Current issue: 55(4)
Under compilation: 55(5)
The forestry working group of the committee for scientific and technical cooperation between Finland and the Soviet Union initiated cooperation work between the two countries in the field of forestry almost ten years ago. The Finnish organizations the Department of Peatland Forestry, the Finnish Forestry Research Institute, and the Institute of Peatland Forestry of the University of Helsinki participated in the activity. From the Soviet Union the participants have been the Ministry of Forestry, the Russian Federation of USSR, and the Forestry Research Institutes of Leningrad and Estonia.
This paper includes the papers presented in the joint symposium arranged at the Forest Field Station of University of Helsinki on 17.9.1979. The 9 Russian lectures and the 8 Finnish ones, are presented either in their entirety or slightly condensed variably in Finnish, English or Russian. The summary of the seminar is presented in English and in Russian.
The present paper is a preliminary report of a project designed to determine the order of profitability of various forest improvement measures – seeding and planting, drainage, and fertilization – in various types of stands and in different parts of the country on drained peatlands. Sample plot data on the effect of draining on increment was derived from areas drained 28– 36 years ago. The study was carried out in the southern half of Finland.
The observations on increment changes are based on two measurements of the sample stands 12 years apart. Supplementary calculations indicate that the stands on drained peatland, depending on site quality and tree species, have either continued to grow like mineral-soil sites of similar fertility or have somewhat increased their growth rate.
The effect of draining intensity was studied using strip measurements. It was found that both the total amount of wood produced (current stand + cutting removal + natural removal) and the current annual volume increment for the 5-year period systematically decrease as the ditch interval increases. The decrease is, however, relatively slight. In Eriophorum vaginatum pine swamps, the total amount of wood produced and the increment show a decrease of ca. 20% with an increase in ditch interval from 20 to 60 metres. In other sites, the decrease is ca. 5-10%
It can be concluded that if the increase in ditch interval do not result in considerably poorer timber assortment distributions than indicates by stand production and increment, it is profitable to pan for a relatively large ditch interval and a slightly smaller than maximum wood production. Supplementary data and check calculations may cause some changes in these preliminary results.
The PDF includes a summary in English.
About one third of the land area of Finland is covered by peatlands, furthermore, some mineral soils are troubled by excess water. Due to the prevalence of peatlands, forest drainage has been the most important form of forest improvement work. Consequently, peatlands have been an extensively studied topic within forest sciences in Finland. This paper gives a review on the central research subjects in science of peatlands, introducing little less than a hundred of the hundreds of publications published in the field. The author describes in more detail research on the formation and area of peatlands, peatland types and their suitability for forest draining, site factors on peatlands, techniques of forest ditching and the management of peatland forests.
The PDF includes a summary in Finnish.
Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.
This presentation describes the factors that limit growth of trees in peatlands, and principles of draining of peatlands.