OUK FORESTS 7 



prepare their seeds for fall sowing. The members of the red-oak 

 group and many of the cone-bearing trees take 2 years to mature 

 their seed crops. 



The seeds of many trees are winged and are easily scattered by the 

 wind. The maples, and the American elm, are among those that be- 

 long in this class. The lighter seeds, like those of the elm, may be 

 borne long distances. The seeds of the maples, however, are com- 

 paratively heavy for fliers and consequently do not get very far 

 from the parent tree. Heavier seeds, such as the nuts and acorns, 

 may be carried away from the parent tree by birds and small animáis 

 which feed upon them. 



Most trees próvide great quantities of seed, but when the seeds 

 have fallen from the tree their fate becomes a matter of chance, and 

 out of thousands perhaps only one will take root where it can grow 

 to be a tree and in its tura bear seed (fig. 3). 



Figuee 4.— Young and oíd members of tree families. 

 Young trees are growing up under the protection of their parents. 



Relationship of Trees 



Forest trees are in many ways dependent upon their neighbors. 

 They increase the f ertility of the soil in which they grow ; and their 

 combined shade keeps the soil about their roots cooler in summer 

 than it would be if each tree stood alone. Their interlacing crowns 

 form a canopy under which the seedlings of all members of the 

 forest community are sheltered in early youth (fig. 4). 



At the same time there goes on in the forest a vigorous struggle 

 for the prime necessities of tree life — water, sunlight, and space in 

 which to grow. Battling to get ahead of each other, the large trees 

 push up towards the light, without which their leaves cannot digest 



220191 o — 40 2 



