Green wall helps Africa cope with desertification

African countries aim to plant trees into a wall nearly 8,050km long that runs across the entire continent, forming a natural barrier to prevent the Sahara desert from expanding.

The Great Green Wall project started in 2007 with a vision for trees to grow as wide as a belt across the vast Sahel region, from Senegal in the west to Djibouti in the east, by 2030. But Increased temperatures and reduced rainfall caused millions of crops to die off.

 Lemon garden in the village of Ndiawagne Fall in Kebemer, Senegal

Efforts to repel the desert continue in Senegal on a smaller scale. At the western end of the planned tree wall, farmer Ibrahima Fall walks under the shade of dozens of lemon trees. Surrounding the orchard and village was an isolated arid land. The lemon garden provides shelter from the heat and wind. Outside the village's low walls, the wind lifts sand into the air, promoting desertification, a process that turns fertile soil into desert, often due to drought and deforestation.

African countries have only completed 4% of the initial goal of the Great Green Wall project and need an estimated $43 billion to reach the rest. With the ability to build barriers on time very dim, organizers shifted focus from planting a large wall of trees to smaller, longer-term projects to prevent desertification, combining living improvements and helping the region. Agriculture is the most difficult.

"Projects that don't include communities are bound to fail," said Diegane Ndiaye, a member of the SOS Sahel organization that supports tree-planting programs in Senegal and many other countries along the Sahel. The Sahel is an area between the Sahara in the north and the more temperate African grasslands in the south. The program focuses on restoring the environment and revitalizing economic activity in villages in the Sahel, according to Ndiaye. With reduced rainfall and desert encroachment, this stretch of land is a very vulnerable region to the effects of climate change.

In Senegal's Atlantic coast, casuarina trees stretch from Dakar to the northern city of St. Louis, forming a "curtain" that protects where the Green Wall begins. The high canopy prevents strong winds from the sea. This reforestation project began in the 1970s, but many trees have been cut for timber and restoration work has only recently begun. People also plant trees in front of the dunes near the water source to prevent the sand dunes from moving.

Fall planted a lemon garden in 2016 and planted the plant near a water source on his property. Fall's Lemon Garden is among 800 small lemon groves in six communities in the town of Kebemer. Villagers use profits from orchards to replace straw houses with solid cement brick houses and buy more sheep, goats, and chickens. The village also installed solar panels to pump water from a common well, helping people to reduce their worries about water in the desert.

The President of the African Development Bank, Akinwumi A. Adesina, emphasized the importance of stopping desertification in the Sahel at the United Nations COP26 climate change summit and pledged to grant 6.5 billion USD for the Green Wall project by 2025.

The latest project in Senegal are circular gardens called "tolou keur" in Wolof, consisting of a variety of plants planned to allow larger trees to protect weaker ones. The outer perimeter of the garden is planted with moringa, sage, papaya and mango trees that are drought tolerant. These plants are planted so that their roots grow inward to improve the soil's ability to hold water. Senegal has a total of 20 circular gardens, each tailored to the soil, culture and needs of each community. Preliminary results show that this type of garden is growing well in the Green Wall area.