" Why is the forest such an effective agent in the prevention of soil erosion and in feeding
the springs and rivers? The forest does two things: (1) the trees and undergrowth break up
the rainfall into fine spray and the litter on the ground protects the soil from erosion; (2)
the residues of the trees and animal life met with in all woodlands are converted into
humus, which is then absorbed by the soil underneath, increasing its porosity and waterholding
power. The soil cover and the soil humus together prevent erosion and at the same
time store large volumes of water. These factors -- soil protection, soil porosity, and water
retention -- conferred by the living forest cover, provide the key to the solution of the soil
erosion problem." (An Agricultural Testament) "

― Albert Howard