Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Sustainable use and conservation of yams in Ambositra-Vondrozo forest corridor, Madagascar.

Abstract

Context - This pilot project focuses on yam conservation in Ambositra-Vondrozo forest corridor (COFAV) through population studies of wild species and the adoption of new methods of cultivation of the introduced species Dioscorea alata L. Methods - The research was done in collaboration with local community associations. The project aimed to determine levels of exploitation of yams and their importance compared with other foods. Twenty village associations (Vondron'Olona Ifotony or VOI) were selected and enquiries were made in 700 households following training. Plots were established to track the population size of yams through the seasons. The project also helped selected communities and households to cultivate the 'ovibe' (Dioscorea alata L.), an economically viable alternative to travelling long distances to exploit wild forest yams. Key results - Wild yam species have become rare in COFAV due to forest fragmentation and unsustainable collecting of yam tubers for food. Moreover, knowledge of both cultivated and wild yams in this region is incomplete and currently there is no management plan to conserve yams in their natural habitat. Forty-three herbarium specimens of yams (Dioscorea spp.) were collected during inventory work. In parallel, 800 plants of 'ovibe' (Dioscorea alata) were cultivated by these VOIs, producing a total of 1 ton of tubers at the end of the growing season. Most VOIs decided to continue 'ovibe' cultivation at the end of the project. Their objective was to ensure sufficient food production to protect the wild yams and their sites from overuse. Conclusion - The modern cultivation technique for 'ovibe' (D. alata) adopted by the villagers was identified as the priority action for this project. Once this method of culture was established locally, visits to the forest decreased in frequency. This should allow the wild species to regenerate in their natural environment.