[LUM#21] Let it grow

[LUM Magazine, Podcast] - Published on May 21, 2024 in Science-Society

What if we stopped replanting trees in cleared forests and let them regenerate naturally? Researchers have shown that natural forest regeneration is an effective way to reforest. This practice could be applied to cocoa farming, combining production with restoration.

While cocoa farming is the main cause of deforestation in West Africa, it also represents an opportunity to restore forest cover in producing countries through agroforestry. "This practice involves combining agricultural crops with forest trees. Cocoa trees originated as plants growing in the shade of South American forests, shade that can be provided by large trees, " explains Bruno Hérault, a researcher at CIRAD in the Forests and Societies unit.

But how can trees be reintroduced into these deforested cocoa plantations? "The most common practice at present is to replant young trees that are produced in nurseries. In Côte d'Ivoire, more than 10 million trees have been distributed to cocoa producers over the past 10 years," explains the tropical forest specialist.

Planting shock

Trees that do not always thrive in their new environments. After being cocooned, planting is a stressful experience that can sometimes prove fatal. "This planting shock can also be explained by the fact that trees grown in nurseries do not develop their roots as much as they would in a natural environment," explains Bruno Hérault. As a result, once replanted, most of them die or struggle to grow. This means that reforestation programs, which are very costly, have had mixed success.

However, there is an alternative: allowing trees to regenerate naturally. Bruno Hérault and his colleagues monitored more than 12,000 trees in the cocoa plantations of Côte d'Ivoire and found that allowing young trees growing in the fields to grow is more effective. "The forests were cut down just a few decades ago, so there are still many remaining trees scattered throughout the landscapethat were spared from logging, offering great potential for natural regeneration via the soil seed bank," explains Bruno Hérault. These spontaneous trees are much more resilient than trees from nurseries and have a better chance of developing properly.

Intimate relationship

Although this practice is more effective and less expensive than tree reintroduction programs, it still requires support for cocoa farmers, particularly in identifying young forest plants that grow spontaneously on their plots. "They need to be trained to help them recognize and choose the most interesting trees to preserve, " says the specialist.

An alternative that, for the researcher, offers opportunities far beyond economic and ecological benefits. "Farmers are thus able to envision the future of their land themselves, allowing them to take greater ownership of it. It is also a way for them to develop a closer relationship with their land, changing the relationship between humans and nature."

A first-rate solution that is struggling to gain acceptance among stakeholders in the cocoa industry. "In terms of visibility, it is always more rewarding to replant trees than to let them grow," laments the researcher, who advocates for the complementary nature of these practices. Natural tree regeneration could indeed contribute to efforts to restore forest cover, which currently covers 9% of the territory in Côte d'Ivoire, a country that is aiming for 20% by 2030.

Keywords: Forests, LUM#21, LumLu, LUM Magazine, Research, Science, Company