164 OUR NATIONAL FORESTS 



know, the crowns of the trees intercept most of the 

 rain that falls; very little strikes the ground di- 

 rectly. The rain that strikes the crown is dissi- 

 pated on the leaves or needles, on the twigs and 

 branches, and on the trunk. It must travel a long 

 way before it reaches the ground, and all this delay 

 helps in preventing a rapid run-off or flood. The 

 soil in the forest is covered by a living ground cover 

 of flowers, shrubs and young trees, and by a dead 

 cover composed of leaves, twigs, dead branches, 

 fallen trees, all of which interrupt the raindrop's 

 journey to the ground. Even after the rain 

 reaches the ground, only a small part of it goes off 

 as surface run-off. The soil in the forest is loose 

 and full of holes and channels made by decaying 

 roots, earth worms, etc., so that the water is ab- 

 sorbed as fast as it reaches the soil. Also the soil 

 in the forest contains a large amount of organic 

 matter, resulting from decaying leaves and 

 branches, and this organic matter acts as a great 

 sponge, because it is capable of holding several 

 times its own weight of water. As a result of the 

 living and dead ground cover, the crown cover, and 

 the organic matter in the soil, the rainfall is fed to 

 the streams gradually through weeks and months, 



