Spatial characteristics and economic value of threatened species (Khaya ivorensis)

Adenule O. Hamilton,Omonu Clifford,Opeyemi Adeyemi,Pasicha Chaikaew

doi:10.1038/s41598-020-63145-x

Abstract

Khaya ivorensis (K. ivorensis), one of the most valuable tropical hardwood species indigenous to West and Central Africa, has been classified as a threatened tree species. However, information on its remaining population and distribution are limited. We mapped the current K. ivorensis spatial distribution, modelled the spatial autocorrelation and estimated its economic value using volume estimation and market pricing. The study was conducted in Odigbo and Irele local government areas (LGA), Ondo State, Nigeria. Spatially, localities of 97 K. ivorensis were identified across the study area and can be added into a wide range of datasets from local to global inventories. Large trees in diameter and height were statistically clustered in the north of Odigbo and assumed to relate with forest reserve management. Estimated median tree volumes were 0.39 m3 and 0.31 m3 in accordance with the allometric volume function and specific volume function, respectively. The economic values of wood varied approximately from US$111,208 to US$72,081. Findings from this study are a valuable resource for conserving this species and other threatened tree species.

Highlights

Khaya ivorensis (K. ivorensis), one of the most valuable tropical hardwood species indigenous to West and Central Africa, has been classified as a threatened tree species
Khaya ivorensis (K. ivorensis), one of five species of African mahogany commonly found in coastal West Africa, Cote d’Ivoire through Ghana, and southern Nigeria to Cameroon, has been listed on the World Conservation Union (IUCN) Red List of Threatened Species since 19983
Estimating tree volumes from direct consumptive use can provide proxy economic values of K. ivorensis communities, which presented the value for the explicit use of forest; not necessarily the total value to nature

Summary

Introduction

Khaya ivorensis (K. ivorensis), one of the most valuable tropical hardwood species indigenous to West and Central Africa, has been classified as a threatened tree species. We mapped the current K. ivorensis spatial distribution, modelled the spatial autocorrelation and estimated its economic value using volume estimation and market pricing. Khaya ivorensis (K. ivorensis), one of five species of African mahogany commonly found in coastal West Africa, Cote d’Ivoire through Ghana, and southern Nigeria to Cameroon, has been listed on the World Conservation Union (IUCN) Red List of Threatened Species since 19983. Estimating tree volumes from direct consumptive use can provide proxy economic values of K. ivorensis communities, which presented the value for the explicit use of forest; not necessarily the total value to nature. This study aims to identify current K. ivorensis spatial distribution with structural information and estimate the economic value based on the market price of the wood. Spatial characteristics and valuation of K. ivorensis may not provide a full basis for decision, yet they can be supplemental considerations to better support sustainable management schemes and conservation efforts

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Results