C—3a

This Division is concerned primarily with the main problems of silviculture. The Division is thus to lay down the main principles along which forests should be managed, including the problems of thinning during the growing period, when and how they should be finally cut, and how reproduction—natural or artificial —is to be ensured. These problems require research within two extensive fields of investigation : yield studies and reproduction studies. Forest mensuration aims at establishing the methods of computing the volume of individual trees and stands, the distribution of timber into different assortments and forest increment. 155. Forest Survey Division.—The main object of the Division for Forest Survey is to ascertain by continuous nation-wide surveys the state and condition of the forest resources and also changes occurring in them (national forest survey), and further to compute the annual cut. 156. Science of Work Division. —The main task of the Division will be to carry out research for further simplification and improvement of different forest operations, above all logging and transportation—i.e., work operations intimately connected with the economic carrying capacity of forestry and the standard of forest workers. 157. Botany and Soils Division.—Research within this division is concentrated around problems of geobotany, soil biology, mycology, plant physiology, and their related problems. Within the geobotanical field, investigations are made on plant associations (forest types), and especially on their connections with the nature of the soil. Biological research aims at throwing light on the biological processes taking place in the soil which are of importance to forestry. Mycological research is done on the fungus diseases of living trees, as well as on destructive fungi and their damage to wood products. Of importance in this connection is to find out means and methods to counteract the damage done by these fungi. Physiological research on plants is carried out in connection with the problem indicated above. The chief object of this Division is to extend out knowledge of the scientific possibilities of forest production. Thus the work is concentrated on investigating the often very complex processes going on in tree and soil. The results won through this basic research will serve as important starting-points in solving the numerous practical secondary problems mainly dealt with in the Forestry Division. 158. Genetics Division.—Research in this Division aims at solving problems connected with forest tree breeding, chiefly by selection. For this purpose work is done on the resistance of young trees to the attacks of parasitic fungi and injurious insects {resistance research). Test work is also carried out with regard to the importance of the geographical provenance of the seed (provenance research). 159. Zoology Division. —The Zoological Division aims at investigating the biology of the injurious insects attacking trees and timber, and to indicate suitable means for counteracting their damage. Attention is also given to the soil fauna and to its significance for the soil processes. 160. Mathematical Statistics Division. —The methods of mathematical statistics, especially regression analysis and analysis of variance, have proved almost indispensable in advanced forestry research. To meet the requirements of statistical analysis of data collected by the various divisions of the Institute, a special section of mathematical statistics has been established. In addition to standard calculating-machines, the section will have at its disposal the Institute's punched-card machines. 161. It can be seen from this survey that the separate Divisions, by their collaboration, form one big research unit. The increased knowledge of the biological processes active in the life and development of Swedish forests obtained through the scientific

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