Browsing by Author "Ogunyemi, S."

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Climate change, impacts and mitigation: Nigerian experience
(2010) Ogunyemi, S.; Awodoyiu, R.O.; Olubode, O.S.
Climate has continued to change for millennia. The various anthropogenic factors have accelerated the change to the extent that what used to be subtle natural changes have become measurable and observable changes. These anthropogenic factors have resulted in the generation of greenhouse gases (GHGs) and their emission to the atmosphere and the depletion of the ozone layer. The GHGs, especially carbon dioxide (COz) generated from various combustion activities; methane (CHf generated from rice paddies and flooded areas as a result of anaerobic fermentation, and from ruminating cattle and nitrous oxide (NfO) generated from decomposition of nitrogen fertilizers and livestock wastes trap some of the heat (infrared) that radiate from the earth. The ozone layer at the upper stratosphere which shields the earth specifically from the ultraviolet (UV) light is constantly being destroyed by the immense quantities of chlorine released by volcanoes and other natural emissions, and by chlorine releasedfrom human-made chlorofluorocarbons (CFC, HCFC, HFC, PFC). The most visible effect of climate change is global warming, which has disrupted the thermodynamic balance of the earth, with some regions unnaturally gaining more heat than the others. This rise in earth temperatures has resulted in continued melting of ice caps, glaciers and sea ice, resulting in a rise in global sea levels of between 20cm and 60cm. The Nigerian Niger Delta is under threat of climate related flooding, habitat destruction and species loss. The coastal erosion in the Niger Delta occasioned by sea-level rise is already a menace, especially, regarding destruction of mangrove vegetation which constitutes an important stabilizing system in the brackish ecosystem. Already, 18,803 square kilometers was reported destroyed and 0.21 million people displaced by up to 2-meter coastal sea-level rise. The receipt of increased UV on earth not only increased the temperature on earth, but has serious implications on human health, causing melanoma skin cancer, cataracts and sunburn and altering human's immune system. Afforestation, reforestation, zero-tillage, replacement offossilized fuels with environment-friendly fitels and energy sources like bio-diesel and sustained public awareness programmes are suggested as ways to mitigate the emission of GHGs.
Diversity and proximate composition of herbaceous components of old oyo national park, nigeria in relation to wildlife conservation
(2009) Olubode, O.S.; Awodqyin, R.O.; Ogunyemi, S.
The diversity of wildlife in Parks depends on availability and distribution of flora feeding resources. Abundance and proximate relationships between wild plants and wildlife may determine conservation potentials of a Park. The composition and diversity of species in three wetlands (Ibuya, Ipade-Aya and Ajalcu) in Old Oyo National Park, Nigeria were studied in dry (February-March) and wet (September- October) seasons of 2004-2006. Herbaceous flora of the three wetlands were systematically assessed using 5000 m2 plots on which two 100 m diagonal transects were superimposed to enumerate all low-growing plants that rooted within thirty randomly selected 1 m2 quadrats. Four most abundant plant species in two families were selected for proximate analyses. Three topsoil samples of each site were randomly collected and analysed for physicochemical properties. Hyparrhenia involucrata Stapf. and Andropogon tectorum Schumach were the most abundant herbs in the wetlands. Ipade-Aya had the highest Shannon-Weiner (H1) and evenness (J) values of 1.6 and 0.7 respectively. Ibuya had H'=1.0 and J=0.5; while Ajalcu had H'=1.0 and J=0.5. The protein contents of the forage grasses significantly (P<0.05) ranked in the order: Andropogon tectorum > Andropogon gay anus Kunth > Hyparrhenia involucrata > Hyparrhenia rufa (Nees) Stapf. Soils of the wetlands were mostly similar, except Ajalcu which was sandy loam. Fauna populations at the three sites were low. The highest detected faunal populations were nine at Ibuya, and three each at Ipade-Aya and Ajaku. Available nutritious grasses may not continue to sustain wildlife populations. Further research should consider increasing forage for faunal conservation.
Floral diversity in the wetlands of apete river, eleyele lake and oba dam in Ibadan, Nigeria: its implication for biodiversity erosion
(2011) Olubode, O.S.; Awodoyin, R.O.; Ogunyemi, S.
Wetlands in Nigeria face constant threat of destruction by urbanization, road construction and agricultural activities, but the floristic compositions of these fragmented communities are unknown. A comparative assessment study of the floral of three wetlands in a forest-savanna transition ecological zone, Ibadan (70261 N, 30541 E), Oyo State, Nigeria was conducted in the dry and wet seasons of 2002 to assess their species richness, density, community structure and diversity. Thirty-eight plant species from 19 families were enumerated in the three wetlands in two seasons. Nineteen species from 13 families were enumerated in the dry season, while 14 species belonging to nine families were enumerated in the wet season. Eight families were common to both seasons. Eleyele and Apete wetlands had relatively stable flora for both seasons, while Oba dam exhibited pronounced shift in flora between the dry and wet seasons. Continuous perturbation of the three wetlands encouraged proliferation and dominance of some invasive species at the expense of indigenous species populations, leading to subtle biodiversity erosion
Floral diversity in the wetlands of apete river, eleyele lake and oba dam in Ibadan, Nigeria: its implication for biodiversity erosion
(2011) Olubode, O.S.; Awodoyin, R.O.; Ogunyemi, S.
Wetlands in Nigeria face constant threat of destruction by urbanization, road construction and agricultural activities, but the floristic compositions of these fragmented communities are unknown. A comparative assessment study of the floral of three wetlands in a forest-savanna transition ecological zone, Ibadan (70261 N, 30541 E), Oyo State, Nigeria was conducted in the dry and wet seasons of 2002 to assess their species richness, density, community structure and diversity. Thirty-eight plant species from 19 families were enumerated in the three wetlands in two seasons. Nineteen species from 13 families were enumerated in the dry season, while 14 species belonging to nine families were enumerated in the wet season. Eight families were common to both seasons. Eleyele and Apete wetlands had relatively stable flora for both seasons, while Oba dam exhibited pronounced shift in flora between the dry and wet seasons. Continuous perturbation of the three wetlands encouraged proliferation and dominance of some invasive species at the expense of indigenous species populations, leading to subtle biodiversity erosion
The potentials of farmers’ indigenous knowledge for the control of plant diseases.
(2000) Fadina, O. O.; Ogunyemi, S.
For the whole world to achieve the most desired sclf-sufficiency in food production, plant protection technologies must continuously be developed and used in food production process to battle against prevailing insect pests and diseases, weeds, vertebrate pests and menace of birds. These technologies must reach the primary producers who must be able to use them effectively and efficiently. However, a host of technologies have been developed which arc actually not being used by resource poor farmers who still produce the bulk of food in the developing countries. In Nigeria for example, Olayidc et al (1980) reported that 98% of the food consumed is produced by small-scale farmers who cannot afford Capital and input intensive crop protection approach. Strategies must therefore be developed to make sure that plant protection technologies be developed from farmers indigenous knowledge and selected modern technologies.