Stock density and fruit yield of African walnut, Plukenetia conophora Mull-Arg (Syn. Tetracarpidium conophorum) in tropical lowland rainforests of southwest Nigeria

TO Amusa, SO Jimoh, IO Azeez, RO Awodoin, I Kareem

Abstract


Despite the huge socio-economic potentials of the African walnut, Plukenetia conophora Mull-Arg, there is a dearth of information on stock density and yield studies under different site conditions. Therefore, this study was carried out to investigate the stock density and fruit yields of P. conophora in three different habitats (i.e. less disturbed natural forest, recently disturbed natural forest and plantation forest) within Omo Forest Reserve (OFR) and Shasha Forest Reserve (SFR) of Nigeria. Stratified random sampling technique was used to carry out inventory survey. Fruit yields were determined by collecting fruit falls through double sampling approach. Both descriptive and inferential statistics were used in analyzing the data at P = 0.05. Stock densities of P. conophora were 5.33+1.7stands/ha, 14.67+2.05stands/ha and 16.00+2.94stands/ha in OFR, while they were 7.33+0.47stands/ha, 14.67+1.25stands/ha and 10.67+04.7stands/ha in SFR for recently disturbed forest, less disturbed forest and plantation forest respectively. There were significant differences in number and distribution of species by forest types, but not between forest reserves. The mean yield of P. conophora/ha/yr was estimated at 7,800.00kg for OFR and 6,534.00kg for SFR. Yields from plantation area contributed more in OFR, while yields from less disturbed natural forest area were higher in SFR. Yields from recently disturbed natural forest were consistently lower in the two reserves. These results show that P. conophora thrives better in plantation and old re-growth forests. This information is pertinent towards improving the management of the species, increase its productivity and enhance benefits in a more sustainable manner to the rural populace.


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References


Ajaiyeoba, E. O., Fadare, D. A. 2006. Antimicrobial potential of extracts and fractions of the African walnut. African Journal of Biotechnology 5 (22): 2322-2325.

Allen, B.P., Sharitz, R.R., Goebel, P.C. 2007. Are lianas increasing in importance in temperate floodplain forests in the south-eastern United States? Forest Ecology Management 242: 17–23.

Amusa, T. O., Jimoh., S. O. 2012. Determining the Local Importance of Non-Timber Forest Products Using Two Different Prioritization Techniques. International Journal of Agriculture and Forestry 2 (1): 84-92.

Awodoyin, R. O., Egunjobi, J. K., Ladipo, D. O. 2000. Biology, germination and prospects for the domestication of the conophor nut, Plukenetia conophora Mull. Arg. [Syn. Tetracarpidium conophorum (Mull. Arg.) Hutch. & Dalz.]. Journal of Tropical Forest Resources. 16 (1):30-38.

Bada, S.O. 1999. Community Participation in the Management of Omo Forest Reserve. Final Report for FORMECU, Federal Department of Forestry, Abuja, Nigeria. 44.

Dalziel, J. M. 1937. The useful plants of west Tropical Africa. Whitefriars Press, London.

Gianoli, E., Saldana, A., Jime´nez-Castillo, M. 2012. Ecophysiological Traits May Explain the Abundance of Climbing Plant Species across the Light Gradient in a Temperate Rainforest. PLoS ONE 7.6: e38831. doi:10.1371/journal.pone.0038831.

Hall, P., Bawa. 1993. Methods to assess the impact of extraction of non-timber tropical forest product on plant population. Economic Botany 47:234- 247.

Jimoh, S.O. 2002. A multiple use planning model for tropical rain forests: The case of Sasha Forest Reserve, Nigeria. Ph.D. Thesis submitted to the Department of Forest Resources Management, University of Ibadan, Nigeria. 248.

Jiofack T., Tchoundjeu, Z., Guedje N.M., Lejoly J., Fokunang C., Mate, M. 2013. Can the contribution of the African walnut diversifying cocoa agro forests being profitable for local stallholders in Cameroon? Wudpecker Journal of Agricultural Research 2.5:142 – 150.

Isichei, A.O. 1995. Omo Biosphere Reserve, Current Status, Utilization of Biological Resources and Sustainable Management (Nigeria). Working Papers of the South-South Cooperation Programme on Environmentally Sound Socio-Economic Development in the Humid Tropics. UNESCO, Paris. 52.

Samson S. E., Mitsan O., Samuel E. U., Yomi R. A., Alfred F. E., Comfort B. E. 2014. Antibacterial Activity of Methanolic Leaf Extract of Plukenetia conophora Mull. Arg. against Selected Bacteria Isolated from Urinary Tract Infection. International Journal of Microbiology and Application. 1 (1):1-10.

Siebert, S.E. 2004. Demographic effects of collecting Rattan cane and their implications for sustainable harvesting. Conservation Biology 18: 424-431.

Sunderland, T. C. H., P. Tchouto. 1999. A Participatory Survey and Inventory of Timber and Non-timber Forest Products of the Mokoko River Forest Reserve, SW Province, Cameroon. Report for USAID/CARPE. 43.

Swaine, M.D., Grace, J. 2007. Lianas may be favoured by low rainfall: evidence from Ghana. Plant Ecology 192: 271–276.

Udo, E.S., Olajide, O., Udoh, E.A. 2009. Life-form and Density of Valuable Non-timber Plants in Ukpom Community Forest, Akwa Ibom State, Nigeria. African Research Review 3.3:73-80.

Wong, J.L.G. 2000. The biometrics of non-timber forest product resource assessment: a review of current methodology. Research paper for the European tropical Forest Research Network (ETFRN), Department for International Development (DFID), UK. 109.

Wright, S.J., Caldero´n, O., Herna´ndez, A., Paton, S. 2004. Are lianas increasing in importance in tropical forests? A 17-year record from Barro Colorado Island, Panama´. Ecology 85:484–489.




DOI: https://doi.org/10.31357/jtfe.v4i2.2036

DOI (PDF): https://doi.org/10.31357/jtfe.v4i2.2036.g1121

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