IMPROVEMENT OF THE FOREST 219 



The returns from it must be sought in the maintenance 

 or improvement of the soil conditions and in the sus- 

 tained rapid growth of the trees. Without underplanting 

 the soil often suffers from loss of moisture and nourish- 

 ment, and the growth of the tree drops off. 



Underplanting is an intensive operation. So far as the 

 author is informed, it has not yet been practised in this 

 country. Such underplanting as has been undertaken 

 here has been for advance reproduction or for esthetic 

 purposes. 



Improvement Work in Irregular Stands 



In this country there are a great many second-growth 

 stands which are uneven-aged and irregular. Some of 

 these stands have resulted from very slow natural repro- 

 duction on old clearings. Others are the result of hap- 

 hazard cutting and irregular reproduction. Competing 

 with the best trees there are many trees of poor form and 

 of poor species, and many defective trees. Such stands 

 require thinnings to improve their composition and 

 growth. 



The stand is essentially immature. If there are old, 

 straggling trees which interfere with the stand's develop- 

 ment, thev are cut. The thinning further removes de- 

 fective trees of all classes, together with malformed trees 

 and poor species, except when the density is so poor that 

 they constitute an important part of the canopy. Crowded 

 groups are thinned by cutting intermediate and co-domi- 

 nant trees, and oftentimes a dominant tree is taken for 



