Explanation:

 Trees and forests are essential to the lives of people and animals in drylands. They can supply many of the basic needs of human communities, such as food, medicine, wood, energy, and fodder for livestock. In drylands more than in most other biomes, however, the demands of human communities have been much higher than the capacity of ecosystems to deliver sustainably, resulting, in many places, in the rapid depletion of these resources, leading to land degradation and desertification.