Potential of agroforestry techniques in mitigating CO2 emissions in Nigeria: some preliminary estimates

This paper attempts some preliminary evaluation of the potential of agroforestry techniques as a forestry strategy for controlling atmospheric CO₂—a critical greenhouse gas. The end-use scenario that attempts to meet the wood and related needs of the nation while mitigating climate change was adopted. The net emission estimate for the Forestry Sector in 1990—the base year for the study—was 9.5 million tonnes of carbon (MtC). Based on this figure, projections into the year 2030 gave cumulative net emissions of 427.4 and 580.5 MtC at 1.3% and 2.6% deforestation rates respectively. However, mitigating with agroforestry techniques, assuming that about 76% of the estimated 39.5 million ha of farmland in the country is committed to a variety of agroforestry systems, the results show that a total of 1530 MtC can be withdrawn from the atmosphere by the year 2030. The paper concludes that there is a reasonable case for the use of agroforestry techniques in the country, both as a means of sustaining soil productivity and as a strategy for mitigating climate change.     

Measurement of tree diversity in the Nigerian rainforest

The diversity of trees 5 cm in diameter and above at breast height was studied at five sites within the Nigerian rainforest. The sites were Gambari, Oban, Omo, Owan and Sapoba forest reserves. Diversity was measured in terms of similarity and heterogeneity and explored at beta and gamma levels. Over 315 species were encountered during the study. In terms of species richness, there are 80, 226, 163, 137 and 159 species in Gambari, Oban, Omo, Owan and Sapoba, respectively. The occurrence of the species showed that, while 26 species are common to all the sites, 62, 17, 15, 8 and 6 species are restricted to Oban, Omo, Sapoba, Gambari and Owan, respectively. Ordination by detrended correspondence analysis indicated gradients along the first two axes. The first axis reflecting rainfall gradient which decreases from Oban through to Sapoba, Owan and Gambari. The second axis showed a separation of Omo, and Owan and Sapoba. This suggests a gradient of soil parent materials, the former site is on the basement complex while the latter is on the cretaceous rock. It is suggested that each forest should be managed based on its particular characteristics, such as species composition and abundance. Thus, forests with high species diversity but fewer numbers of individuals, such as in Oban, should be earmarked for conservation while species-rich forests with relatively more economic species, as in Sapoba and Omo, should be managed for sustained timber production. Floristically poor forest, such as those in Gambari and Owan, should be converted to plantations of fast growing species but with care taken to avoid exposing such sites to soil erosion.     

Baseline levels of elemental concentrations in whole blood,plasma, and erythrocytes of Nigerian subjects

Biological Trace Element Research - In this pioneering effort on Nigerians, the arithmetic means, ranges, and standard deviations for the concentrations of the 13 elements, Br, Ca, Cl, Cu, Fe, K,...     

Arterial Pressures in Rural and Urban Populations in Nigeria

Surveys of arterial pressure carried out in rural and urban communities in Western Nigeria showed a steady rise in systolic values with age, this trend being less marked with diastolic pressures. Blood pressure levels were similar in women from rural and urban areas, but seemed much higher in urban than in rural men. The incidence of proteinuria was lowest in the female urban group. In general, the incidence of proteinuria or glycosuria was low and did not appear to be related to the blood pressure.