Ecology: Using fallow land to grow vanilla increases biodiversity

Using fallow land as agroforests for vanilla production in Madagascar increases biodiversity and opens up paths for conservation outside protected areas, suggests a study published in Nature Communications.

Madagascar has lost 44% of its old-growth forests within the past six decades owing to agriculture. The country is one of largest producers of vanilla, globally, despite the plant not being native to Madagascar and has to be pollinated by hand. Vanilla grows on top of tree bark, which requires farmers to plant trees or use existing trees for its production.

To explore the relationship between vanilla farming and forests, Annemarie Wurz and colleagues surveyed trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants and yields in vanilla agroforests (forests grown around or among crops) in Madagascar. In addition, they conducted interviews with local vanilla farmers. The authors find that in agroforests established in forests there were 23% fewer species and 47% fewer endemic species overall than found in old-growth forests. However, they found that when fallow land was used for vanilla agroforests there were 12% more species and 38% more endemic species than fallow land without agroforests.

The authors suggest that their findings highlight the potential for vanilla agroforestry to restore biodiversity to degraded and fallow lands. Agroforests planted on fallow land could secure farmers’ livelihoods while protecting Malagasy biodiversity and alleviate pressure on natural forests to be converted into agroforests, they conclude.