scholarly works

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End date: 2009

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    GROWTH PREDICTION IN SOME PLANTATIONS OF EXOTIC TREE SPECIES IN THE NORTHERN GUINEA AND DERIVED SAVANNA ZONES OF NIGERIA
    (1985-06) ADEGBEHIN, J. O.
    Growth studies which include diameter distribution using the Weibull function, development of stand volume models, and construction of provisional top height-age and total volume production-age curves for the average site class were carried out in plantations of Eucalyptus cloeziana, E. tereticornis and Pinus caribaea. The study locations were Kabama (Zaria) and Afaka (both typical of Northern Guinea savanna zone of Nigeria), Nimbia (Derived savanna zone) and Miango, Vom and Ta-Hoss (on the Jos Plateau). E. cloeziana represented only at Afaka had 4 experimental sample plots with age range of 4.2 - 15.5 years. E. tereticornis represented at Kabama and Afaka had 6 sample plots with ages from 3.7 - 15.5 while P. caribaea represented in all the study locations except Zaria had 43 plots with ages between 4.7 - 29 years. In fitting the Weibull distribution to the individual diameter plot data, WWINGO, the most suitable Weibull (program) subroutine for determining the Weibrill parameters in the stands, was capable of describing the diameter distribution in the plots as from the minimum age of 4 years for E. cloeziana and 6 years each for E. tereticornis and P. caribaea. On testing the Weibull parameter predictive models constructed (based on stand attributes and site factors) in new stands, while those of E. cloeziana and E. tereticornis gave good predictions as from the respective minimum age limits stated above, those of P. caribaea did not give reliable predictions until the age of 10 years. With reference to the stand volume model developed for each species, that of E. cloeziana gave the best prediction with the root mean square error (RMSE) of 2.25 m3/ha, followed by that of E. tereticornis with RMSE of 4.7 m3/ha and that of P. caribaea with RMSE of 10.1 m3/ha. The models predicted well within the range of field data when tested in new stands. Out of the three functions used in fitting the provisional top height-age (site index) curve for the average site class for each species, the Gompertz model, in most cases, gave better fittings than the Logistic while the polynomial function was the poorest. Based on the best-fit model for each species and some other criteria, a provisional average site class was defined as top height of 27.4 m at a reference age of 13 years for E. cloeziana, 24.8 m at the age of 15 years for E. tereticornis and 23.4 m at age 20 for P. caribaea. The Gompertz model was also more reliable than the Logistic in fitting the provisional average total volume production-age curve for each of the species. A maximum total volume production of about 240 m3/ha at age 13.4 years, 286 m3/ha at age 19.4 years and 726 m3/ha at age 30 could be obtained for E. cloeziana, E. tereticornis and P. caribaea, respectively, on an average site. The applications of the Weibull parameter predictive models in forest management, and the expected optimum rotation ages for the species in view of the growth figures obtained from the other growth models were discussed.
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    Prospects and challenges for incorporating trees into urban infrastructural developments in Nigeria
    (2008) Ajewole, O. I.
    Nigeria’s major cities are characterised by huge and growing social and environmental problems,such as air, land and noise pollution; non-conducive local micro climatic conditions; and stressful social and psychological living environments. These result from in- adequate, dilapidated and overstretched infrastructure, degraded urban physiognomy, increasing levels of unemployment, crime, insecurity and other social vices. These, in addition to inherent technical and economic constraints, make the in corporation of trees into the social and physical fabric of overall planning of towns and cities in Nigeria imperative. This is a natural and cost-effective means of alleviating environmental, social and economic problems in many of the Nigerian major cities. Successful integration of trees/ forests into overall urban planning will require the development of appropriate information, policy, administrative and legal frameworks, enlistment of social and political support, as well as appraisal of technical feasibility and environmental suitability of incorporation into the urban landscape. More importantly, sustainable urban forestry development in Nigeria will of necessity require the availability and readiness of NGOs to spearhead an urban forestry movement in the country.
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    Reconnaissance Survey of The Wildlife Sanctuary of Stubb’s Creek Forest Reserve, Akwa Ibom State, Nigeria
    (Government of Akwa Ibom State, Nigeria Ministry of Environment, 2004) Popoola, L.; Jimoh, S.O.; Alarape, A. A.
    This study was conducted at the instance of the Honourable Commissioner, Ministry of Environment, Akwa Ibom State in realization of the need to assess the potentials of wildlife in the Stubbs-creek forest reserve of Akwa-Ibom State, Nigeria. The terms of reference included, but not limited to provision of information on status of fauna and flora in the forest reserve, bearing in mind the level of human interference that had occurred in the last one decade. Using a combination of standard methods wildlife, vegetation and questionnaire surveys were conducted in and around the forest reserve to obtain information on the status of the major plant and animal lives and the various sources of threat to their sustainable management. Results obtained from the study indicate large- scale disturbance of the biophysical environment (flora and fauna) arising from such human activities as farming, illegal logging, oil prospecting and exploration. These have affected the hitherto rich fauna and flora of the reserve. The study still identified the existence of over 80 important plant species, which include Alcornea cor difolia; Raphia spp; Anthocleista nobilis;; Rhizophora racemosa; Gmelina arborea; Costus afer; Chromolina odorata; Rauvolvia vomitoria; Calamus spp; Musanga cercopioides; Albizia spp; Selaginalea spp. Species with moderate frequency of occurrence include Carpolobia lutea; Napoleona vogelii; Allablackia floribunda. They were distributed within the natural lowland rainforest, oil palm and raphia bushes and the mangrove. Over 90 animal species including rodents, reptiles, birds and monkeys were encountered. They include Thryonomys swinderianus, Potamochoerus porcus, Trangelaphus scripus; Python sebae, Crocodilus spp, Neophron monachus, Milvus migrans, Streptopelia senegalensis, Apus affinis,, Egretta alba, Ardeola ibis, Scopus umbretta, Neophron monachus The potential of the wildlife sanctuary for ecotourism is still quite high particularly with the existence of oil prospecting and exploration concerns that attract heavy human traffic into the area. Also there exist standard hotels within 30km radius of the forest reserve, which will encourage visitors to combine business with pleasure. There is however the urgent need to: secure the boundaries of the sanctuary, carry out a feasibility study and environmental impact assessment with a view to having comprehensive information that will form the basis for re-investment by the State government and also set the template for the development of proposals for donor assistance from international donor/investment agencies, win the confidence of the settlers in the adjoining communities, seek local and external partnerships for the management of the sanctuary and; Finally, the institutional and legal frameworks of the reserve should be clearly spelt out to enhance sustainability. The Sanctuary has the potential to boost the Poverty Reduction Strategy Programme (PRSP) of the State Government and should therefore be rehabilitated
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    The contributions of forestry sub sector to economic development in Nigeria: A case study of Ekiti state
    (2006) Arowosoge, O. G. E; Ajewole, O. I.
    One of the major problems facing forestry development in Nigeria is the under-valuation of forestry contribution to national economic development. This study therefore examines forestry contribution to the economic development of Ekiti state from 1997-2006. Primary data were collected with the use of well structured questionnaires and interviews with top management staff and divisional forest officers of the State, while secondary data were gathered from classified documents of the State Forestry Department (SFD).. The study observes that sawmills and timber contracting are the only forest based enterprises that are registered with the SFD. The 153 sawmills in the state employ about 2,085 people while there are 179 timber contractors. The results reveal that forestry contributed a total sum of N333,950,675 to the state's Internally Generated Revenue (IGR), while the state spent only N21.7 million for forestry development over the ten year period of study. The percentage contribution of forestry revenue to the state's total IGR ranges between 4 and 26% in 1997 and 2006 respectively. The programmes used for the development of forest resources inn the state include: Timber Development Law, Taungya System, Forestry Trust Fund, Ecological Project and Woodlot Development Project. Forestry has great potential to contribute to economic development of Ekiti State; however, inadequate forestry expenditure is a major constraint to the realisation of this potential. Forest managers will therefore have to evolve strategies to elicit greater commitment from the state government to fund forestry projects.
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    Urban-rural differential in food consumption in Nigeria: A case study of Ilesa and Atakumosa LGAs of Osun state
    (Taylor & Francis, 2006) Ajewole, O. I.; Omonona, B. T
    This study focused on the differential in food consumption between urban and rural households in Osun State, Nigeria. The data used in the study were obtained through the use of a structured questionnaire administered to randomly selected food consuming households in the Ilesa and Atakumosa local government areas (LGAs) of Osun State. The analytical tools used include descriptive statistics and ordinary least squares (OLS) regression. The study revealed that urban households have higher levels of per capita food expenditure than their rural counterparts. In addition, household size and the income and educational level of the household head are significant determinants of food consumption among urban dwellers. On the other hand, in rural households, only the income of the household head was significant in determining food consumption.
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    Non-timber forest products’ marketing in Nigeria. A case study of Osun state
    (2006) Aiyeloja, A. A; Ajewole, O. I.
    Research on markets and marketing of some non-timber forest products (NTFPs) was carried out in selected locations of Osun State. The NTFPs considered are chewing sticks such as Massularia acuminata and bush meat like Thryonomys swinderianus, representing both the flora and fauna aspects of NTFPs, respectively. Five Local Government Areas were randomly selected, namely; Odo-otin, Boripe, Iwo, Irewole and Atakunmosa for the research purpose. A total of 300 questionnaires were administered, 150 questionnaires for each of the NTFPs. Each NTFPs was further subdivided to production, marketing and usage or consumption with 50 questionnaires for each unit. It was gathered from the result that M. acuminata tops the list of the well favoured chewing sticks. Other types of chewing sticks that rank high include fagara (Zanthophylum zanthoxonoides) and Ira (Rauwolfia vomitora). Bush meat is also cherished by people most especially in urban centres where it is regarded as a delicacy. Despite the preference of bush meat, the rate of consumption is still low relative to other animal protein sources. Apart from these two NTFPs, several others of economic, nutritional and medicinal importance exist. A list of some of them is made with their uses. NTFPs are grossly affected by seasonal changes and this in turns affect their availability and prices. In all, considering NTFPs in the light of economic gain alone will be parochial even though analysis for the marketing of the two NTFPs shows that they are viable business ventures. The values should extend beyond the economic gain to other values which are indispensable to the existence of man. A major but neglected aspect is the medicinal aspect of NTFPs.