Estimating wood charcoal supply to Toliara town in southwestern Madagascar, a comparison of methods

Abstract

Wood charcoal is the main energy source used by households in developing countries. However, due to the impact of wood charcoal production on forests, it is difficult to maintain a sustainable supply of wood charcoal for towns located in semi-arid environments. The supply of wood charcoal to the city of Toliara is a major challenge in southwestern Madagascar, the most arid part of the island. To design and assess the feasibility of initiatives to address these socio-environmental issues, an accurate estimation of the town's wood charcoal consumption is required. This paper aims to estimate the annual quantity of wood charcoal consumed in Toliara and to compare the errors associated with two estimation methods: (i) observation of wood charcoal flows on the main roads entering the town, and (ii) survey among Toliara wood charcoal traders (wholesalers and retailers). The first approach provided an annual rate of wood charcoal entering Toliara of 43 460 ± 2 017 t (mean±standard error). The second approach estimated annual wood charcoal consumption at 31 247 ± 3 337 t. The difference may essentially be explained by the fact that the first approach is more comprehensive and includes all possible wood charcoal flows whereas the second approach only includes those foreseen in the value chain model. The first approach gave more accurate results, but is more difficult to replicate as it is more time-consuming and requires more human and financial resources. Tree plantation was suggested to increase wood charcoal supply in Toliara town. About 56 000 ha of eucalyptus plantations would be needed to meet the current wood charcoal demand. Less than 500 ha of tree plantations have been done until now essentially due to willpower and organisational problems.

Keywords

• Consumption
• Dry forest
• Flow
• Trader
• Urban
• Xerophytic thicket