138 THE PRINCIPLES OF HANDLING WOODLANDS 



her of seed-trees, evenly distributed and comparative- 

 ly close together. In consequence, a relatively large 

 amount of seed is produced, and is regularly distrib- 

 uted over the area. 



2. The system may be used with trees having heavy 

 seed, for the distribution of seed may be entirely con- 

 trolled by the number of seed-trees and their distance 

 apart. 



3. The shade of the remaining trees retards the 

 growth of grass, weeds, and brush, which would interfere 

 with the young growth of trees. 



4. The shelter acts as a protection to the soil, pre- 

 venting excessive drying and baking. 



5. The shelter protects the seedlings from drought 

 and frost. 



6. During the period of reproduction the trees left 

 standing are more or less isolated, and grow at a maxi- 

 mum rate, adding substantially to the final aggregate 

 yield and value. 



7. The new stand is established in advance of clear- 

 ing. As a result, there is not only a gain of several 

 years' growth, but the interval between removing the 

 cover of old trees and the formation of a close canopy by 

 the new trees is much shorter than in the clear-cutting 

 operations. The soil is, therefore, exposed for a mini- 

 mum length of time. 



8. The gradual clearing of a forest by successive thin- 

 nings is always less objectionable from an esthetic stand- 

 point than a clear-cutting. 



