It is an oasis of greenery in the arid landscape of northern Senegal, on the border with Mauritania and its desert. About ten kilometers from the historic island of Saint-Louis, an educational and research agricultural farm is attached to Gaston-Berger University (UGB). Between the nurseries and the fields of market garden vegetables stand acacias, jatrophas and moringas, medicinal trees that are part of the botanical and therapeutic garden project led by three professors from the University of Saint-Louis.
Funded by the International Human-Environmental Observatory (OHIM) Téssékéré, an interdisciplinary research structure that allows an exchange of knowledge between scientists from the countries of the North and the South, this garden in the making is part of the Great Green Wall project. . The latter, supported by the African Union, aims to restore a vegetal strip 15 kilometers wide by 7,600 kilometers long, across eleven countries (from Senegal to Djibouti), in order to combat desertification in the Sahelian strip.
“The lack of ownership by the people is the big weakness of the Great Green Wall”says Dr. Sidy Mohamed Seck, associate professor of nephrology at UGB and one of the initiators of the project. “They don’t see the direct benefit of planting trees and then protecting and maintaining them, because the impact on climate change is not immediately visible. The idea is therefore to motivate them by planting trees with medicinal and food properties, which allow them to heal and feed themselves. »
Selection of ten plants
The therapeutic garden is only in its infancy, and the teams from the university are still waiting to have all the equipment to launch the seedlings and cuttings necessary for the development of the nursery. Once the seedlings have grown, the goal is to transfer them to a part of the agricultural farm, where they will stay while they grow stronger and adapt to the climate before being reintroduced to the Great Wall area. green.
“It’s interesting to do it in Saint-Louis, because we have the same climate, dry and arid, as that which prevails on the route of the Great Green Wall. It is a good place to experiment with the acclimatization of certain species”, explains Dr. Seck. In total, ten plants adapted to the Sahelian climate were selected, including jatropha or pourghère, a shrub that grows in semi-arid areas.
In addition to being able to produce biofuel with the oil extracted from its seeds, the populations use its sap, a translucent latex which heals wounds or treats diarrhoea. “This plant was used to form hedges, but with urbanization and the increasing use of fences, it is becoming increasingly rare”notes the doctor, who has specialized in herbal medicine for ten years.
Another star plant, vernonia is nicknamed “doctor” in Senegal, as its therapeutic virtues are numerous: it is recommended in case of fatigue, diabetes, infections, digestion or cholesterol problems… Rich in polyphenols which act on the cardiovascular system and cellular repair, vernonia contributes to the health of the respiratory system.
Essential research tool
In the agricultural farm, an alley of moringa has also begun to produce pods from which the students will come to harvest the winged seeds that Professor César Bassène manipulates with one hand. Teacher-researcher in agronomic sciences specialized in botany, he is one of the leaders of this project: “Moringa is tough, easy to replicate and nutritious. It is used against diabetes and its seeds purify poor quality water. It is a multipurpose plant! »he enthuses.
This specialist would like to go beyond the ten plants currently selected. “We are aiming for around thirty species in order to create a real collection of rare plants, endangered or threatened due to deforestation and urbanization”he explains, regretting the lack of space and means available to develop the project.
“The UGB is the second university in Senegal, but it does not have a botanical garden, which is nevertheless an essential educational and research tool. We want to preserve the living plants of northern Senegal, but also introduce local and exotic species in order to study them and manage the biodiversity of the plant world »he continues.
Its ambitions are great: protection of rare species, study of botany and plant pharmacy, research on the adaptation of exotic species, experimentation with multiplication methods, protection of diversity, education and awareness to fight against deforestation and overexploitation, opening of the garden to young people and students, creation of a herbarium and a seed bank… “But to carry out all these missions, we need new financial partners”emphasizes Professor Bassene.
The partnership with the OHIM already includes training for local people and students on the use of the ten designated plants, as well as an introduction to the food industry. Medical students are also included in the project to enable them to strengthen their knowledge of plants. The objective is that popular knowledge becomes scientific reality.