseka's expansion originates from an increased discharge of the hot springs. The combined analysis of satellite data and in-situ measurements proved to be a valid tool for the quantification of lake level changes and can help to detect the causes of these variations.     

The Role of Coffee in the Development of Southwest Ethiopia's Forests: Farmers' Strategies,Investor Speculation,and Certification Projects

This article examines the role of coffee in the agriculture of southwest Ethiopian highlands, a context characterized by recent huge private coffee estate developments, coffee certification projects and smallholdings. The analysis shows that smallholder farmers prioritize staple crops, and allocate land and labor to coffee only once food production objectives have been reached. It also underscores the diversity of the local peasantry, often treated as a homogeneous group in development projects designed to boost farmers' income through coffee production. Based on this analysis, the article evaluates the effects of recent coffee-oriented development policies: state forest concessions for coffee investment, and two coffee certification projects (UTZ-Certified and Fair-Trade/Organic). Because they omit the differentiated farmers' strategies, these certification initiatives fail to improve local populations' livelihoods and accelerate incipient socioeconomic inequalities. Moreover, when applied to big private plantations, they participate in farmers' dispossession from critical forest resources essential to households' food self-sufficiency.     

Diatom-derived palaeoconductivity estimates for Lake Awassa, Ethiopia: evidence for pulsed inflows of saline groundwater

A 6,500-year diatom stratigraphy has been used to infer hydrochemical changes in Lake Awassa, a topographically closed oligosaline lake in the Ethiopian Rift Valley. Conductivity was high from ~6400-6200 BP, and from 5200-4000 BP, with two brief episodes of lower conductivity during the latter period. Although the timing of the conductivity changes is similar to the timing of lake-level change in the nearby Zwai-Shalla basin, their directions are the reverse of that expected from a climatic cause. Dissolution of the tephras which precede both phases of high conductivity cannot explain the increases in salinity, because rhyolitic tephras are only sparingly soluble. Instead, the pulsed input of groundwater made saline by the reaction of silicate minerals and volcanic glass with carbonic acid, formed from the solution of carbon dioxide degassed from magma under the Awassa Caldera, is suggested as a plausible mechanism for the observed change in lake chemistry. Diatom-inferred hydrochemistry cannot therefore be used to reconstruct climate change in Lake Awassa.     

Relocation of M ≥ 2 events of the 1989 Dôbi seismic sequence in Afar: evidence for earthquake migration

The Ethiopian side of central Afar was struck in August 1989 by the largest seismic sequence (three 6.1 ≤ M _s ≤ 6.3 events, 15 with M _s or m _b ≥ 5.0) since that of Serdo in 1969. Using the Djibouti seismological network, we relocated 297 of the events of that sequence. As most of the large events took place outside the network, we assessed the accuracy and stability of earthquake relocations by using three different velocity models and two relocation codes to try to relate individual shocks to distinct faults and surface breaks. A majority of the events apparently occurred underneath the floor of the Dôbi graben, an area about 45  km long and 15  km wide, rupturing boundary and inner floor faults, in agreement with the surface cracks and scarps that we mapped in the area. The relocation shows that the principal events propagated about 50  km northwestwards along the graben in the first 40  hr. A day and a half after the beginning of the sequence, smaller events ( M ≤ 4) started to propagate more than 55  km eastwards, towards Asal Lake. Using two three-component stations installed near the Ethiopian border, we could determine reliable depths for 21 events. The depths are compatible with a seismogenic crust about 14  km thick in the Dôbi and Hanle graben area. Although the Dôbi sequence ruptured about 50  km of the fault array extending from Serdo to Asal, where the regional stress was released by earthquakes in 1969 and 1978, respectively, a seismic gap about 50  km long still subsists along the northern part of the Gaggade region (Der'êla half-graben).     

Palaeointensity results from Ethiopian basalts: implications for the Oligocene geomagnetic field strength

From a large collection of Ethiopian flood basalts (~30  Myr old) sampled for magnetostratigraphy, ⁴⁰Ar/³⁹Ar geochronology and geochemical investigations, 47 samples were selected in order to test their suitability for Thellier palaeointensity experiments. Only 17 samples from eight individual flows yielded reliable palaeointensity estimates, with flow-mean virtual dipole moments ranging from 3.0 to 10.5 × 10²²  A  m² .
  A critical review of the Oligocene palaeointensity data set, including these new Ethiopian data, indicates an Oligocene mean virtual dipole moment of 5.1 ± 2.5 × 10²²  A  m² for the complete data set. After applying mild selection criteria, the reduced data set yields a mean value of only 4.6 ± 1.9 × 10²²  A  m² . This value is significantly lower than the present-day field strength but is higher than the Mesozoic dipole low mean field. This low Oligocene field might be in agreement with the high palaeosecular variation and rather high non-dipole field invoked around 30  Ma. However, the Oligocene data set is largely dependent on the palaeointensity determinations from Armenia, obtained mainly from baked contacts, which show amazingly low dispersion at both flow and between-flow levels. More data are needed to reduce the weight of these determinations on the mean value and avoid a possible bias.     

Dynamics and driving factors of late Holocene gullying in the Main Ethiopian Rift (MER)

The issue of determining the driving factors in gullying, apart from land use, is somewhat lagging in comparison with the study of their physical modelling and control technology. Available information focuses on the basic ideas of climatic control, anthropic determinism and internal “authigenic” dynamics. High resolution chronology of cyclic systems, common in extensively gullied areas, can provide a clue to the weight of each factor. This paper reports a study of this kind, focusing on two gully catchments in the Main Ethiopian Rift (MER), but backed by an extensive regional survey. By integrating tracing and correlation of unconformity-bounded stratigraphic units and soils with radiocarbon dating, a detailed chronology was obtained for the last 5000 years. This could be compared with proxy climate reconstructions of similar detail. Clear evidence of climatic control emerged; gully filling is triggered by decreased stream transport capacity and increased sediment supply during transitions towards drier climate phases, while gully entrenchment appears to take place at the start of moist intervals, for the reverse reasons. A broader consideration of geological setting, however, puts forward a more general interpretation. These gullies actually formed, in the beginning, as part of the land surface response to sudden, very recent tectonic events, which created accommodation space for temporary sediment stores. They should then be seen in the frame of the Discontinuous Ephemeral Stream (DES) concept; as such, they are intrinsically non-linear and complex phenomena, whose response is linearized by a strong climatic–vegetational forcing, acting on both channel flow and sediment supply.     

Spatiotemporal wetland changes and their threats in North Central Ethiopian Highlands

Wetlands are important environmental resources for rural livelihoods in Ethiopia. The study investigated spatiotemporal change of wetlands, drivers and effects in North Central Ethiopian Highlands. Landsat satellite imageries of 1984, 1993, 2000, and 2013 were used to analyse wetland changes over the last three decades. Practical observations, interviews and discussions with local communities and officers were also conducted to address the main objective. Furthermore, secondary data on crop yields were collected to supplement the primary data. The study shows that wetlands have been converted into built‐up areas and farmlands. Wetlands in the study area experienced annual loss across the entire study period. Consequently, the area size of wetlands decreased from 7.4 per cent in 1984 to 2.6 per cent in 2013. About 66 per cent of the total wetlands was lost within 30 years mainly due to farmland encroachment and urban expansions. The highest rate of wetland change was recorded between 2000 and 2013. Such wetland changes increased conflicts among land users. However, the converted wetlands increased short‐term benefits due to wetland recession agriculture. To conclude, wetland resources are under enormous threats, and challenge the sustainability of livelihoods. Thus, integrated and adaptive wetland restoration policies could improve the degraded wetlands.     

Palaeoclimatic implications of isotopic data from modern and early Holocene shells of the freshwater snail Melanoides tuberculata, from lakes in the Ethiopian Rift Valley

Carbon and oxygen isotope ratios in the shells of the freshwater snail Melanoides tuberculata yield information on the isotopic composition of the water in which the shell was formed, which in turn relates to climatic conditions prevailing during the snails' life span. Melanoides is particularly important because it is widespread in Quaternary deposits throughout Africa and Asia and is ubiquitous in both fresh and highly evaporated lakes. Whole-shell and incremental growth data were collected from modern and fossil shells from two lakes in the Ethiopian Rift Valley. 18O values in the modern shells from Lake Awassa are in equilibrium with modern waters, while 18O values in subfossil shells from the margins of Lake Tilo indicate high rainfall during the early Holocene. Sequential analysis along the growth spiral of the shell provides information on seasonal or shorter-term variability of lake water during the lifetime of the organism.     

Ecological succession and land use changes in a lake retreat area (Main Ethiopian Rift Valley)

In the semi-arid Main Ethiopian Rift Valley, ecological succession is related to continuous lake retreat. Human activity, through its impact on land use and cover, affects this ecological succession at various degrees. Through a remote sensing study, we explored how the drivers for land use and cover changes (LUCC) have changed over the last decades and which impact this has on ecological succession. Remote sensing data used include a Landsat MSS from 1973, a Landsat TM from 1986 and Landsat ETM+ from 2000; a conventional type of classification was used whereby supervised classification of the 2000 image was supplemented by unsupervised classification of the older images. Due to decreased rainfall and water abstraction for intense irrigated agriculture in its catchment, Lake Abijata lost 46% of its area between 2000 and 2006. On the emerged land, an ecological succession was observed along the environmental gradient of the retreating lake: emerged bare land, grassland, land with few scattered Acacia shrubs and open woodlands. Between 1986 and 2000, LUCC tendencies were totally reversed and woody vegetation decreased strongly, indicating increased human impact. This land degradation took place in a context of instable political situation, fuelwood extraction, higher population density and better communications.     

An automated method for mapping physical soil and water conservation structures on cultivated land using GIS and remote sensing techniques

An efficient and reliable automated model that can map physical Soil and Water Conservation (SWC) structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and ArcGIS®, ERDAS IMAGINE®, and SDC Morphology Toolbox for MATLAB and statistical techniques. The model was developed using the following procedures: (1) a high-pass spatial filter algorithm was applied to detect linear features, (2) morphological processing was used to remove unwanted linear features, (3) the raster format was vectorized, (4) the vectorized linear features were split per hectare (ha) and each line was then classified according to its compass direction, and (5) the sum of all vector lengths per class of direction per ha was calculated. Finally, the direction class with the greatest length was selected from each ha to predict the physical SWC structures. The model was calibrated and validated on the Ethiopian Highlands. The model correctly mapped 80% of the existing structures. The developed model was then tested at different sites with different topography. The results show that the developed model is feasible for automated mapping of physical SWC structures. Therefore, the model is useful for predicting and mapping physical SWC structures areas across diverse areas.     

Are ferns in arid environments underestimated? Contribution from the Saharan Mountains

Although ferns are able to colonize dry regions through specific adaptations, they are suggested to be rare in arid environments. By comparing recent observations in the South-Saharan Mountains with existing data from the whole Sahara, we re-evaluated the distribution of the understudied Saharan fern diversity. Observations in the Aïr Mountains (Niger) from 2003 to 2006 identified six ferns species, among which three were new records for the Aïr and for Niger. A total of 17 species are currently known from the Sahara. The desiccation tolerant Actiniopteris radiata and Cheilanthes coriacea were located in habitats with abiotic refuges providing shade, whereas the drought avoiding Ophioglossum polyphyllum was found in a sandy highland plain. All were growing in isolated populations at elevations above 1600 m. These results, combined with data from the Hoggar and the Tibesti mountains, indicate that ferns are more frequent than initially thought in arid environments thanks to efficient dispersal, elevation refuges, physiological adaptations, and the presence of local abiotic refuges. The three newly recorded species most likely radiated from the Ethiopian highlands. Their deep isolation, their rarity, and their successful adaptation to drought suggest that their conservation status might be particularly high.     

RAINFALL CHANGE AND ITS IMPLICATIONS FOR BELG HARVEST IN SOUTH WOLLO, ETHIOPIA

Most farmers in the Ethiopian highlands depend on rain‐fed agriculture. Some areas have the favourable situation of having two rainy seasons, Belg (February‐May) and the long rainy season Kiremt (June‐October), which is the case in some parts of South Wollo. Tef (Eragrostis tef) is the staple crop that farmers prefer to grow and the 90‐day variety is suitable for growing during the short rainy season. One out of eight Ethiopians lives in tef potential areas which have Belg rainfall. The aim in this study is to analyse rainfall variation in South Wollo, in particular the area east of the small town of Hayk, and to study its effect on the ability to grow tef during the Belg season. Results from interviews showed that a more difficult farming situation had emerged during the past 40 years, largely due to deterioration of physical resources such as rainfall. Rainfall is analysed by comparing daily rainfall data from four stations in two periods, 1963 to 1982 and 1984 to 2003, for changes in totals, seasonal distribution and variability. Coefficient of variance, rainy days, rainfall intensity and dry spells were analysed. Results from this study show that there have been minor rainfall changes but greater rainfall variability. During fieldwork key informants were asked if they were able to harvest tef during the past nine years, a period that has been used in a model of rainfall influence on tef cultivation during the Belg season. In both 20–year periods, farmers were able to grow tef every second year. In spite of a greater variability in rainfall the farmers proved their knowledge and flexibility and were able to harvest tef in the same number of years during both periods.     

Wood biomass functions for Acacia abyssinica trees and shrubs and implications for provision of ecosystem services in a community managed exclosure in Tigray,Ethiopia

In the Ethiopian highlands, remarkable recovery of vegetation has been achieved using exclosures, protecting vegetation against livestock browsing and firewood harvesting. But these emerging forest resources require tools for sustainable use, implying knowledge on biomass stocks and growth. In this study we developed biomass functions estimating total, stem and branch biomass from diameter at stump height (DSH) and tree height (H) for an 11-year old exclosure in Tigray, Ethiopia. In a systematic grid of 55 plots, DSH and H of all trees and shrubs were recorded. 40 Acacia abyssinica trees were selected for destructive sampling. Allometric relationships using a natural log–log model were established between aboveground biomass, DSH and H. Models with only DSH were found best with R² between 0.95 and 0.98. The functions were 10 fold cross-validated and R²_{_}cv ranged from 0.94 to 0.97, indicating good model performance. The models were found well in range with those of other seasonal forests in East Africa. Total aboveground biomass was estimated 25.4 ton ha⁻¹ with an annual production of 2.3 ton ha⁻¹, allowing sustainable wood fuel use for 4 persons ha⁻¹. The presented predictive functions help to harmonize between ecological and societal objectives and are as such a first step towards an integrated planning tool for exclosures.