Trees Living Together 



THE COMMUNITY OF TREES 



JESSE H. BUELL 



A"> ONE gets farther and farther be- 

 yond the centers of population he 

 comes finally to the forests that human 

 activities have not changed to virgin 

 forests. In them, one can see better 

 what man has done to forests and how 

 he can more wisely mold them to his 

 benefit. In these manless forests, also, a 

 person comes to understand that a 

 forest is a changing, living community, 

 subject always to the forces of inani- 

 mate nature earth, air, sunshine, and 

 rain ; to the interaction within them of 

 plants and the animals ; to the changes 

 that forests themselves can effect in 

 their environment. 



Green plants are the engines for the 

 manufacture of the carbohydrates 

 the basic stuff that all vegetable matter 

 comes from, all animals live on, and by 

 which, ultimately, all of us are fed, 

 clothed, sheltered, and kept warm. A 

 forest is a vast battery of such engines. 

 In a single growing season an acre well 

 stocked with vigorous trees may pro- 



The drawing at the top of the page is of a 

 scene among the redwoods in California. 



duce 3 or 4 tons of useful wood, not 

 counting the additional unmeasured 

 pounds of the new growth on branches 

 and roots and in leaves, buds, flowers, 

 and seeds. The raw materials are car- 

 bon dioxide from the air, water and 

 mineral nutrients from the soil, and 

 warmth and energy from the sun. Of 

 these, only water and warmth are likely 

 anywhere on earth to be too scarce for 

 forest growth. Carbon dioxide makes 

 up only 3 parts in 10,000 parts of the 

 atmosphere, but unlimited fresh sup- 

 plies are continually brought by air cur- 

 rents. Mineral nutrients, although in- 

 dispensable, are needed in such small 

 quantities they make up only a small 

 fraction of the dry weight of trees 

 that they are abundant enough almost' 

 everywhere to keep forests growing. 



But forests use up vast quantities of 

 water. To make a summer's growth, 

 the roots of the acre of healthy forest 

 that grew 3 or 4 tons of wood may take 

 up from the soil 4,000 tons of water. 

 Much of this water, passing up from 

 the roots through the trunk, branches, 

 and leaves, escapes into the surround- 



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