XVI I'R0(;R.\.M OV IHK SWKDISH INSIHU IK ok KXrKKl.MKXTAL KORF.SIKV. 



2. Proceedings as regards the Composition of Forests. 



(a) Sligli/ and extenstve ihinning operations. Existing areas for slight and extensive 

 thinning shall be revised if necessary,and new areas shall be arranged,so far as time 

 ])ermits, chiefly in pine forests and spruce forests of low i)roductivity, and in spruce 

 forests in Norrland of all grades of productivity, in the birch forests of Norr- 

 land, in certain forests composed of aspen and oak, and in mixed coniferous 

 forests (S.). In the last-named mixed forests there shall be arranged areas 

 of young seedlands or plantations in order to throw light upon the best way 

 of raising forests of mixed composition (S.). 



(b) Ålteration of gronnd-flora. In some of the more suitable experimental areas 

 for heavy thinning the ground vegetation shall be investigated in accordance 

 with the Raunkiaer method, as modified by Lagerberg, in order to obtain 

 fixed points for estimating the effect of the most thorough thinning upon the 

 ground-vegetation (N.). 



3. Diseases and Injuries of Forest trees. 



{(i) Diseases and injuries cansed by fungi. The occurrence and spread of 

 the roots in the spruces whose tops were broken off during the winter of 

 1 91 o — II shall be examined (N.). Moreover the roots of coniferous trees 

 shall be taken up for closer investigation, with special attention to the con- 

 ditions in the over-aged forests in Norrland (N.). 



{b) Injuries cansed by insects. Investigations shall be instituted as regards 

 injurious insects both in spruce-cones and pine-cones and in forests-plants in 

 nurseries. The extent of the increased ravages of bark-beetles in certain 

 districts shall be studied; and at the same time knowledge of the known 

 methods of efifectively dealing with these last-named insects should be spread 

 amongst forests-owners. In addition to this, should other insect ravages take 

 place, studies should be instituted and advice given as to the checking of 

 their ravages (K.). 



4. Races of Forest trees and the Serviceableness of Foreign Forest 



trees Sweden. 



{(i) Race-studies of spruce and pine. Previous plantations of plants raised 

 from selected seed shall be looked after so far as is necessary (N.). 



(({') German spruce-seed. Existing stocks of plants of German spruce shall 

 be used for the laying-out of experimental areas, and the stock of plants 

 shall be handed över to the superintendent of forest-di stricts (»revirs») with 

 the request that they may be used in the forest-cultures of the district (S.). 



(c) Larch. Further areas shall be laid out in larches, after which the re- 

 sults of the investigation into this kind of tree shall be prepared for publi- 

 ( ation (S.). 



5. Investigations concerning Forest Land. 



{a) Types of Soil. With a view to cffecting a systematic survey of the 

 different types of forest land in Sweden an investigation of the most impor- 

 tant types shall be begun, in which attention shall be directed both to the genesis 

 of the types and to their value from the standpoint of forestal productivity (N.). 



