How can biodiversity be preserved while ensuring the economic livelihood of small farmers in Madagascar who grow vanilla? A study by the Universities of Göttingen, Marburg and Hohenheim shows that vanilla plantations on fallow land are not inferior to those in the forest in terms of yield and even promote biodiversity. The results were published in Nature Communications.
Researchers studied crop yields from vanilla agroforestry systems in northeastern Madagascar, the largest vanilla-growing region in the world, where smallholders are dominant. They compared the yields with the biodiversity represented by trees, herbaceous plants, birds, amphibians, reptiles, butterflies and ants. The study combined economic and environmental aspects of cultivation and showed that increasing vanilla yields had no negative impact on overall biodiversity. In addition, the yields of plantations on fallow land did not differ from those planted in forests.
dr Annemarie Wurz, the first author of the study, emphasizes that farmers don't have to clear land to achieve high yields. Instead, they could increase the biodiversity value of fallow land by growing vanilla there. In northeastern Madagascar, vanilla export is an important source of income for tens of thousands of small farmers. However, growing vanilla in forest instead of fallow land resulted in a 23% loss of all species, while endemic species decreased by 47%.
Denser vanilla plantings or longer vanilla plants increased yield but decreased tree and reptile species numbers. However, this did not have a negative impact on birds, amphibians, butterflies, ants and herbaceous plants. The study also showed that high tree density on plantations and in the landscape can increase biodiversity.
Conclusion: Promoting vanilla cultivation on fallow land is ecologically and economically significant as it contributes to the current UN Decade for Ecosystem Restoration. The study also shows ways in which biodiversity can be promoted and preserved outside of protected areas.
Source University of Göttingen