Silva Fennica vol. 4 no. 2 | 1970

This paper is a book review of the book Grundzüge der Waldhygiene by Erwin Schmitschek.

• Nuorteva, E-mail: mn@mm.unknown

The most effective work organization will be used as a goal in minimizing of logging costs. Some type of problem approach is usually utilized. The concept of the ideal system offers a possibility to get guidance in this difficult task. The idea of an ideal system is based on the fact that an ideal system, even imagined, can be utilized for any purpose. There are checklists in handbooks to accomplish the four existing steps: define of function, design ideal, develop optimum and deliver results.

In this paper two special cases are taken up to illustrate the concept itself, and it’s use in design of forestry work organizations. There were found no such reasons which could limit or even prevent the use of this method for forest technological purposes. That is why the author believes the method to give better results than any other customary approach.

The PDF includes a summary in English.

• Haarlaa, E-mail: rh@mm.unknown

The purpose of this study was to explain whether it is possible to affect, in practical working site conditions, by means of logging waste on the strip road, the depth of the track which is formed in terrain transportation and the injuries of the growing stand. Five 20 m long investigation areas with logging waste and five similar areas without logging waste were arranged on one strip road at Teisko logging site in Southern Finland. The logging waste layer was mainly Norway spruce and 10–15 cm thick. A KL–836 B forwarder was used. The type of soil was loam.

The logging waste affected the depth of the track only by decreasing the wear of humus layer. Even decreasing effect of logging waste on the injuries in the growing stand was minor. At Kitee working site in Eastern Finland strip roads were studied. The type of soil was thick, rather mouldered peat. The thickness of logging waste was 3–4 times greater than in Teisko, mainly spruce. A Volvo Nalle SM 460 forwarder was used. The effect of the logging waste on the depth of the tracks was clearly to be noticed. On basis of the appearance of the tracks one could assume that the difference was due to different wear of the humus, and not so much due to the quantity of logging waste that improves the carrying capacity of terrain.

In some extent logging waste was also found to affect the amount and quality of tree injuries. In practical working conditions, the importance might be small, since in the experiments an unrealistically great amount of logging waste was used.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

This investigation studies the effect of the retail price and the technical properties of preference ordering of buyers of power saw. According to the model derived, the preference ordering of power saws is due to technical properties x_j. If no such restrictions in the function are supposed that could have bearing on the preferences of the buyers, there may be N ! possible combinations, when there are N power saws. If one can presume that each price corresponds with a technical level it is possible that each buyer has an optimum price of his own. The bigger the difference between the optimum and actual price, the less preferred the actual power saw is. In this case one may notice the amount of possible orderings is much less than that based on the model. Thus, the mode may be used.

In this paper some models are presented for cases when only n pieces of the population of N power saws are studied. 16 power saws of differing ages and technical levels were investigated. It was noted that many criteria of technical goodness were positively intercorrelated. The price correlated positively with every criterium used. According to the profile analysis, it was concluded that there were many development lines. For example, the idea of a light and the idea of an effective power saw.

According to the principal component analysis, it seemed obvious that there was little room for one- or two-dimensional preference ordering by the technical properties and price.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

This paper presents the results of a contest performed on behalf of the Finnish bank Kansallis-Osake-Pankki and the Central Forestry Board Tapio on growing trees on peatlands. Over 5,000 sample plots were established on drained peatlands in various parts of Finland. The aim was to achieve a best possible growth of seedling stands on peatland. The factors influencing the growth of 85 best Scots pine (Pinus sylvestris L.) and 60 best Norway spruce (Picea abies (L.) H.Karst.) sample plots were studied.

The height growth of the seedling stands decreased towards the north. Fertilization seemed not to decrease the regional differences; rather on the contrary. On the other hand, fertilization increased height growth, but evidently so that the increase obtained was greater in the southern than in the northern parts of the country. Light fertilization (50 kg/ha of K₂O and 60 kg/ha of O₂P₅) caused a clear increase in height growth while heavy fertilization (100 g/ha of K₂O and 120 kg/ha of O₂P₅), had same effect but to much greater extent than the former. Spruce seedling stands in particular benefitted of the heavy fertilization.

Fertilization did not eliminate the original differences in the quality of the sites in question, but these could still be seen in the height growth after fertilization. The effect of drain spacing on the height growth was not very clear. In dense seedling stands (800 seedlings/ha) the height growth of the dominant seedlings was greater than that obtained in stands of lower density. Hold-overs caused a decrease in the growth of the seedling stands.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown
• Ouni, E-mail: jo@mm.unknown

An attempt was made to estimate critically the genetic gain in clonal seed orchards of Scots pine (Pinus sylvestris L.) in Finland. The selection differential of Scots pine and Norway spruce (Picea abies (L.) H. Karst.) is calculated on the basis of filed information on selected plus trees which has been kept by the genetic register at the Finnish Forest Research Institute. The differentials were computed as realized differences in height between plus-trees and normal stand characteristics on respectively site class and as a function of age.

The genetic gain in height growth of Pinus sylvestris was computed on the basis of information on selection differential and heritability. This genetic gain is between 2.6–4.4% provided there is no pollen contamination from unknown sources outside the seed orchard. The genetic gain of volume growth in Scots pine is about 7–15%, provided there is no pollen contamination in the seed orchard. However, according to investigations, there is invariably some pollen contamination in this kind of seed orchards. The contamination decreases to about 30–50% as the orchard matures and starts to produce endemic pollen. If the pollination would be entirely due to foreign pollen sources, the mathematically calculated genetic gain would be 3.5–7.5%.

The PDF includes a summary in English.

• Tigerstedt, E-mail: pt@mm.unknown
• Malmivaara, E-mail: em@mm.unknown