The natural landscapes of Tchamba Prefecture in central Togo are mostly West Sudanian savanna — a mix of savanna, woodland, gallery forests, and some patches of denser forest. Much of the prefecture, including the area surrounding Tchamba town, experienced heavy deforestation during the 1990s as the area’s growing population cut trees for timber and energy, and converted areas of wooded savanna to farm fields. In an analysis of land cover changes between 1990 and 2010 conducted by Togolese government agencies and the University of Lomé, Togo measured an 18 percent loss of forest and 7 percent loss of woodland primarily to expanding areas of agriculture, residential growth and bushland (Kokou and others, 2012). However, recent trends measured by analysis of MODIS satellite data show some encouraging signs. Primary productivity (a measure of plant growth, see Land Productivity) showed a positive trend between 2000 and 2010 in some parts of Tchamba Prefecture.
The ASTER image pair (above) is focused on one of these positive developments. It reveals several areas of increased woody cover between 2000 and 2015 in the area surrounding Tchamba town. The high-resolution mage shows in greater detail what is behind this positive trend. Many of the areas that were being intensely farmed in 2000 with annual crops such as maize, sorghum, millet, rice, peanuts, cowpeas, soybeans, yams, cassava, sweet potatoes and cotton (Kokou and others, 2012) are now covered in trees. In many cases these are small-holder cashew plantations which use a system of integrating annual crops between the cashew trees (Tandjiékpon, 2010). As the trees mature and the amount of light reaching the annual crops diminishes, the crops change from cotton, yams and maize to crops that require less light. This intercropping system has been shown to be profitable for farmers, and the cashew trees help to restore degraded soils and sequester carbon (Opoku-Ameyaw and others, 2011; ACI 2010; Temudo and Abrantes 2014).
Agriculture directly or indirectly employs most of Tchamba Prefecture’s population but has been the cause of dramatic unsustainable land cover change over the past decades. Finding sustainable strategies for meeting the development needs of local people while still preserving productive soils and important ecosystem services, biodiversity, natural heritage and beauty of the savanna landscape is a major challenge for Togo’s policy makers. The successful intercropping of cashew and food crops may provide both short-term profits and long-term environmental benefits (Opoku-Ameyaw and others, 2011). In addition, a cashew processing facility was built in Tchamba town in 2005 and is providing hundreds of jobs and bringing new economic development to the community (African Cashew Alliance, 2013; Kokou and others, 2012).