Symbioses.
Uganda is a safe port for many refugees. They are allowed to do some farming in the pine plantations after the third thinning. Only then there is enough light created on the ground to grow beans. Beans are of the family of leguminous and are nitrogen fixing. By farming in the plantation with so many people, there is more social control of illegal wood cuttings or fire outbreak. The owner of the plantation, the refugees, the pine trees and the beans, all of them benefits each other.