Articles by Mikko Ilvessalo

In the 1930s studies showed that state of the standing crop and forests of small private forest holdings in Finland was weak. In 1960s it was regarded necessary to study the possible change in the silvicultural state of these forests. Therefore, sample stands of the small holdings surveyed in 1930 by Osara were surveyed anew in the areas of Karelia and Savo, and in Central Finland in 1963–1964. A line plot survey was combined with ocular estimation as in 1930, but in 1963–1964 the lines and sample plots were placed denser than in 1930 to reach similar number of sample plots.

In 1930 the state of the forests of the small holdings was in average very weak, but according to Osara, the age classes younger than 50 years had similar stand volume than in the all the forests of the southern half of the country. The results of this survey show that the volume, structure, growth and development class structure of the forests in average have improved since 1930. In many respects the forests have reached the average state of forests in the southern half of Finland. The most serious problem is the large proportion of broadleaved trees. Thus, the silvicultural state of the forests should be further improved.

The PDF includes a summary in German.

• Ilvessalo, E-mail: mi@mm.unknown
• Ilvessalo, E-mail: yi@mm.unknown

The aim of the present study was to describe the forest types of Finnish mineral forest lands as a uniform whole in the light of stand development and wood production.

The study shows that it has been possible to work out uniform age-based development series for different stand characteristics for forest types on mineral forest lands in Finland. There is generally a clear difference in the development series of various stand characteristics and their average values between different forest types. The exceptions in a few places have been explained as depending on certain factors. The differences between adjacent forest types in order of their quality are of varying magnitude, thus differing from a schematic site quality classification obtained through calculation. Consequently, each forest type has its own development series with regard to the stand characteristics.

The number of forest types in the whole country is rather high. However, the different forest types are limited to different parts cf the country in such a way that there is no need for more than 5–6 forest types and 4 northerly sub-forms (-types) in each region, except in the border areas between the regions. In Finland the forest types have been the basis of forest site classification in forest research and practical forestry over a period of half a century. In pointing out the necessity of further study of forest types, Cajander has stressed the examination of differences in the compositions of vegetation between different classes of density of tree-stand and building up average descriptions of vegetation in such classes in young, middle-age and old stands. The same may be caused by some other factors which also are of essential influence to the composition of the vegetation.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@mm.unknown
• Ilvessalo, E-mail: mi@mm.unknown