206 



STUDIES OF TREES 



requires immediate attention. Otherwise, as time goes on, 

 it deteriorates more and more, the struggle for space among 

 the crowded and suppressed trees becomes more keen, 

 the insects in the dying trees multiply and disease spreads 

 from tree to tree. Under such conditions, the soil deteri- 

 orates and the older trees begin to suffer. 



FIG. 141. Second Stage of Deterioration. The Surface Soil of the 

 Wooded Area Has Washed Away 'and the Trees Have Died. 



The attention required for the proper care of woodland 

 may be summed up under the four general heads of soil 

 preservation, planting, cutting, and protection. 



Improvement by soil preservation : The soil in a wooded 

 area can best be preserved and kept rich by doing two 



