Population distribution and threats to sustainable management of selected non-timber forest products in tropical lowland rainforests of south western Nigeria

Abstract: Uncontrolled harvesting of non-timber forest products

(NTFPs) poses a serious risk of extermination to several of these species

in Nigeria. Yet, there is a paucity of information on the distribution,

population status and sustainable management of NTFPs in most of the

tropical lowland rainforests. We, therefore, assessed the population,

distribution and threats to sustainable management of NTFPs within the

tropical lowland rainforests of Omo and Shasha Forest Reserves, south

western Nigeria. Data were obtained through inventory surveys on five

top priority species including: bush mango (Irvingia gabonensis (Aubry-

Lecomte ex O'Rorke) Baill), African walnut (Tetracarpidium conophorum

(Mull. Arg.) Hutch. & Dalziel syn. Plukenetia conophora),

chew-stick (Massularia acuminata (G. Don) Bullock), fever bark (Annickia

chlorantha Setten & P.J.Maas syn. Enantia chloranta) and bush

pepper (Piper guineense Schumach. & Thonn.). Purposive and stratified

random sampling techniques were used for the inventory. Each forest

reserve was stratified into three, viz: less disturbed natural forest (for

areas that have been rested for at least ten years), recently disturbed

natural forest (for areas that have suffered one form of human perturbation

or the other in the last five years), and plantation forest (for areas

carrying forest plantation). Data were collected from eighteen 10 m ×

500 m belt transects located in the above strata. The species were generally

fewer in both plantation and recently disturbed natural forest than the

less disturbed natural forest, suggesting that forest disturbances (habitat

modification) for other uses may have an effect on the occurrence and

densities of the NTFPs. Exceptions to this trend were found for P.

guineense and T. conophorum, which were fairly common in both planta