Trees make the soil fertile and also protect it by following ways:
i)The leaves, fruits, flowers and the remains of the tress fall on the ground (soil) and add organic matter to the soil, thus making it fertile.
ii)The roots of the tree absorb the underground water and prevent the soil from drying.
iii)The roots of the tress hold the soil tightly and prevent soil erosion.
iv)They improve the structure of the soil.
v)They assist in nutrient cycling.
vi)They provide protection from wind and water.
vii)Trees increase infiltration.