Time Budget on Major Activities of Livestock Grazing Heterogeneous Natural Range and Crop Fields in Semi-Arid Nigeria

Semi-arid rangelands of West Africa provide herbs, trees and shrubs, which together with crop residues form the main sources of feed for the livestock population. Feed supply in this region is characterised by a progressive decline in quantity and quality with advancing dry season. It was reported that walking ability as well as watering frequencies affect the productivity of grazing livestock (Dicko and Sangare, 1984). This study tests the hypothesis that advancing season increases both time spent walking as well as feeding, with a switch from grazing to browsing

Implications of Land Use Changes on the Yields in Dry Matter, Energy and Protein of Range and Crop Fields in Zamfara Reserve, Northwestern Nigeria

The Zamfara reserve is a 235,500 ha grazing land within the Sudan savannah zone (12º 10\u27 - 13º 05 N; 6º 30\u27 - 7º15\u27 E) of north western Nigeria. Rainfall varies from 500mm in the north to 800mm in the south of the reserve, and is restricted within the months of May - September. The reserve is an important grazing site for the herds of sedentary, transhumant and agro pastoralists. Population growth within the farming communities in the reserve has led to the conversion of more grazing land to croplands. This work was carried out to evaluate the quantity and quality of herbage on the natural range and the croplands, in order to have an insight on the effect of increased cropping activity on biomass availability in the reserve

Implications of restricted access to grazing by cattle in wet season in the Sahel

To address the problem of restricted access to grazing by cattle in wet season in the Sahel, a grazing trial was conducted to study the effect of duration of grazing and grazing method on cattle nutrition and performance. Twenty-four intact steers weighing 259 kg (SD ¼ 62) were randomly allotted to four treatments to study the effect of the combination of grazing method (tethering and close herding) and grazing duration (6 and 9 h per day) on diet selection, faecal output, forage intake, grazing behaviour and weight changes in the wet season. Three esophageally fistulated steers were used in a cross-over design to sample diet selected by tethered and herded animals. Extrusa samples from esophageally fistulated steers and faecal output from intact steers were collected in weeks 6 and 9 of the experiment and grazing behaviour of the intact steers was observed in week 6. Tethered animals selected diets of lower organic matter digestibility (OMD) but tethering had no significant effect on crude protein. Close herded steers consistently consumed more forage than those tethered in both periods. Both grazing method and duration had significant effect on ingestion rate by the steers. Tethered steers had lower average daily gain than those herded. The results demonstrate that the common practice of tethering sedentary cattle in the wet season in the southern Sahel in West Africa reduces forage intake and consequently average daily gai

Herders’ perceptions on ruminant livestock breeds and breeding management in Southwestern Niger

This study documents indigenous knowledge of breeds of cattle, sheep and goats in southwestern Niger, and includes both pastoralists and agropastoralists. Our study included sheep and goats in view of the increasing importance of small ruminants in livestock production systems in the Sahel since the drought of the 1970s and 1980s. This study was carried out under the Desert Margins Program (DMP) project on arresting land degradation and the conservation of biodiversity in desert margins of sub-Saharan Africa, partly funded by the Global Environment Facility (GEF

Foliar trait contrasts between African forest and savanna trees: Genetic versus environmental effects

Journal ArticleVariations in leaf mass per unit area (Ma) and foliar concentrations of N, P, C, K, Mg and Ca were determined for 365 trees growing in 23 plots along a West African precipitation gradient ranging from 0.29 to 1.62m a-1. Contrary to previous studies, no marked increase in Ma with declining precipitation was observed, but savanna tree foliar [N] tended to be higher at the drier sites (mass basis). Generally, Ma was slightly higher and [N] slightly lower for forest vs savanna trees with most of this difference attributable to differences in soil chemistry. No systematic variations in [P], [Mg] and [Ca] with precipitation or between trees of forest vs savanna stands were observed. We did, however, find a marked increase in foliar [K] of savanna trees as precipitation declined, with savanna trees also having a significantly lower [K] than those of nearby forest. These differences were not related to differences in soil nutrient status and were accompanied by systematic changes in [C] of opposite sign. We suggest an important but as yet unidentified role for K in the adaption of savanna species to periods of limited water availability; with foliar [K] being also an important factor differentiating tree species adapted to forest vs savanna soils within the 'zone of transition' of Western Africa.Natural Environment Research Council TROBIT Consortium projectRoyal Society - University Research Fellowshi

The economic and ecological effects of water management choices in the upper Niger river: Development of decision support methods

One million people in the Inner Niger Delta make a living from arable farming, fisheries and livestock. Upstream dams (one built for electricity generation and one for irrigation) affect this downstream multifunctional use of water. Additionally, the Inner Niger Delta, which is one of the largest Ramsar sites in the world, is a hotspot of biodiversity and accommodates two of the largest known breeding colonies of large wading birds in Africa and in addition, is a vital part of the eco-regional network, supporting up to 3 to 4 million staging waterbirds, residents and migrants from all over Europe and western Asia. The hydrological and related ecological conditions in the Inner Delta largely determine the population size of these waterbird species. The major aim of the three-year study was to develop a decision-support system for river management in the Upper Niger, in which ecological and socio-economical impacts and benefits of dams and irrigation systems can be analysed in relation to different water management scenarios. The study involves various components: hydrology, arable farming, livestock, fisheries, ecology and socio-economics. An economic analysis has been conducted to determine the role of dams in the economy of the Inner Niger Delta and the Upper Niger region. By innovatively combining the above information on hydrology, ecology, fisheries, and agriculture, the study shows that building new dams is not an efficient way to increase economic growth and reduce poverty in the region. In fact, such efforts are counter-effective. Instead, development efforts should be aimed at improving the efficiency of the existing infrastructure, as well as of current economic activities in the Inner Niger Delta itself. This approach will also provide greater certainty for the essential eco-regional network functioning of the Inner Delta. © 2006 Taylor & Francis

Structural, physiognomic and above-ground biomass variation in savanna-forest transition zones on three continents - How different are co-occurring savanna and forest formations?

Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity) in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna-forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna-forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three continents coexistence was found to be confined to a well-defined edaphic-climate envelope with soil and climate the key determinants of the relative location of forest and savanna stands. Moreover, when considered in conjunction with the appropriate water availability metrics, it emerges that soil exchangeable cations exert considerable control on woody canopy-cover extent as measured in our pan-continental (forest + savanna) data set. Taken together these observations do not lend support to the notion of alternate stable states mediated through fire feedbacks as the prime force shaping the distribution of the two dominant vegetation types of the tropical lands