s:630:"%T Knowledge for Great Green Wall Action (K4GGWA) %A CIFOR-ICRAF %X The drylands of the Sahel and the Horn of Africa face a tough combination of biophysical, anthropogenic and social challenges. In fact, they are now among the world’s most severely degraded and desertified regions. Simultaneously, around 135 million people in these regions depend directly on land resources, mainly for subsistence agriculture to support their food security. The needs to manage land sustainably, restore and rehabilitate it, and avoid further degradation are therefore vital to foster secure livelihoods for the regions’ communities. ";