Omo Biosphere Reserve, Current Status, Utilization of Biological Resources and Sustainable Management (Nigeria)

Isichei, Augustine O. (1995)

Technical Report

Omo Biosphere Reserve, which derives its name from River Omo that traverses it, is located between latitudes 6o35' to 7 o 05' N and 4o 19' to 4o 40' E in the Ijebu area of Ogun State southwestern Nigeria. The Reserve was constituted in 1925 and covers about 130 500 hectares, about 20 km from the Atlantic coast in its southern most parts. Geologically the Reserve lies on crystalline rocks of the undifferentiated basement complex which in the southern parts is overlain by Eocene deposits of sand, clay and gravel. The terrain is undulating and the maximum elevation of 150m above sea level is towards the west which the lowest parts of the Reserve are in the south where the River Omo joins River Oni, the Reserve's eastern boundary, before flowing into the Lekki Peninsular on the Atlantic coast. There are swamps in the south especially near the junction of the two rivers. The soil is tropical ferruginous (Ferric luvisol, according to FAO nomenclature). The mean annual rainfall ranges from about 1600 to 2000 mm with two annual peaks in June and September, with November and February being the driest months. The Reserve is in the mixed moist semi-evergreen rainforest zone. The northern parts of the Reserve is relatively dry forest with typical species such as Sterculia rhinopetala while Nauclea diderrichii and Terminalia superba are common in the wetter central parts. In the wet forests on sandy swampy soils in the south Lophira and trees in the Meliaceae family are common. There is a 460 ha Strict Natural Reserve (SNR) which was established in 1946 as a inviolate plot but later designated an SNR, in the north central area of the Reserve. An elephant sanctuary has recently been created around the SNR. Around the sanctuary and the SNR is the 'open' area of the Reserve where experiments and other treatments are located. There are about eight enclaves some of the fairly large inhabited by farmers and hunters in the open area. There is also a sawmill and a Gmelina plantation. Timber from the Reserve and Gmelina logs from the plantation support the sawmill while the Gmelina is also exploited as raw material for the recently commissioned Iwopin Paper Mill by Lekki Peninsular. Farmers practice wildlife in the Reserve for meat and several non-timber forest products. The farmers practice the Taungya system of farming whereby they participate in forest plantation establishment by nurturing tree seedlings during cropping on land allocated by the Reserve administering authority. Omo Biosphere Reserve, along with other reserves in the Nigerian forest zone has been used for studies on tropical moist forest regeneration with emphasis on 'economic' species and has since 1978 being the focus of the activities of the Nigerian Man and Biosphere (MAB), Theme One Project. Theme One is concerned with the 'Ecological effects of increasing human activities in tropical and sub-tropical forest ecosystem' and studies have been carried out on natural forest structure, plant and animal species composition, regeneration processes and response to treatments and human interference. There has been deep concern about the diminishing Nigerian forest estate and the rapid changes taking place in forest ecosystems including the socioeconomic activities of the people interacting with the changing forest landscape. The MAB studies have shown that conversion of natural forest to Gmelina plantation does not necessarily lead to total loss of biodiversity. Forest conversions are inevitable in the foreseeable future in view of current levels of wood demand and the issue of management of plantations for biodiversity sustenance deserves international research attention as non-timber forest products get more emphasis. Furthermore, the forestry sector is joining the emerging trend of privatization of management of natural resources. Already in Nigeria the benefits of private crop plantations are evident but the gestation period before private forests are harvestable has made private forests unattractive. Management of private and communal forests in a sustainable manner as opposed to subsistence farming should interest many tropical countries. Forest Reserves are locally controlled in Nigeria but the Strict Nature Reserves are managed by the forestry Research Institute of Nigeria (FRIN), Federal Government agency. There have been conflicts of interest arising from differences in perception of the roles of Reserves. This report discusses these conflicts in terms of biodiversity conservation and sustainable development. Recommendations are made on the management of Biosphere Reserves as exploitable economic resource on the one hand and as global life support systems on the other.