Threat Status of Commercially Exploited Trees in the Nigerian Rainforest

Francis E. Bisong^1*, Peter Buckley²

¹Department of Geography and Environmental Science, University of Calabar, Calabar, Nigeria.
²Department of Agricultural Sciences, Imperial College, Wye Campus, London, UK.

DOI: 10.4236/ojf.2014.45058                

Abstract

Unregulated commercial-scale exploitation of trees is an indication of the extent of threat to various tree species. The study examined the threat status of commercially exploited trees in the forest estates of South eastern Nigeria. Specifically, it identified tree species under threat, and categorized them into threat classes, as well as determined the rate at which exploited trees were slipping into extinction. The study utilized the IUCN’s threat categorization criteria, in determining the threat status of commercially exploited trees. This study combined both secondary and primary data sources generated through Forest Inventory records, Tree Felled Analysis records and Participatory Survey. Data such as population size and density of species, level of exploitation and threat sensitive social and ecological parameters were obtained and applied against the IUCN criteria. Twenty-eight (28) trees species representing Thirty-two percent (32%) of eighty-six (86) commercially exploited trees were identified as threatened, ranging from the Vulnerable to the Critically Endangered categories. The theory of small and declining population paradigms were found to be of relevance in explaining the processes. Nine tree species such as Triplochiton spp., Baillonella toxisperma, Pogaoleosa, Anopyxis spp. among others were considered to require urgent conservation attention. Recommendations are proposed to halt the process of decline in the biodiversity of exploited trees.

Keywords

Threat status, Commercial, IUCN, Exploited Trees, Endangered, Vulnerable, Threatened Species, Extinction

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Barbault, R., & Sastrapradjo, S. (1995). Generation, Maintenance and Loss of Biodiversity. In V. H. Heywood, & R. T. Watson (Eds.), Global Biodiversity Assessment (pp. 201-274). New York: Cambridge University Press.
[2]	Bisong, F. E., & Arokoyu, S. B. (2003). Agricultural Land Use Modelling and Deforestation: An Analysis of Proximate Drivers in South-Eastern Nigeria. Ghana Educational Media and Technology Association Journal, 5, 47-64.
[3]	Bisong, F. E. (2003). Deforestation Motivators by Small Farmers in Common and Protected Lands in South-Eastern Nigeria: A Factor Analytical Approach. Mathematics Connection, 3, 1-23.
[4]	Bisong, F. E. (2004). Population Deforestation and Biodiversity Erosion in the Context of Rural Agricultural Extenesion in South Eastern Nigeria. African Journal of Educational Studies in Mathematics and Sciences, 2, 91-105.
[5]	Bisong, F. E. (1999). Deforestation and the Erosion of Biodiversity in the Cross River State Rainforest, South Eastern Nigeria. Global Journal of Pure and Applied Science, 5, 241-250.
[6]	Chittaro, P., Kaplan, I., Kehler, A., & Levin, P. (2010). Trade-Offs between Species Conservation and the Size of Marine Protected Areas. Conservation Biology, 24, 197-206. http://dx.doi.org/10.1111/j.1523-1739.2009.01323.x
[7]	Deb, P., & Sundriyal, R. (2011). Vegetation dynamics of an old growth lowland tropical rainforest in North-East India: species composition and stand heterogeneity. International Journal of Biodiversity and Conservation, 3, 405-430,
[8]	Dunn, R. M., Otut, D. U., & Wong, J. L. G. (1994). Report of the Reconnaissance Inventory of High Forest and Swamp Forest Areas in Cross River State, Nigeria.
[9]	Eggers, B., Matern, A., Drees, C., Egger, J., Harattle, W., & Assmann, T. (2010). Value of Semi-Open Corridors for Simultaneous Connecting Open and Wooded Habitats: A Case Study with grand Beetles. Conservation Biology, 24, 256-266. http://dx.doi.org/10.1111/j.1523-1739.2009.01295.x
[10]	FDD (1994). A Strategy for Sustainable Conservation and Management of the Forest of Cross River State. Forestry Development Department, Cross River State, Calabar.
[11]	Flasse, S., Archer, D., Boschetti, L., & Abell, T. (2002). Rapid Appraisal of Forest Resources from Remotely Sensed Data in Cross River State, Nigeria. Final Report. CRSCFP, ERM & DFID.
[12]	Forest Resources Study (1999). NIGERIA: Cross River State, National Report Volume 1. FORMECU, Nigeria: Federal Department of Forestry.
[13]	Frankel, O. H., Brown, A. H., & Burdon, J. J. (1998). The Conservation of Plant Biodiversity. Cambridge: Cambridge University Press, p. 222.
[14]	Gavin, M. C., Solomon, J. N., & Blank, S. G. (2010). Measuring and Monitoring Illegal Use of Natural Resources. Conservation Biology, 24, 89-100.
[15]	Given, D. R. (1994). Principles and Practice of Plant Conservation. London: Chapman & Hall, 37-83.
[16]	Glowka, L., Burhenne-Guilmin, F., Synge, H., McNeely, J. A., & Gundling, L. (1994). A Guide to the Conservation on Biological Diversity. Environmental Policy and Law Report No. 30, IUCN: The World Conservation Union.
[17]	Hall, B. J. (1977). Forest-Types in Nigeria: An Analysis of Pre-Exploitation Forest Enumeration Data. Journal of Ecology, 65, 187-199. http://dx.doi.org/10.2307/2259073
[18]	Joseph, L., Maloney, R., & Possingham, H. (2009). Optimal Allocation of Resources among Threatened Species: A Project Priotization Protocol. Conservation Biology, 23, 328-338. http://dx.doi.org/10.1111/j.1523-1739.2008.01124.x
[19]	Lawrence, M. J., & Marshall, D. F. (1997). Plant Population Genetics. In N. Maxted, B. V. Ford-Lloud, & J. G. Hawkes (Eds.), Plant Genetic Conservation: The in Situ Approach (pp. 99-113). London: Chapman & Hall.
[20]	Lawrence, A., Afifi, R., Ahmed, A., Khahfa, S., & Paget, T. (2010). Bioactivity as an Options Value of Sea Cucombers in the Egyptian Red Sea. Conservation Biology, 24, 217-225. http://dx.doi.org/10.1111/j.1523-1739.2009.01294.x
[21]	Martorell, C., & Peters, E. (2009). Disturbance Response Analysis: A Method for Rapid Disturbed Areas. Conservation Biology, 23, 377-387. http://dx.doi.org/10.1111/j.1523-1739.2008.01134.x
[22]	Miller, K., Allegretti, M. H., Johnson, N., & Johsson, B. (1995a). Sustainable Use of Its Components. In V. H. Heywood (Ed.), Global Biodiversity Assessment UNEP. Cambridge: Cambridge University Press.
[23]	Miller, K., Allegretti, M. H., Johnson, N., & Johsson, B. (1995b). Measures for Conservation of Biodiversity and Sustainable Use of Its Components. In V. H. Heywood, & R. T. Watson (Eds.), Global Biodiversity Assessment. Cambridge: Cambridge University Press.
[24]	Nelson, F., Foley, C., Foley, L., Leposo, A., Loore, E., Peterson, D. et al. (2010). Payments for Ecosystem Services as Framework for Community-Based Conservation in Northern Tanzania. Conservation Biology, 24, 78-85. http://dx.doi.org/10.1111/j.1523-1739.2009.01393.x
[25]	Nicholson, E., Keith, D., & Wilove, D. (2009). Assessing the Threat Status of Ecological Communities. Conservation Biology, 23, 259-274. http://dx.doi.org/10.1111/j.1523-1739.2008.01158.x
[26]	Rylands, A., & Luna, E. R. (1995). A New System for Classifying Threatened Status. Neotropical Primates, 3, 109-112.
[27]	Stork, N. E., & Samways, M. J. (1995). Inventorying and Monitoring. In V. H. Heywood (Ed.), Global Biodiversity Assessment UNEP. Cambridge: Cambridge University Press.
[28]	Thogmartin, W. E. (2010). Modeling and Mapping Golden-Winged Warbler Abundance to Improve Regional Conservation Strategies. Avian Conservation and Ecology, 5, 12. http://dx.doi.org/10.5751/ACE-00426-050212
[29]	Underwood, J., D’Agrosa, C., & Gerber, L. (2010). Identifying Conservation Areas on the Basis of Alternative Distribution Datasets. Conservation Biology, 24, 162-120. http://dx.doi.org/10.1111/j.1523-1739.2009.01303.x
[30]	Wade, A., & Theobald, D. (2010). Residential Development Encroachment on U.S. Protected Areas. Conservation Biology, 24, 151-161. http://dx.doi.org/10.1111/j.1523-1739.2009.01296.x
[31]	Whittaker, R., Miguel, B., Araújo, M., Jepson, P., Ladle, R., Watson, J., & Willis, K. (2005). Conservation Biogeography: Assessment and Prospect. Diversity and Distributions, 11, 3-23. http://dx.doi.org/10.1111/j.1366-9516.2005.00143.x