Silva Fennica no. 4 | 1927

The article is a lecture given by A.K. Cajander in the International Congress of Plant Science. The lecture describes results of Finnish forest research that might be regarded significant also for North America. Because of similarities in nature and forest management, forest research may use similar methods in both areas.

For instance, line plot survey in the form used in Finland could well be applied in North America. In Finland, lines were drawn at 26 kilometer intervals. Visual estimates about, for instance, species, tree growth and productivity class, were made along the lines and sample plots were taken every other kilometer. To gain full advantage of the method, a productivity classification and yield tables are needed. When these are known, it is possible to find out how to increase the productivity of forests with suitable tree species and proper forest management. This kind of inventory of forest resources and the state of forests provides reliable information for forest policy. Another important issue for forest research is forest management, which requires understanding on their biology. At the same time, research must provide methods for practical forestry.

A summary in Finnish is included in the PDF.

• Cajander, E-mail: ac@mm.unknown

Establishing an insurance company for insuring the private forests was suggested already in 1911 in Finland. In 1925 two companies, the Suomen Metsänomistajain Keskinäinen Metsäpaloapuyhdistys (The Forest Owners' Mutual Forest Fire Insurance Company) and the Keskinäinen Vakuutuslaitos Sampo (The Sampo Mutual Insurance Company), operated in forest fire insurance. They both had similar conditions, rates and principles for estimating losses caused by forest fire.

A total of 2,18 million hectares (16,4%) of the 13.3 million hectares of private forests in Finland were insured in 1925. Of the insured forests, 0.01–1.35% burned annually in 1916–1925. The insured forests were classified either small forests (size of the trees less than 18 cm in diameter), large forests or forests in general. The basic insurance compensated the stump value of the timber felled and lying in the forest up to 25% of the volume in the area. In case the fire decreases productivity of the land, the insurance covered the forest soil up to 50% of the value of the land. Larger losses could be compensated by paying an additional premium.

A summary in Finnish is included in the PDF.

• Paavonen, E-mail: tp@mm.unknown

Draining of peatlands requires careful planning because of its costs. Only peatlands that have sufficient growth capacity in future should be drained. The future growth capacity can be estimated based on peatland type, the botanical composition of the peat layers and the quality of the surface peat layer of the swamp.

Also the draining methods should be cost effective. To keep the amount of drains low, the drain network and drain lines should be planned so that each drain has high drain effectivity. Most of the peatlands drained in Finland have been forested. Especially the young trees regain soon their growth when the peat begins to dry. It is recommended to leave the young trees, but most profitable to harvest the older forests in the drained area. Practical experiences have shown that even drained open peatlands can be naturally regenerated. Natural regeneration is almost guaranteed to succeed on peatlands, which have seed trees.

A summary in Finnish is included in the PDF.

• Lukkala, E-mail: ol@mm.unknown

Successful cultivation of a tree species outside its natural area of distribution involves that the original climate is similar to that of the area where it will be cultivated. Seeds should be procured from an area, where the climate is most similar to the area of cultivation. In addition, the site requirements should be met. To be worth of cultivation, the exotic tree species should offer advantages over the native species, such as wood quality, higher productivity, modest site requirement, greater endurance against spring frosts and cold in the winter, valuable by-products, resistance against grazing, insects or fungi, or improvement of soil.

In Finland, successful examples are Larix europaea Lam. & A. DC. and Larix sibirica Lebed, which both give better yield than the native species, and have better resistance against decay. In Central Europe, Pseudotsuga mentziesii (Mirb.) Fnanko, Pinus strobus L. and Pinus sitchensis (Bong.) Carriére have proved to be good forest trees. In Hungary, Robinia pseudoacacia L. has become economically important. Eucalyptus spp. have been cultivated in the Mediterranean countries, South America and California.

A summary in Finnish is included in the PDF.

• Ilvessalo, E-mail: li@mm.unknown

One of the difficulties in constructing growth and yield tables has been to determine which of the sample plots growing the same tree species and belonging to the same forest site type, with reference to the quality of stands, have to be included in the same growth series.

New growth and yield tables for the most important tree species were constructed in Finland in 1916–1919, using new principles that aim at avoiding some of the common weaknesses. There were two main differences to the earlier work. First, the site quality class (forest site type) was determined for each sample plot when the sample plot was measured, independently of the stand occupying the site. In this way it was possible to treat the sample plots of each site as an independent group from the beginning, and so that the quality classes were the same for all the tree species. Second, mathematic-statistical methods were used to deduct the so-called stem frequency distribution series, when studying which of the sample plots of the same quality class belong to the same growth series. They represent the average number of stems of the different diameter classes. A more detailed description of the method used to create the growth and yield tables is published in Acta Forestalia Fennica no. 15.

In the PDF is included a summary in Finnish.

• Ilvessalo, E-mail: yi@mm.unknown

Line plot survey has proven the best method to assess forest resources in the Northern countries on a country level; it is cost effective and gives reliable results. The accuracy of the survey depends on, however, how close the lines are set. To get homogenous statistics of an entire country, the survey should not span over too long a period. Thus, the distance between the lines should be chosen wide enough to give accurate results quickly for the whole country, while accepting slightly less exact results for its smaller districts.

If line survey is performed on large areas, it is not possible to count and measure trees, measure the tree growth. etc. along the whole length of the line because of its costs. Therefore, more precise measurements are limited to sample plots, which are spaced evenly along the lines. Between the sample plots, the volume and growth of each stand touching the line are estimated visually. These visual estimates have often systematic faultiness, which can be eliminated with correlation calculations. Visual observations gather information, for instance, about land owner, soil type, land-use class, forest site type, tree species and age class of the stand, density, wood volume ja annual growth per hectare, and the current silvicultural state of the stand. With help of this kind of information it is possible to get sufficient statistics about the forest resources of a country.

A summary in Finnish is included in the PDF.

• Ilvessalo, E-mail: yi@mm.unknown

The article highlights the need to classify the forest sites in objective and exact classes. This is important both from a practical and a scientific point of view as well as from a silvicultural point of view, for the forest management varíes for each tree species, and according to the site, even if the species remains the same. It is evident that the same classification of sites according to quality ought to be applicable to silviculture, forest mensuration and statistics. In Finland, a forest site type rating has been created for this purpose.

The PDF includes a summary in Finnish.

• Cajander, E-mail: ac@mm.unknown

The higher education of forestry in Finland was transferred to the University of Helsinki in 1908 from the Evo Forest Institute, where it was established in 1859. The principal idea was that the University should educate practical forest officials with a scientific education, and that the more talented students should be able to continue their scientific studies. The four main diciplines were silviculture, forest management, forest utilization and forest policy. The studies for the forest officer examination took about 3–4 years. For those students interested in further scientific studies, a Candidate (Master) and Licentiate (Doctor) examination was arranged.

In addition to higher education, elementary forestry education was arranged at five Forest Schools in different parts of the country.

The PDF includes a summary in Finnish.

• Cajander, E-mail: ac@mm.unknown

A temporary organization for forest service was established in 1851 for the State forests of Finland. It was made permanent in 1859, and a central board, chief forest supervisors, forest supervisors and forest guards were appointed for the state forests. The Forest Research Institute, established in 1917, was subordinated to the Board of Forestry. In addition, the higher forest education was subordinated to Board of Forestry until it was moved to the University of Helsinki in 1908.

In 1921 the administration was reorganized to meet the requirements of developing forestry in the state forests. The Forest Service was divided into two sections: The State Forest Section and the Private Forest Section. The first consists of four divisions and the latter two. The forests under the supervision of the State Forest Section are divided into four districts, and each of these into two or three inspection territories. Under the supervision of the Private Forest Section are the forest schools, the Forest Research Institute, and the forest officials working for the ecclesiastical forests and Provincial Forest Committees. The Forest Research Institute is only nominally subordinated to the Private Forest Section of the Board of Forestry. It has 17 experimental areas in various parts of the country. These areas have been separated from the supervisor-areas of the state forests.

The PDF includes a summary in Finnish.

• Cajander, E-mail: ac@mm.unknown