Periodical Literature. 529 



Dr. Schwappach reports on results of two 



Thinning sample thinnings in beech, one a selection 



Results thinning a la Borggreve, the other, close by, 



after according to old style in varying degrees, i. 



Borggreve e. without removing poorly formed domi- 



and nant trees. The thinnings were made in 



Others. 1886/7. Six areas were involved and the 



data and changes from time to time are 



noted in a table. 



It appears that the selection thinning as far as volume produc- 

 tion is concerned has won the day. 



At the beginning of the experiments the stands were even-aged, 

 75 years. The area, severely thinned, still contains 105 trees (at 

 97 years), among which branchy forms and double leaders, with 

 an average diameter of 14 inches, while the selection thinning has 

 reduced the number of trees only to 150 trees of only scant 12 inch 

 diameter with poorly developed crowns, hence the effect is as if 

 this area were younger than the other. But the increment of 

 the selection thinning area exceeds that of the severely thinned 

 by 2"/%. Although iioo cubic feet more wood had been removed 

 here, (3782 cubic feet against 2688), the cross section areas of 

 the two stands are nearly the same (248 against 268 square inches 

 in the severely thinned stand). 



The question arises, what now? At the last thinning in 1908 

 it was difficult to find sufficient number of poorly formed trees in 

 the stand which had been treated by selection thinning and now 

 the stoutest stem classes consist entirely of well formed, thrifty 

 individuals which have both satisfactory volume and value incre- 

 ment. Since a diameter of 16 inch is the most desired one, and 

 I inch in 10 years is all that can be expected, 25 years will be 

 required before the average tree will have secured that most 

 valuable dimension. Hence Schwappach is inclined to now apply 

 the French method par le has. 



Another set of thinning experiments in 76-year-old stands com- 

 prises (a) one severely thinned, (h and c) two opened up, and 

 (d) one treated according to Seebach's modified beech forest, 

 severely thinned and underplanted. Stand (a) was brought to 

 a cross section area of 265 square inches and kept there as near 

 as possible. In 1908, after the last thinning, it had still 234 



