Periodical Literature. 261 



greater measure because of their higher and longer persistent in- 

 crease of value with diameter. Therefore, the management of 

 these species strives for greater diameter growth. This can be 

 obtained without too high rotations only by open position. On 

 better soils, the broad-leaved trees, with their greater ability of 

 reacting to light, guarantee a persistent "light increment," which 

 means that a close stand for oak and beech causes more or less 

 value loss. Schwappach says that in beech stands handled ac- 

 cording to the regular rule of thinning the sub-dominant growth 

 suffers serious value and volume loss. E. g., on the first three 

 site classes open stands showed increased production in timber- 

 wood of 15 per cent, for 100 year rotations, and 19 per cent, for 

 120 year rotations, as compared with the closed stands. 



What do we understand by light intensive stand manage- 

 ment? Differences of biological characteristics of species, dif- 

 ferences of site, and of objects of management prevent an answer 

 applicable for all cases. But in general we should take the 

 middle course between extremes. Borggreve's reform ideas in 

 selection thinning — to cut out the stoutest stems in order to stim- 

 ulate the rest — are not always practicable. If too old, the re- 

 maining stems are unable to take advantage of the increased light 

 supply. The advance growing and generally dominant trees not 

 infrequently have poor forms, e. g. beech and pine, and hold back 

 a number of neighbors still capable of development. The timely 

 removal of such trees means a final total increase in usewood 

 increment and value. The value of this "Hochdurchforstung," 

 thinning in the dominant, as opposed to the Niederdurchforstung 

 or thinning in the sub-dominant, especially for trees of spread- 

 ing habit like beech, oak, pine, has been proved in the Danish and 

 Heck's forests. Early but moderate thinning in the dominant is 

 advocated by Schwappach, to be followed by setting free the 

 best stems for oak in the 50 year; by severe thinning in the sub- 

 dominant for beech in the 70 year. 



Removing dominant trees means retaining a greater number 

 of stems in the young and middle age classes than is customary 

 with the old-fashioned Niederdurchforstung. One great advant- 

 age of this is the prevention of spreading crowns and short boles. 

 Further, until the stand has separated into height classes it is dif- 

 ficult to predict the ability of individual trees to use a larger 

 growing space to best advantage. So until then it is wise to keep 



