STUDIES IN NATURE 



Now, if we go into a wood on a hot summer 

 day, we find that it is cool, and often notice 

 that the ground beneath the trees is moist, 

 although the land out in the open may be 

 almost parched up. Again, if we go into a 

 wood in winter-time, we find it warmer than 

 the fields, and very often it seems to have 

 entirely escaped the frosts. The leaves on the 

 trees shade the ground in summer-time, keep- 

 ing it cool and moist, preventing rapid evapora- 

 tion, while in winter-time the branches overhead 

 and the fallen leaves stop a great deal of the 

 radiation, and help to preserve the warmth in 

 the soil Trees also break the strength of the 

 winds and give shelter to the land around them ; 

 thus they add greatly to our own comfort, and 

 help towards the well-being of our flocks and 

 herds. 



If we look at the roots of a tree we see how 

 they spread out into the ground about them, 

 perhaps clinging to pieces of rock and so bind- 

 ing the soil together in a close mass. The 

 water during a rain-storm can only trickle slowly 

 and gently through the firm network of roots, 

 and cannot at once run off the land into the 

 streams, loosening and washing away the soil 

 with it In this way the trees with their roots 

 entangle the soil, which hi its turn holds back 

 the water, some of which remains in it while 

 the rest soaks gradually right down into the 

 earth. Floods are thus prevented or lessened, 



( 112) 



