It's getting harder for villagers in the north of this dry West African country to find a favored ingredient for a traditional couscous dish — the fruit of the dimb tree.
The once-prevalent tree with its meaty fruit has disappeared from all but one village in an area the size of Connecticut, as shifting rainfall patterns have made northern Senegal drier and hotter, research has found.
Many tree species like the dimb are retreating from the Sahel, the arid region south of the Sahara Desert, losing ground to more arid species. In the zone that climate change scientist Patrick Gonzalez studied, the dimb’s range decreased 96 percent between 1945 and 1994 — from 27 villages to one.
Gonzalez said he looked at many factors, including population shifts and tree cutting, but "precipitation and temperature explained most of the variance in the data."
The greenhouse effect has warmed the southern Atlantic Ocean, source of the African monsoon, causing more rain to fall over the sea and less over the Sahel, said the Nature Conservancy’s Gonzalez, who did the research while with the U.S. Geological Survey.
Fig and firewood species also are dying, forcing women gatherers to range farther and spend more time hunting firewood. "Once you don't have that, people start burning cow dung. And that's when environmentally the area is in great trouble," Gonzalez said.