Browsing by Author "Maryah, U.M."

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    Climate Change Impact on Plant Species Composition in Six Semi-Arid Rangelands of Northeastern Nigeria
    (Department of Geography, Nasarawa State University Keffi, 2007-12-01) Ayuba, H.K.; Maryah, U.M.; Gwary, D.M.
    In spite of the considerable advances made in understanding and modeling climate change at the international level, awareness of, and concern for, the problem in Nigeria remain poor. There is yet a considerable dearth of regional studies on the likely impact of climate change on the nation's ecosystems.This paper examines climate change impact on six semi-arid rangelands in north-eastern Nigeria. The results revealed declining forage species composition, increased bare surfaces, and increased shrub encroachment, which are indicative of the combined effects of grazing, fire, drought, desertification and climatic variability, and which call for urgent management strategies that would improve the productivity of the semi-arid rangelands thereby guarantee food security for the region as well as the country at large.
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    DESERTIFICATION AND SUSTAINABLE UTILISATION OF NATURAL FOREST RESOURCES IN BORNO STATE
    (Department of Geography, Nasarawa State University Keffi, 2002-03-12) Ayuba, H.K.; Daura, M.M.; Ijere, J.A.; Maryah, U.M.; Msheliza, Deborah S.
    The United Nations Convention to Combat Desertification (UNCCD) defines desertification as:"land degradation in arid, semi-arid, and dry subhumid areas resulting from various factors, including climatic variations and human activities (United Nations, 1994). Furthermore, UNCCD defines land degradation as a: "reduction or loss, in arid, semi-arid, and dry subhumid areas, of the biological or economic productivity and complexity of rain fed cropland, irrigated cropland, or range, pasture, forest and woodlands resulting from land uses or from a process or combination of processes, arising from human activities and habitation patterns, such as soil erosion, deterioration of the physical, chemical, and biological or economic properties of soil; and long-term loss of natural vegetation" (United Nations,1994). Desertification, if not controlled, could convert an erstwhile fertile and productive land into an infertile and unproductive one, with devastating socio-economic and political consequences for both the local and international communities.
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    DESERTIFICATION AND THE DEPLETION OF VEGETAL RESOURCES IN BORNO STATE
    (Department of Geography, Nasarawa State University Keffi, 2001-07-05) Ayuba, H.K.; Maryah, U.M.; Ijere, J.A.
    This research examines the problem of desertification and the depletion of natural vegetation in Borno Slate. Specifically, if seeks to evaluate the rote oj stakeholders in the depletion of biological resources and the implications for the Borno environment. The stratification of (he state into three ago-climatic zones (northen.?, central, and southern) enabled the researchers to ascertain the extent.of exploitation of vegetable resources in each zone. A total of450 (150for each zone) structured interviews were administered to farmers, pastoral is ts and rural women who were selected randomly within the farming areas. Field observations also constituted a major part of the field work. The results revealed that intensive exploitation of the Savanna woodland over the years to meet the ever Increasing demand of man and livestock has resulted in a desert-like landscape in this semi-arid region. The effects of this menace are many and varied. The most important being the dwindling productivity of food crops, low quality supplement of leaves, fruits and seed * pods from such frees and shrubs, hi view of this, the researchers recommend the use of improved wood stoves as a way to save the scarce wood supplies, a combination of extensive afforestation and agro forestry schemes and improvement in the management of existing indigenous woodlands rather than ’ the widely planted exotic tree species
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    HERBACEOUS SPECIES COMPOSITION AND ABOVEGROUND BIOMASS PRODUCTION IN SOME SEMI-ARID RANGELANDS, NORTHEAST, NIGERIA
    (Department of Geography, Nasarawa State University Keffi, 2000-04-01) Ayuba, H.K.; Maryah, U.M.; Nyanganji, J.K.
    Semi-arid ecosystems are known for (heir variations in the proportion of woody and herbaceous material as well as (he marked shifls in species composition and primary production that occur in response lo heavy grazing (NFST, 1993; Oksancn el al, 1995). Within a given community, some plant species arc avoided by herbivores while others arc selected as forage. The response of forage species will vary according (o (he plant's ability (o regrow alter damage, the effects of plant competition, (he abiotic conditions and (he type and intensity of grazing (Crawley. 1983: Bclsky, 1987. John and Turkington, 1995). Although many plant species are not resilient to grazing, there are reports of plants responding to grazing with increased growth and ,vigor compared with (hat of unglazed plants (McNaughlon. 1976; 1979; Paige and Whitman, 1987). However as grazing intensity increases, losses of biomass will reach levels that cannot be maintained by rcgrowlh and so the productivity will decline
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    RAINFALL VARIATION AND TUB IMPLICATIONS FOR SDII-SURFACL HYDROLOGY IN THE MANGA GRASSLANDS, NORTH EASTERN NIGLRIA.
    (Department of Geography, Nasarawa State University Keffi, 2001-07-05) Ayuba, H.K.; Ogenyi, E.C.; Maryah, U.M.
    This study investigates the relationship between sub-surface water levels and rainfall patterns in the semi-arid zone of northern Nigeria using a groundwater flaw model (Modflow for Windows). ' ' Results show that wet years in terms of high annual rainfall, are ■ accompanied by rising heads, high rate of evaporation from, and subsequent concentration of salt within the lake environment. Drought years however show falling beads, reduced salt accumulation, and in extreme cases, significant outflow of saline water from the system This (rend has serious implications on the various water-dependent socio-economic activities of (he area and on an effective management of the ground wafer resource
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    RAINFALL, PRIMARY PRODUCTION AND THE PROBLEM OF CARRYING CAPACITY IN THE SEMI-ARID ZONE OF NIGERIA,
    (Department of Geography, Nasarawa State University Keffi, 1999-07-01) Ayuba, H.K.; Maryah, U.M.; Bdliya, B.S.
    Interannual variability of rainfall and its effects on forage and livestock productivity on the rangelands of the arid zone of North East (N.E.) Nigeria poses basic questions regarding the sustainability of the system under variable rainfall regimes, and creates difficult management problems for the ' pastoralisls who depend on the system for their livelihood. There is a considerable debate in relation to the likelihood or otherwise of global changes in rainfall regimes as a result of increasing temperature levels consequent upon higher concentrations of greenhouse gases (GHG) (for example Gordon el al., 1994, Mitchell and Williams, 1986; and Watson el al\ 1988). In addition there is a lot of uncertainty concerning the regional effects of such climatic changes upon agriculture (Parry and Carter, 1988; Mitchell el al 1996), and particularly on livestock production.
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    SOIL DEGRADATION AND SUSTAINABLE PRODUCTION OF SEMI-ARID PASTORAL SYSTEMS:THE CASE OF THE JAKUSKO-NASARE GRAZING RESERVE YOBE STATE, NIGERIA.
    (Department of Geography, Nasarawa State University Keffi, 2002-07-18) Ayuba, H.K.; Maryah, U.M.
    Grazing reserves in the semi-arid region or Nigeria were first proposed as a means of pastoral development during the colonial regime in the late 1940s. The main objective was to settle the I'ulani pastoralists in areas where livestock service could be rendered and crop production could be introduced to supplement household income while agricultural residues could provide fodder for (he herd. Unfortunately, such a policy did not take into consideration the long term effects of continued grazing on the reserves. This overgrazing which subsequently led to reduction in vegetation cover the development and acceleration of erosion and intensification of the process of range deterioration became eminent in the 1990s. This paper seeks to provide quantitative evidence on the extent of soil deterioration in one of the hugest grazing reserves in semi-arid Nigeria. It is hoped that the results of this study will help government to provide a policy that will create incentive for soil-preserving land management practice in the next millennium.
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    WEATHER VARIABILITY AND TEA YIELDS ON THE MAMBILLA PLATEAU, NIGERIA
    (Department of Geography, Nasarawa State University Keffi, 1999-07-18) Ayuba, H.K.; Maryah, U.M.; Dayya, S.V.
    Climate governs to a large extent the types of crop that could be. grown in a given area at a given time. With reference to tea production, the main climatic variables which influence the rates of shoot extension and ultimately the yield of tea arc temperature regimes, humidity, rainfall and evaporation (Carr, 1972; Squire and Calendar, 1981; Stephens and Carr, 1990a; Stephens el al., 1992). The effects of these variables on yield and its components have been well described and analysed in parts of tropical Africa (Stephens and Carr, 1989; Stephens el a/., 1992) and Sri Lanka (Fuchs, 1989), so that the ccophysiology of tea growth is fairly well known.