226 



WOOD AND FOREST. 



Every age has its own dangers. Many seeds never germinate, 

 many seedlings perish because they do not reach soil, or are killed by 

 too much or too little moisture, or by heat or cold, or shade. At the 

 sapling age, the side branches begin to interfere with those of other 

 saplings. Buds are bruised and lower branches broken by thrashing 

 in the wind, and their leaves have less light. Only the upper branches 

 have room and light, and they flourish at the expense of lower ones, 

 which gradually die and are thus pruned off. Some trees naturally 

 grow faster than others, and they attain additional light and room to 



spread laterally, thus overtop- 

 ping others which are sup- 

 pressed and finally killed, 

 beaten in the race for life. 



If the growth should re- 

 main about even so that the 

 trees grew densely packed to- 

 gether, the whole group would 

 be likely to be of a poorer qual- 

 ity, but ordinarily the few out- 

 grow the many and they are 

 called dominant trees. Even 

 then, they still have to struggle 

 against their neighbors, and at 

 this, the large sapling stage, 

 many perish, and of those that 

 survive there are great differ- 

 ences in size. Trees make their 

 most rapid growth in height, 



and lay on the widest yearly "rings," at the large sapling and small 

 pole age, Fig. 114, p. 263. It is at this stage, too, if the growth is at 

 all dense, that the young trees (poles) clean themselves most thoroly 

 of their branches. The growth in diameter continues to the end 

 of the tree's life, long after the height growth has ceased. 



When trees become "standards," and reach the limit of height 

 growth, thru their inability to raise water to their tops, their 

 branches must perforce grow sidewise, or not at all. The struggle 

 for life thus takes a new form. 



How trees are able to raise water as high as they do is still un- 

 explained, but we know that the chief reason why some trees grow 



Jngv74. oiiort- bodied w hite Oak of the 

 Open. Fort Lee, N. J. 



