604 



AMERICAN F0RE:STRY 



at one time, normally transmit from 

 the leaves to the earth. 



It is not merely because they at- 

 tract precipitation of rain that trees 

 are valuable to climate and to pro- 

 ductiveness. In the forest soil that 

 they cover and make solid by their 

 root systems and enrich and mulch 

 with their decaying leaves, the rain 

 finds storage for much more than 

 can be absorbed by tree roots. 



This stored water, by slow per- 

 colation, trickles (without washing 

 or injury to the soil) from its 

 spongy reservoirs among the roots, 

 leaves, moist and cool depressions 

 in the forest glades, and feeds the 

 springs and water courses when 

 nature is athirst. In the same way 

 do trees preserve the snow from 

 sudden melting and hold it in 

 reserve for human needs. 



On the other baud, the treeless 

 country receives its diminished rain 

 ! torrentially, accompanied by violent 

 squalls of wind — the decomposed 

 TRYi.NG TO S.A.VE WHAT IS LEFT OF THE SOIL Vegetable matter and the surface 



Having no tree growth, no undergrowth, and no natural growth of any kind, these hillsin Chinahave to be subjected „^:i fUof lin^ K^^ait rlicintpcrra ti^rl intn 

 to the kind of artificial terracing shown in this photograph in the effort to save what little of the soil there is left. ^'-'"' '-"'"- "'^^ uecu ulblULCj,! dLCU UILU 



mellowness by sun and air, are 



multiplied by 6, 1000, the amount radiated out by every 

 square inch, gives us a number of ounces equaling 294 

 gallons, or more than eight barrels of moisture thrown 

 out into the dry air each twenty- four hours by each 

 large forest tree. Other trees that need more water 

 will, if growing nearby, absorb it from these generous 

 neighbors, as for example, the magnolia will dourish 

 at Los Angeles, California, if near other trees, but will 

 die if it be planted alone. 



In another and preeminently 

 important way, the leaf is con- 

 stantly at work for man. Its ser- 

 rated edges are tiny tentacles to 

 catch the electricity and send it 

 down to work vivifying elTects upon 

 the earth. The soil is energized by 

 this constant electrical stimulation. 

 It is proper to use the adjective 

 " constant " for the process goes on 

 all the time. Electricity is more 

 constantly tingling through the 

 fibres of a growing tree than it is 

 through a telegraph wire. It is a 

 mistake to suppose that the electri- 

 cal current ne\er touches the tree 

 save when it is said to be " struck bv 

 lightning." This bursting open of 

 the tree by lightning is only when 

 the attraction of the tree brings to 

 it, in highly charged electrical con- 

 ditions of atmosphere, more elec- 

 tricity than the trunk of the tree can. 



washed from the surface of the hills and sloping plains 

 and carried away into the sandy river beds (along with 

 the torrents of escaping water) to be lost in the sea or to 

 enrich some delta country far down the stream. In such 

 countries it frequently happens that great raging floods 

 pour down river beds — ordinarily dry-rivers, as one 

 miglit say, invisible in the dry season and inx'incible 

 in the wet season. 



.\RTIFICI.-\L TERR.\CI.\G I.\ CHIN.\ 



Showing the efforts of the Chinese to save what is left of the soil after the forests are gone. 



