Current issue: 51(2)

Under compilation: 51(3)

Impact factor 1.470
5-year impact factor 1.788
Silva Fennica 1926-1997
Acta Forestalia Fennica

Silva Fennica 1926-1997 no. 4 | 1927

Category: Article

article id 4445, category Article
Aimo Kaarlo Cajander. (1927). The scientific foundation of forestry as exemplified by Forest Research Work in Suomi. Silva Fennica no. 4 article id 4445.

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, ORCID ID:E-mail:
article id 4444, category Article
Toivo Wilhelm Paavonen. (1927). Forest fire insurance in Suomi. Silva Fennica no. 4 article id 4444.

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 have similar conditions, rates and principles for estimating losses.

2,18 billion hectares (16,4%) of the 13.3 billion 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 are classified either small forest (less than 18 cm in diameter), large forest or forest in general. The basic insurance compensates the stump value of the timber felled and lying in the forest up to 25% of the volume in the area, and the forest soil up to 50% of the value of the land (in case the fire decreases productivity of the land). Larger losses can be compensated by paying an additional premium.

A summary in Finnish is included in the PDF.

  • Paavonen, ORCID ID:E-mail:
article id 4443, category Article
Oskari Jalmari Lukkala. (1927). What points of view have to be taken into consideration, when draining swamp lands for afforestation. Silva Fennica no. 4 article id 4443.

Draining of peatlands requires careful planning because of its costs. Only peatlands, which will have satisfactory growth capacity after draining should be chosen. The future growth capacity can be estimated with help of peatland type, the botanical composition of the peat layers and the quality of the surface peat layer of the swamp.

Also the 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 drained peatlands in Finland have been covered with forest. Especially the young trees regain soon their growth. It is recommended to leave the young trees, but most profitable to harvest the older part of the forest. According to practical experience, also the drained open peatlands are inclined to afforestation. The natural regeneration is almost guaranteed on peatlands, where there are growing seed trees.

A summary in Finnish is included in the PDF.

  • Lukkala, ORCID ID:E-mail:
article id 4442, category Article
Lauri Ilvessalo. (1927). Cultivation of foreign species of trees. Silva Fennica no. 4 article id 4442.

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. Seed should be procured from a part of the area of distribution, where the climate is most similar to the climate in the area of cultivation. In addition, the site requirements should be met. To be worth of cultivation, the foreign tree species should offer advantages over the ingenious 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 European and Siberian larch, Larix sibirica and L. europaea, which both yield more produce than the indigenous species and have better durability against rotting. In Central Europe, Douglas fir, White pine and Sitka spruce have proved to be good forest trees. In Hungary Robinia has become economically important. Eucalyptus has been cultivated in Mediterranean countries, South America and California.

A summary in Finnish is included in the PDF.

  • Ilvessalo, ORCID ID:E-mail:
article id 4441, category Article
Yrjö Ilvessalo. (1927). Preparation of growth and yield tables. Silva Fennica no. 4 article id 4441.

One of the most difficult tasks in constructing growth and yield tables has been to determine which of the sample plots of the same tree species belong, with respect to the site quality class and to the quality of the stand, to 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 common defects. There were two main differences to the earlier work. Firstly, on each sample plot the site quality class was determined when the sample plot was taken, independently of the stand occupying the site. Thus 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. Secondly, when studying which of the sample plots of the same quality class belong to the same growth series, mathematic-statistical methods were used to deduct the so-called stem frequency distribution 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.

A summary in Finnish is included in the PDF.

  • Ilvessalo, ORCID ID:E-mail:
article id 4440, category Article
Yrjö Ilvessalo. (1927). The inventory of forest resources. Silva Fennica no. 4 article id 4440.
  • Ilvessalo, ORCID ID:E-mail:
article id 4439, category Article
Aimo Kaarlo Cajander. (1927). Some aspects of forest research work. Silva Fennica no. 4 article id 4439.
  • Cajander, ORCID ID:E-mail:
article id 4438, category Article
Aimo Kaarlo Cajander. (1927). Teaching of forestry in Suomi, general features. Silva Fennica no. 4 article id 4438.
  • Cajander, ORCID ID:E-mail:
article id 4437, category Article
Aimo Kaarlo Cajander. (1927). The organization of forest administration in Suomi. Silva Fennica no. 4 article id 4437.
  • Cajander, ORCID ID:E-mail:

Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content

Your selected articles