Carbon flow pattern in the forest zones of Nigeria as influenced by land use change

Abstract

Forest in Nigeria plays a much wider role in the overall balance of issues affecting the country than those of climate change alone. Nigeria’s tropical forest is depleting fast, due largely to uncontrolled human activities. Poverty, urbanization, population growth and insecurity are the major causes of this trend. Tracking carbon flow in these forest life zones will help account for the effect of these activities on the environment. COPATH, an acronym for Total Carbon Flow from Conversion to Agriculture, Pasture, Harvest and OTHER land-uses including construction of dams, roads, forest fires and human settlement, etc., was used for tracking carbon flow in the forest zones. From the five forest life zones, total carbon stored was estimated to be 2.55 TgC. The four activities of agriculture, harvest, pasture and bush burning were pronounced in contributions to land use changes, particularly to forest depletion. In this paper it is shown that carbon emission was highest from harvesting activity in year 2000, principally from clear-cutting activity in the lowland rainforest as against that of 1990 study, which showed agricultural activity as the major anthropogenic activity leading to carbon release into the atmosphere. Further, it is shown that the value of carbon emission is on the increase as compared to the earlier study with 1990 as the base year. During the two periods of study, it was however, observed that the relative contribution of each of the activities that are responsible for deforestation and affects carbon flow pattern in the forest zones and invariably causes carbon emission had not changed. Though a look at the fractional contribution of each of these activities in 2000 as against that of 1990 estimates shows a marked change. The study also concludes that if there is no change in the estimated deforestation rate of 2.23% per annum of the forest formations, lowland rainforest and riparian forests are likely to disappear by 2040.

Key words: Carbon flow pattern, forest life zone, land use, human activities, deforestation.