THINNING. 37 



the thinning out should be so sharp as to leave 

 every tree standing alone. 



The evil effects of neglected thinnings may fre- 

 quently be seen in artificial clumps of sissoo in the 

 Punjab, in which the trees have been allowed to 

 draw each other up until a dead-lock has set in, 

 and increment almost entirely ceased in all but 

 the outer trees of the grove, whose cubic contents, 

 taken singly, will sometimes equal that of half-a- 

 dozen of the poles within. 



After such a sharp thinning out as above indi- 

 cated, the forest floor is advantageously covered 

 with a shade-loving undergrowth or coppice. This 

 shades the ground from the direct rays of the 

 sun, preserves its moisture, enriches it with fresh 

 deposits of humus, thereby fitting it for the recep- 

 tion of a new crop after the timber shall have 

 been felled, and gives at the same time a money 

 return while the timber is growing. 



In Germany I saw the hornbeam much grown 

 under oak ; and for this country, the tun and mul- 

 berry are shade-loving trees with serviceable woods, 

 that might be advantageously grown under similar 

 conditions. 



The German forest officer, while directing thin- 

 ning operations, is always anxious to clear out all 

 trees of inferior classes that threaten to crowd out 

 more valuable timbers ; and by persistence in this 



