Review of agricultural production systems in eastern Africa in relation to food and nutrition security and climate change

The goal of this paper is to provide a unified resource for Eritrea, Djibouti, Somaliland, Somalia, Ethiopia, Kenya, Uganda, Rwanda and Tanzania. For each country the review covers the topics of livestock production systems and agroecological zones, food and nutrition security, climate change, greenhouse gas (GHG) emissions and climate-smart agriculture (CSA) with a focus on the role of, or impact on, livestock systems. Each of these topics is broad and many excellent studies and reviews have been produced covering these topics either at the country level or for the entire East Africa region. It is the goal of this paper to provide an accessible introduction to these topics and to direct readers to the resources that exist for gathering detailed information on livestock production, food nutrition and security, climate change, GHG emissions and climate-smart livestock production in each country

Temporal and spatial variability of rainfall distribution and evapotranspiration across altitudinal gradient in the Bilate River Watershed, Southern Ethiopia

Rainfall and evapotranspiration are the two major climatic factors affecting agricultural production. This study examined the extent and nature of rainfall variability from measured data while estimation of evapotranspiration was made from recorded weather data. Analysis of rainfall variability is made by the rainfall anomaly index, coefficient of variance and precipitation concentration index. The FAO-56 reference ET (ETo) approach was used to determine the amount of evapotranspiration. Estimation of the onset, end of growing season and length of growing period was done using Instat software. The results show that mean annual rainfall of the upper (2307 m.a.s.l), middle (1772 m.a.s.l) and lower (1361 m.a.s.l) altitude zones of the watershed are in the order of 1100, 1070 and 785 mm with CV of 12, 15 and 17% respectively. There was a high temporal anomaly in rainfall between 1980 and 2013. The wettest years recorded Rainfall Anomaly Index of +5, +6 and +8 for stations in upper, middle and lower altitude zones respectively, where the driest year recorded value is -5 in all the stations. The average onset date of rainfall for the upper zone is April 3 ± 8 days, for the middle zone April 10 ± 10 days and for the lower zone is April 11 ± 11 days with CV of 23%, 26 and 29% respectively. The average end dates of the rainy season in the upper and middle zones are October 3 ± 5 days and September 25 ± 7 days with CV 5 and 7%. The main rainy season ends earlier in the lower zone; it is on July 12 ± 10 days with CV of 14%.Keywords: Variability, days of the year (DOY), onset, end date, length of growing period (LGP

Review of policies and frameworks on climate change, agriculture, food and nutrition security in Ethiopia

Agriculture is the mainstay of Ethiopia’s economy, contributing over 50% of the gross domestic product (GDP), accounting for more than 85% of the labor force and over 90% of the foreign exchange earnings (Alemu et al. 2010). Consequently, the sector receives considerable attention from the government, investing 15% of its total budget over the decade and meeting the commitments by Africa’s heads of states to the African Union Maputo 2003 Declaration on Agriculture and Food Security (CAADP 2003). On average, crop production makes up 60% of the sector’s outputs, livestock accounts for 27%, with other sub-sectors contributing 13% of the total value of agricultural production. The sector is dominated by small-scale farmers, practicing rain-fed mixed farming using traditional technologies, characterized with low levels of input use and low productivity

Environmental changes and the rise and fall of civilizations in the northern Horn of Africa: an approach combining δD analyses of land-plant derived fatty acids with multiple proxies in soil

International audienceThe domains of the ancient polities D'MT and Aksum in the Horn of Africa's highlands are a superior natural system for evaluating roles of environmental change on the rise and fall of civilizations. To compare environmental changes of the times of the two polities, we analyzed stable hydrogen isotopic ratios (δD) of land-plant derived fatty acids (n-C26-30) and other proxies from soil sequences spanning the Holocene from the region. Three results suggest that trends in δD values unambiguously reflect changes in rainfall. First, increases in δD coincide with dry periods inferred from studies of eastern African lakes. Second, changes in δD values were parallel among sections during overlapping time intervals. Third, consideration of vegetation history did not alter directions of trends in δD values over time. By unambiguously recording precipitation, the δD values also enhanced interpretations of proxies that are affected by both climate and land clearing. Both D'MT (ca 2750-2350 cal y BP) and the Aksumite (ca 2100-1250 cal y BP) rose during wetter intervals of the drier part of the Holocene (after ca 6000 cal y BP). Analyses of charred matter indicated that fire had been a common agent of land clearing in all sites. The influence of climate on fire varied, however. Prior to the emergence of D'MT, δD values were correlated with C4:C3 plant ratios estimated from δ13C values. There are no C4 trees and precipitation may have been the main influence on canopy openness. After ca 4300 cal y BP, there was no significant relationship between δD and C4:C3 plant ratios suggesting that factors such as fire influenced canopy openness regardless of climate. Furthermore, the impact of land clearance differed between sites and between D'MT and the Aksumite's times. In one site, the interval from 3550 cal y BP to the decline of D'MT had several anomalies that suggested dramatic increases in thermal severity of fire and human impact. Among these were a large contribution of charred matter to a high% total organic carbon that low hydrogen and oxygen indices suggest was severely altered by other factors than humification. These results support hypotheses about the rise of civilizations being favored by specific climatic conditions but suggest that patterns of land clearing differed during the declines of D'MT and the Aksumite

Anthropogenic forcing increases the water-use efficiency of African trees

Rising atmospheric CO2 concentrations affect climate directly through radiative effects and indirectly by changing plant water-use efficiency. Under global warming scenarios these widely reported changes will have a substantial impact on future bush encroachment, crop yields, river flow and climate feedbacks. Tree-ring intrinsic water-use efficiency (iWUE) records for Africa show a 24.6% increase over the 20th century. As high iWUE can partly counterbalance projected decreases in regional precipitation, this research has important implications for those involved in water resource management and highlights the need for climate models to take physiological forcing into account.National Geographic Society - Science and Exploration Europe (grant GEFNE80-13), the Royal Geographical Society, the Quaternary Research Association, the Palaeo-Anthropological Scientific Trust, the National Research Foundation, SysTem for Analysis, Research and Training (START) and the Climate Change Consortium of Wales.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-14172017-05-31hb2016Mammal Research Institut

Forest soils of Ethiopian highlands : their characteristics in relation to site history : studies based on stable isotopes

Isotopic composition and nutrient contents of soils in forests, pastures and cultivated lands were studied in Menagesha and Wendo-Genet, Ethiopia, in order to determine the effects of land use changes on soil organic matter, the N cycle and the supply of other nutrients. In the Menagesha forest, which according to historical accounts was planted in the year 1434-1468, 5I3C values at > 20 cm soil depth of from -23 to -17%o and in the surface layers of from -27 to -24%o suggest that C4 grasses or crops were important components of the past vegetation. At Wendo-Genet, the 5'3C values in the topsoils of from -23 to -16%o and in the > 20 cm of from -16 to -14%o indicated more recent land use changes from grassland to forest. At Menagesha, 5I5N values shifted from -8.8%o in the litter to +6.8%o in the > 20 cm. The low 5I5N in the litter (-3%o) and topsoils (0%o) suggest a closed N cycle at Menagesha. At Wendo-Genet, the high 5I5N (3.4-9.8%o) and low total N concentrations suggests a more open N cycle with greater N losses. At Menagesha, the variation in soil nutrient contents followed the patterns of %C and %N. At the mid-altitudes, where there had been undisturbed forest cover for > 500 years, %N and %C were higher and the surface layers showed high accumulation of Ca and S. The strong relation between %C and CEC, suggests that organic matter increases the nutrient retention capacity of these soils. Exchangeable and total Ca were strongly related (r2 = 0.95, P < 0.001). It is suggested that the presence of forests in this otherwise bare landscape leads to interception of base cations in dust, which can help to sustain a productive forest. The studies show that the approach to combine stable isotopes with nutrient elements is especially useful when studying the chemical properties of forest soils in relation to site history. They also show that productive forests with a high soil organic matter content can be established on fairly steep slopes in the Ethiopian highlands

Physiological, Biochemical, and Growth Parameters of Fogera Cattle Calves to Heat Stress during Different Seasons in Sub-Humid Part of Ethiopia

Fogera cattle are among indigenous breeds of cattle in the northern part of Ethiopia. However, their response to heat stress (HS) under different seasonal variations has not been well investigated. This study was aimed to determine physiological, hematological, biochemical, and growth parameters of Fogera cattle calves to HS during dry season, short rainy, and long rainy. A total of 72 calves (24 for each season) that were 6 months of age with an equal number of males and females were evaluated for physiological, hematological, biochemical, and growth parameters. Daily ambient temperature (AT) and relative humidity (RH) were recorded two times per day during the study periods from which the daily average temperature–humidity index (THI) was calculated. The study revealed higher AT and THI during dry and short seasons while higher RH was observed during the long rainy season. Physiological parameters except rectal temperature were affected by the seasons. Hematological parameters were also affected by season except for packed cell volume. Biochemical and growth parameters were also significantly affected by the seasons. THI was positively related with physiological but negatively with growth parameters. Thus, the THI value of 66 can be considered as optimum for high weight gain and normal physiological response to HS in Fogera cattle calves under their current production system

Urban church forests for local temperature regulation: Implications the role of managing and incorporating urban green space in urban planning

The global surface temperature shows an increment of 0.50.1C per decade and 1.050.3C per century from 1880-2014 with greater increases in cities than non-urban areas. Global communities are shifting towards urbanization due to various factors. Urbanization has caused lack of stable condition for dwellers due to environmental and anthropogenic factors such as land cover changes. Urban temperature rising is the main factors hindering urban dwellers at global level due to insufficient green areas. Social institutions are playing important role in urban greening and urban climate regulation. Ethiopian Orthodox Tewahido Church has long history in indigenous trees biodiversity conservation that plays largely greening role in urban and rural parts of the country. However, there is a research gap in Ethiopia regarding the role of urban green area in the church yards in regulating urban temperature and microclimate change. Therefore, the study evaluated the role of church managed forests in Addis Ababa in regulating surface temperature. Surface temperature inside four church forests at a buffer radius of 0–50 m, 50–100 m, 100–200 m and 200–500 m estimated using Landsat image thermal band 6 of 1986, 2000 and 2010 and ground measurement by ambient thermometer at 10:00 am, 12:30 am and 3:00 pm local time. The ground measurement was done in order to validate satellite image analysis. Plant species diversity, DBH, H, HC, BH and BA was measured. There were 1167 trees in the four studied churches. The mean temperatures of the studied sites were 22.50.1, 23.250.2, 240.6, 24.61.1 and 25.52.2C on site,0–50 m, 50–100 m, 100–200m and 200–500 m respectively for 1986 images; 23.20.5, 23.31.0, 24.32.1, 24.82.2 and 25.51.8C on site, 0-50 m, 50–100 m, 100–200 m and 200–500 m respectively for 2000 images and 23.20.3, 23.270.2, 23.71.6, 241.4 and 24.71.3C on site, 0–50 m, 50–100 m, 100–200 m and 200–500 m respectively for 2010 images. The result illustrated a significant influence of green area on urban temperature in the buffering radius and implies the possibility of regulating urban temperature by planning urban green area in appropriate radius intervals. The study indicated that church forests in particular, social institution and urban green area in general have significant role in urban temperature regulation

Large paleoenvironmental insights from tiny molecules that "don't do anything": lessons from French and Ethiopian deposits.

International audiencePaleoenvironmental records provide insights into fundamental questions about structural changes in past human populations. Three problems with proxies lower the resolution of such records: 1) spatio-temporal discontinuity, 2) reflecting multiple factors at once, and 3) decomposition beyond recognition. Analyses of specific lipid molecules that "don't do anything" in soils and sediments are overcoming these obstacles. These are products of decomposition that resist further chemical change. Stable hydrogen isotopic compositions (δD) of molecules with long carbon chains in fatty acids and alkanes are providing records of paleoprecipitation. The records' accuracy may be undermined by changes in cover of their plant sources. Correcting for changes in C3 and C4 plant cover did not alter δD trends from fatty acids in Ethiopian soil sections and reflected shifts in precipitation amounts. In contrast, δD values of specific alkanes in soils along an elevation transect of Ethiopian agricultural stations did not reflect precipitation trends unless differences in C3 and C4 plant cover were accounted for. Pentacyclic triterpene methyl ethers (PTMEs) include potential biomarkers for specific plant types. The PTME miliacin is specific to broomcorn millet in the French Lake Bourget area. In addition to providing precipitation inferences that are not affected by changes in plant sources, its contents in sediments provide insights into millet agriculture by Bronze Age peoples where artifacts such as seeds have decomposed. Another PTME, crusgallin, is found only in grasses and its δD values are showing greater sensitivity to changes in precipitation than fatty acids from soils near ancient Ethiopian civilizations