The Yamba Berté Forest Reserve lies in the relatively humid Sudanian Region of southwestern Chad. The reserve protects an island of relatively intact dense shrub savanna, gallery forests, wetlands and small lakes (GEF, 2004). Forests including African mahogany, néré, doka, tamarind, African copaiba balsam and shea trees provide good habitat for a variety of fauna including gazelles, eland and other antelope as well as monkeys, ostrich, giraffe and possibly some of Chad’s remaining savanna elephants, among others (Chaintreuil and Conteau, 2000; IUCN, 2015). The reserve’s proximity to Sena Oura National Park and the adjacent Bouba Ndjida National Park in Cameroon with patches of intact forest between the two areas has historically made up a much larger area of contiguous habitat. The amount of intact forest remaining in the area between the national parks and Yamba Berté has declined between the dates of the two satellite images above.
Rainfall in the area averages around 1,000 mm per year, but in the long term it is quite variable having been as low as 600 mm and as high as 1,400 mm between 1971 and 2006. While the area is considered quite good for agriculture, as in many areas of the Sudanian Region, farmers have to cope with this interannual variability, compounded by uneven spatial and temporal distribution of rains (Sougnabé, 2013). In part due to the in-migration attracted by the good farming and herding conditions, the population just in the area shown in the above images has grown from around 700,000 in 1990 to an estimated 1,490,000 in 2015 (CIESIN, 2005). Most of this population makes its living by farming or a combination of farming and herding (Sougnabé, 2013). In addition to subsistence crops such as maize millet and sorghum, the area is ideal for growing cotton and groundnuts, the two primary cash crops in the area (FEWSnet, 2005).
The growing demand for land has led to encroachment on the forest reserve with two villages clearly visible in the 2015 satellite image, and many areas of encroachment around the perimeter of the reserve. Additional pressures on the forest include charcoal production, poaching and grazing of livestock. There are reports of at least two instances of oil exploration work in the area of Yamba Berté since 2003 (Oyamta and others, 2013). In the 1970s over 85 percent of the area shown in the above images was shrub savanna and less than 7 percent was agriculture. By 2013 only about 39 percent of the same area was intact shrub savanna, while the area being farmed had grown to just under 54 percent.