An ambitious plan to build a vast forest belt straight across Africa to contain desertification has taken root in Senegal, greening huge tracts of land with drought-tolerant tree species. From west to east, the 15-kilometer-wide Great Green Wall (GGW) will span the continent from Senegal to Djibouti, passing through Mauritania, Mali, Burkina Faso, Niger, Nigeria, Chad, Sudan, Eritrea and Ethiopia. In all, the coast-to-coast forest will run 7,600 kilometers (4,750 miles). \"It is a crazy project, but a touch of madness helps when conceiving something which has never been conceived,\" Senegalese President Abdoulaye Wade said when he launched GGW at a conference of Sahel countries in 2005. Work on Senegal\'s section has made rapid progress since planting began in 2008, with various species of acacia trees stretching over 535 kilometers, covering around 15,000 hectares (37,000 acres) surrounded by 5,000 kilometers of firewalls. The idea of erecting a great wall of trees to stop the southward spread of the Sahara came amid UN forecasts that two thirds of Africa\'s farmland may be swallowed by Saharan sands by 2025. International agencies have pledged to invest more than three billion dollars in building the wall. In Senegal, the GGW is currently being funded almost entirely by the government to the tune of 1.4 million euros ($2.1 million) annually, but additional funding is expected from the European Union. Some 140 million euros will be needed to complete the Senegalese section, which runs through the northern Tessekere-Widu rural region, according to Matar Cisse, head of the national GGW agency. \"Initially, it was just a political idea. Here we added technical content adapted to the management of each eco-system in perfect harmony with rural populations,\" mostly ethnic Fulani herders, he said in an interview last month. \"It is a program to fight climate change, drought, poverty,\" said his deputy, Pape Sarr. In this semi-arid region where the rainy season lasts less than three months a year, locals remember the devastating droughts of 1970 and 1980. The GGW has transformed the area, with nurseries growing the various tree species to be planted, alongside fruit and vegetable gardens tended by local women. Water, a rare commodity, comes from wells, rain water basins and a branch of the river Senegal. Gilles Boetsch, an anthropologist from the French National Centre of Scientific Research (NCSR) hailed the GGW\'s positive impact on the environment, human activities, health and diet. He runs an observatory set up in Tessekere jointly by the NCSR and the Dakar-based Cheikh Anta Diop University, to study the project\'s impact. Malian and Burkinabe scientists are also involved. Lamine Gueye, a Senegalese professor studying the health impact of the green wall, however fears it may lead to a return of mosquitoes in a region where malaria was on the decrease. But he also noted that the influx of scientists and medical experts has given locals free access to medical care in an area where \"99 percent of the people had never seen a doctor.\" And every year hundreds of Senegalese students and foreigners now flock to Tessekere to plant trees and help develop this impoverished region.