Integration of transhumant pastoralism and irrigated agriculture in semi-arid East Africa

Agricultural development projects in the fertile and most well-watered areas of arid and semiarid Africa usually deny access to nomadic pastoralists whose production system and livelihood depend upon such areas in the dry season and during frequent droughts. The result can be degradation of range resources through overgrazing, and greater vulnerability of pastoralists. Recent calls for compatible land use schemes or nonexclusionary agricultural development projects in the context of pastoralist transhumance, suggest allowing pastoralists structured access to project sites in the dry season in order to utilize forage and water supplies. This paper examines the capacity of an irrigation scheme to support the seasonal influx of transhumant livestock in dry seasons of varying severity. The livestock carrying capacity of the existing mosaic of land use patterns and practices is used in the determination of the proportional areas of land use needed to absorb large seasonal concentrations of livestock.     

Modeling rendille household herd composition

Previous analysis of Rendille household herd composition revealed a transition from camel to cattle ownership for sedentary impoverished Rendille pastoralists of northern Kenya. In an attempt to delineate determinants of livestock holdings, logistic regression analysis of 112 household herds from the Rendille settlement of Korr, Marsabit District, Kenya was undertaken. Results indicated that household wealth, measured in present livestock holdings, past drought losses, and livestock sales, formed better predictors of cattle ownership than did household characteristics pertaining to labor supply, wage earners, age-set membership, and birth order of household head. These results are discussed in light of pastoral strategies designed to minimize risk.     

Uplift of the roof of africa and its bearing on the evolution of mankind

Evidence concerning the geomorphological evolution of the Western Rift Valley, sedimentation within the valley and comparison of the fossil mammalian faunas of Western Uganda and East Africa indicate that the mountain ranges which now flank the Western Rift were uplifted in three or more stages beginning during the upper Miocene and that they reached climatically important altitudes during the upper Pliocene, at which time they began to modify regional climatic patterns in East Africa. Their main effect was the xerification of conditions over much of the region east of the mountains. The regional climatic effects due to the mountain ranges were themselves modified by global climatic changes related to the onset of the Glacial Period, the two phenomena combining to yield the Present day climatic regime of East Africa. As the climate changed, so did the flora and fauna. Faunal response was of three main kinds: a) dispersal into East Africa of pre-existing forms already adapted to more xeric conditions (many bovids, some cercopithecids), b) autochthonous evolution of forms adapted to mesic environments into forms adapted to more xeric conditions (suids, elephantids, some bovids, hominids), c) displacement of species ranges of those lineages unable to adapt to changing conditions (i.e. local extinctions) (Anancus, Brachypotherium). Autochthonous evolvers, including hominids, adopted two main strategies reflected in their hard anatomy: a) dietary shift (suids, proboscideans, bovids and later Pliocene hominids) and b) locomotor changes (early Pliocene hominids).     

Wealth and pastoral dairy production: A case study from Maasailand

Much of pastoral development in Africa has been predicted on the assumed desirability of converting pastoralists to commercial beef producers. Such development has ignored two fundamental aspects of pastoral production: first, the greater human support capacity of a dual milk/meat production system, and second, significant wealth inequality within pastoral communities. This paper presents a case study based on several years of field research in Kenya Maasailand; it examines variations by wealth status in milking strategies and the level of milk offtake for human consumption. Rich households have five times the number of cattle per reference adult as poor households, but similar levels of milk consumption, due to differences in the allocation of milk between calves and people. Residential location and watering frequency also vary by wealth status, contributing to a difference in total milk production per cow.The research and the major part of the writing of this paper were done while the author was a scientist with the Kenya Country Program of the International Livestock Center for Africa. Finishing touches were done at the International Laboratory for Research on Animal Disseases. Neither organization bears responsibility for the content. I wish to thank P. N. deLeeuw for long and valuable discussions; the animal science aspects of the research also benefitted from discussions with K. Wagenaar and M. Nicholson. P. Lembuya was, as always, a faithful and demanding assistant. The useful comments of S. Sandford, T. Conelly, U. Herren, and J. Ensminger are also appreciated.     

Phenetic,biogeographical, and evolutionary study ofOrnithogalum subg.Heliocharmos (Hyacinthaceae) in the western Mediterranean basin

A macromorphological study is made on taxa of the genusOrnithogalum subg.Heliocharmos in North Africa, Spain, and France. The results obtained are consistent with data from cytogenetics, reproductive biology and strategies of reproduction. They allow the retention of two species:O. algeriense andO. umbellatum. A biogeographical and phylogenetic interpretation of the subgenus is proposed for the western Mediterranean. Theoretical views on phenetics are discussed.     

Biological control of Pythium damping‐off by seed‐treatment with pseudomonas putida: Relationship with ethanol production by pea and soybean seeds

The relationship between biocontrol activity of Pseudomonas putida strain N1R against Pythium ultimum on pea and soybean seeds and the reduction in ethanol evolution by imbibed seeds was investigated under different treatment conditions, including temperature and numbers of seed‐applied cells of the bacterium. Treatment with strain N1R increased emergence at all temperatures, except for soybean at 12 °C and reduced ethanol concentration in the spermosphere of imbibed seeds at several temperatures. The concentration of bacterial cells in the seed treatment suspension also significantly affected biocontrol efficiency and reduced ethanol production, especially in pea seeds. In contrast, the duration (0–7 h) of submergence of seeds in bacterial suspension had little effect on biocontrol activity of N1R, although submergence of soybean seeds reduced their emergence even in the absence of the pathogen or biocontrol agent. Competition for seed‐derived compounds, including ethanol, is suggested to be one possible mechanism of biocontrol of Pythium by strain N1R, which is not known to produce antifungal antibiotics.