Landuse Change within Okomu and Gilli-Gilli Forest Reserves, Southwestern Nigeria: its climatic and societal implications

Ayanlade, A.  2016.  Landuse Change within Okomu and Gilli-Gilli Forest Reserves, Southwestern Nigeria: its climatic and societal implications. Tropical Ecology. 57(3):193-203.


The study evaluated the climatic and societal implications of vegetation
degradation in Okomu and Gilli-Gilli Forest Reserves (OGFRs) of Nigeria. Both remote sensing
and non-remote sensing data and methodologies were used. Landsat data between 1984 and
2011 were used as quantitative data while social survey was carried out for qualitative data
collection and assessment. Both remote sensing classification and Normalized Difference
Vegetation Index (NDVI) methods were used in this study. The results show that deforestation
resulting from farmland encroachment has increased in Okomu Forest Reserves (OFR) but was
relatively low in Gilli-Gilli Forest Reserves (GFR). In 1984, about 17 % of the reserves were
deforested, and this increased to 37 % in 2011 in OFR. These values reveal a massive
deforestation. Forest disturbance within the GFR is much less than OFR possibly because high
rate of illegal oil palm development in OFR. The result shows no significant impacts of
vegetation degradation on local climate, but people in the communities around the reserves
reported several climatic extreme events as a result of vegetation removal. However, the study
could not reveal direct significant impact of vegetation degradation on local climate but there
were rather indirect impacts from climate events. The results from social survey show that over
80 % of local people perceived high rate of heavy erosion and flooding mostly from year 2000 to
2011. It is obvious from the social survey that unrestrained felling of forest in the region has
also rendered the soil vulnerable to erosion and flooding since forests tend to reduce the impact
of erosion and floods. There is a need for proper enforcement of forest conservation laws in order
to reduce the rate of deforestation, not only in OFR and OGR but also in all forest reserves in
the country.