76 SUMMARY OF THE PROGRAMME [76] 



New investigatioris. 



Experiments with different methods of selection, especially on the research 

 domains (S); investigations on the possibility of developing suppressed shrubby 

 spruce ("marbuskar") and young spruce stånds, who have grown up too densy 

 ("stavagran"), (S); experiments in order to increase the growth of suppressed 

 pine plants on the pine heaths of the research domains (S); soil treatment 

 experiments in older stånds of pine on the research domains, in order to 

 get natural reproduction under shelter (S). 



c) Forest cultural operations. 



Continued investigations. 



The age of the clearing most suitable for cultivation in Norrland (F, N 

 and S); comparison between different methods of sowing in different types 

 of spruce forests, more or less affected by acid humus (F); comparison be- 

 tween different methods of planting (F); studies on the influence of varying 

 the average distance between the plants (F and S); completion of the experi- 

 ments of sowing and planting on different types of moors after ditching (F); 

 publication of the investigations on older plantations, carried out by use of 

 planting spit (F). 



New investigations. 



Ascertainment of the most suitable time for sowing and planting, combined 

 with meteorological observations (on the research domains) (S); cultivation 

 experiments on soil disposed for freezing, on the research domain of Svart- 

 berget (S); cultivation experiments on meagre heaths in Småland (N); cultiva- 

 tion experiments on the drained moors of the research domains (S). 



2. The Development of Forest Stånds. 



a) Productive yield of the forests and of forest stånds. 



Continued investigations. 



Studies on the trunk form; yield tables for pine, spruce, birch and oak 

 (S); studies of the length of the growing period of the common forest trees (N). 



New investigations. 



Collection of material for the study of the constitutional structure and pro- 

 duction of the selection type of forest, combined with observations of the 

 regeneration obtained with different selection methods (S). 



b) Measures for the care of stånds. 



Continued investigations. 



Rearrangement of the material concerning different methods of thinning, 

 new experiments with extra heavy thinnings, on the research domains and 

 on suitable places in the western parts of upper Norrland (S); studies on the 

 changement of the covering of the ground according to different systems of 

 thinning (N and S). 



New investigations. 



The problem of thinning treated from physiological point of wiew (N and 

 S); figures showing the relative value of different dimensions, in order to 

 ascertain the economical effect of different methods of thinning (S). 





