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Impact factor 1.683
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Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Silva Fennica 1926-1997 vol. 23 | 1989

Category: Article

article id 5396, category Article
Matti Leikola. (1989). Uuteen maatalous- ja metsäakatemiaan. Silva Fennica vol. 23 no. 4 article id 5396. https://doi.org/10.14214/sf.a15554
English title: Towards new agriculture and forest academy .

This paper is a commentary which summarises the history of the Finnish Society of Forest Science and its connection to the corresponding society in the field of agriculture, the Scientific Agricultural Society of Finland. The original idea when the Scientific Agricultural Society of Finland was founded was that the society would function as a scientific society for both forest scientists and agronomists. However, A.K. Cajander founded a separate academy for forest sciences. The article discusses the implications of this decision. 

  • Leikola, ORCID ID:E-mail:
article id 5395, category Article
Mirja Kortesharju, Jouko Kortesharju. (1989). Studies on epiphytic lichens and pine bark in the vicinity of a cement works in northern Finland. Silva Fennica vol. 23 no. 4 article id 5395. https://doi.org/10.14214/sf.a15553

The element content (Ca, Mg, K, Na, Fe, Mn, Zn, Cu, Pb, S) of Scots pine (Pinus sylvestris L.) bark and Bryoria lichens, as well as the occurrence and coverage of epiphytic lichens and the length of Bryoria species, were studied in the vicinity of Kolari cement works, NW Finland. Fruticose Bryoria species had the highest coverage on pine trunks at a distance of 2 km or more from the cement works. At a distance of 1 km the foliose – or even crustose – Parmeliopsis species were most abundant, while nearer to the works lichens were almost completely absent. The length of Bryoria was reduced at distances of less than 2 km from the cement works. The calcium content in Bryoria species increased very steeply close to the works; by a factor of 60 at a distance of 1 km compared to 16 km. No corresponding increase in other elements was observed near the cement works. All the elements studied in pine bark showed a significant negative correlation with distance, and a significant positive correlation with the calculated dust deposition levels. There were only minor differences between the north and south of the pine trunks, or the side facing or away from the works. Pine bark analysis is recommended for element accumulation studies.

The PDF includes an abstract in English.

  • Kortesharju, ORCID ID:E-mail:
  • Kortesharju, ORCID ID:E-mail:
article id 5394, category Article
Pekka Kilkki. (1989). Kestävä metsätalous. Silva Fennica vol. 23 no. 4 article id 5394. https://doi.org/10.14214/sf.a15552
English title: Sustainable forest management.

This paper is a review on the development of sustainable forest management and what has been meant with the term in different times. The article summarises the birth of sustainable use of forests in the world and in Finland, and discusses sustainability in forest management, for instance from the point of view of one forest holding, large clearcuttings performed in Lapland, biological sustainability, business economics and overall planning.

  • Kilkki, ORCID ID:E-mail:
article id 5393, category Article
Erkki Annila. (1989). Metsien kunto ja bioottiset tuhonaiheuttajat. Silva Fennica vol. 23 no. 4 article id 5393. https://doi.org/10.14214/sf.a15551
English title: Condition of forests and biotic damages .

This review discusses whether forests are affected by biotic damages due to present or future environmental disturbances, and do environmental threats, such as air pollution and climatic change, weaken the condition of forest in a way that makes them vulnerable to damages by fungi and insect. The defence mechanisms of trees and factors affecting the development of an outbreak are described. Finally, the ways that air pollution and climatic change may affect biotic damages are discussed. 

  • Annila, ORCID ID:E-mail:
article id 5392, category Article
Pekka Kilkki, Matti Maltamo, Reijo Mykkänen, Risto Päivinen. (1989). Use of the Weibull function in estimating the basal area dbh-distribution. Silva Fennica vol. 23 no. 4 article id 5392. https://doi.org/10.14214/sf.a15550

The paper continues an earlier study by Kilkki and Päivinen concerning the use of the Weibull function in modelling the diameter distribution. The data consists of spruces (Picea abies (L.) H. Karst.) measured on angle count sample points of the National Forest Inventory of Finland. First, maximum likelihood estimation method was used to derive the Weibull parameters. Then, regression models to predict the values of these parameters with stand characteristics were calculated. Several methods to describe the Weibull function by a tree sample were tested. It is more efficient to sample the trees at equal frequency intervals than at equal diameter intervals. It also pays to take separate samples for pulpwood and saw timber.

The PDF includes an abstract in Finnish.

  • Kilkki, ORCID ID:E-mail:
  • Maltamo, ORCID ID:E-mail:
  • Mykkänen, ORCID ID:E-mail:
  • Päivinen, ORCID ID:E-mail:
article id 5391, category Article
Jukka Pietilä. (1989). Shape of Scots pine knots close to the stem pith. Silva Fennica vol. 23 no. 4 article id 5391. https://doi.org/10.14214/sf.a15549

The shape of Scots pine (Pinus sylvestris L.) knots close to the pith of butt logs was investigated. 1,100 knots were split in a vertical direction, and their shape was measured. Knot diameter and branch angle were calculated at a distance of 40 mm from the pith of the stem. The mean diameter of all the knots in the material was 14 mm, and the branch angle 70°. Regression analysis was used to devise a formula for predicting branch angle on the basis of knot diameter. Knot size and branch angle were negatively correlated. Especially the shape of larger knots was curved. Knots achieved their maximum diameter at distance of 4–5 cm from the stem pith. The branch wood was almost completely situated above the formation point of the branch.

The PDF includes an abstract in Finnish.

  • Pietilä, ORCID ID:E-mail:
article id 5390, category Article
Kari Heliövaara, Kari Löyttyniemi. (1989). Effect of forest fertilization on pine needle-feeding Coleoptera. Silva Fennica vol. 23 no. 4 article id 5390. https://doi.org/10.14214/sf.a15548

The effects of forest fertilizers on the intensity of damage caused by two curculionid (Brachyderes incanus L., Brachonyx pineti Paykull) and two chrysomelid (Calomicrus pinicola Duft., Cryptocephalus pini L.) species feeding as adults on Scots pine (Pinus sylvestris L.) needles were investigated in two pine stands growing on dry (Calluna type) sites in South-West Finland. There was much variation in the abundance of the insect species both between the trials and the sample plots. Nitrogen fertilization increased both the height and radial growth of the pines. The curculinids were slightly more abundant on the nitrogen-treated plots. Potassium application seemed to decrease the feeding intensity of the chrysomelids especially. The overall effects were so small that forest fertilization cannot be considered as an effective control method against needle-feeding beetles.

The PDF includes an abstract in Finnish.

  • Heliövaara, ORCID ID:E-mail:
  • Löyttyniemi, ORCID ID:E-mail:
article id 5389, category Article
Jyrki Tomminen, Matti Nuorteva, Markku Pulkkinen, Jouni Väkevä. (1989). Occurrence of the nematode Bursaphelenchus mucronatus Mamiya & Enda 1979 (Nematoda: Aphelenchoididae) in Finland. Silva Fennica vol. 23 no. 4 article id 5389. https://doi.org/10.14214/sf.a15547

A survey was conducted in Finland in 1988 to determine whether the pine wood nematode Bursaphelenchus mucronatus Mamiya & Enda 1979 (Nematoda: Aphelenchoididae) or the closely related species B. mucronatus would occur in Finnish forests. Dead or dying standing trees and timber of two conicer species, Pinus sylvestris L. (Scots pine) and Picea abies (L.) H. Karst. (Norway spruce) were analysed for the presence of these nematodes. Monochamus spp. pine sawyers (Coleoptera: Cerambycidae) were also collected and inspected for the presence of dispersal fourth juvenile stages (dauerlarva) of the nematodes. The species B. xylophilus was not found, but B. mucronatus appeared to be widespread in the country. Individuals of this nematode were found both from Scots pine and Norway spruce. Adults of two Monochamus species were found, M. galloprovincialis and M. sutor. Only two of the examined beetles of the former species had dauerlarvae in their body.

The PDF includes an abstract in Finnish.

  • Tomminen, ORCID ID:E-mail:
  • Nuorteva, ORCID ID:E-mail:
  • Pulkkinen, ORCID ID:E-mail:
  • Väkevä, ORCID ID:E-mail:
article id 5388, category Article
Martti Varmola. (1989). Männyn istutustaimikoiden lustonleveysmalli. Silva Fennica vol. 23 no. 4 article id 5388. https://doi.org/10.14214/sf.a15546
English title: A model for ring width of planted Scots pine.

Ring width at breast height is presented as a function of stem radius at breast height, the ratio between the diameter of a tree and the basal area median diameter, site index, and density of stand. By means of a conversion model ring width at stump height can be estimated as a function of ring width at breast height.

According to previous studies substantially better wood quality can be expected if mean width near the pith at stump height decreases from 3 to 2 mm. According to the present study only on the poorest sites suitable for Scots pine (Pinus sylvestris L.) planting (poor Vaccinium type) the ring width is less than 3 mm at stump height even in the thickest trees. On more fertile sites a substantial increase in the recommended planting density is required, if the mean ring width is aimed to be less than 3 mm. On the best sites it is impossible to reach mean ring width of less than 2 mm, when the density is less than 4,000 stems/ha. Only the thinnest trees on the poorest sites can have a mean ring width less than 2mm.

The PDF includes an abstract in English.

  • Varmola, ORCID ID:E-mail:
article id 5387, category Article
Olli Saastamoinen, Seppo Lohiniva. (1989). Picking of wild berries and edible mushrooms in the Rovaniemi region of Finnish Lapland. Silva Fennica vol. 23 no. 3 article id 5387. https://doi.org/10.14214/sf.a15545

According to 459 and 350 questionnaires sent in 1983 and in 1985, respectively, the households in the Rovaniemi region located in the Arctic Circle in Northern Finland, eagerly picked wild berries. In both years, four out of five households picked at least one species of berry. In 1983 the total amount of wild berries picked was 29.2 kg per capita. In 1985 it was 15.0 kg per capita. Three species, the lingonberry (Vaccinium vitis-idaea L.), cloudberry (Rubus chamaemorus L.) and bilberry (Vaccinium myrtillus L.) made up 96% of all the wild berries picked during both years. Most of these berries were picked for the family’s own use, but many were also picked for sale. In 1983, 43% of all berries picked were sold, in 1985, 19% were sold. The cloudberry, although difficult to find, is the most important commercial species and also for household use it is the most sought after wild berry. Only very small amounts of edible mushrooms were collected, 1.0 kg per capita in 1983 and 1.3 kg in 1985.

The PDF includes an abstract in Finnish.

  • Saastamoinen, ORCID ID:E-mail:
  • Lohiniva, ORCID ID:E-mail:
article id 5386, category Article
Risto Päivinen, Hannu Yli-Kojola. (1989). Permanent sample plots in large-area forest inventory. Silva Fennica vol. 23 no. 3 article id 5386. https://doi.org/10.14214/sf.a15544

Theoretical and practical aspects of permanent sample plots are discussed in this paper. A study material of 6,871 permanent sample plots was generated using increment sample plots of the 7th National Forest Inventory of Finland. The effect of measurement errors and use of increment functions as ”a priori” information was studied via simulation experiments. The change in the growing stock volume between two consecutive measurement rounds was divided into the components drain, growth and mortality. Finally, a hypothetical inventory design using permanent sample plots was evaluated.

The PDF includes an abstract in Finnish.

  • Päivinen, ORCID ID:E-mail:
  • Yli-Kojola, ORCID ID:E-mail:
article id 5385, category Article
Timo Kuuluvainen. (1989). Branching dynamics in young Scots pine. Silva Fennica vol. 23 no. 3 article id 5385. https://doi.org/10.14214/sf.a15542

The development of shoot number and shoot properties was examined in successive shoot cohorts of young widely-spaced Scots pine trees (Pinus sylvestris L.) growing in a progeny trial. This was accomplished by reconstructing the branching process of the trees over a period of five years, from tree age 4 to 8. During this time the number of shoots in successive shoot cohorts increased rapidly, while at the same time the mean shoot length decreased. The decrease in shoot lengths from older to younger shoots was accompanied by a decline in the bifuraction frequency of the shoots. In general, rapid changes occurred in the branching characteristics during the yearly development of the trees. The variation in the branching characteristics was reflected in the development of the architecture and biomass production of the trees.

The PDF includes an abstract in Finnish.

  • Kuuluvainen, ORCID ID:E-mail:
article id 5384, category Article
Raija-Liisa Petäistö. (1989). Syyskoulinnan ajankohdan vaikutus männyn taimien kuiva-ainepitoisuuteen, neulasten pitolujuuteen ja juurten uudistumiskykyyn. Silva Fennica vol. 23 no. 3 article id 5384. https://doi.org/10.14214/sf.a15541
English title: The influence of autumn transplanting date on the dry matter content, needle retention values and root regeneration of Scots pine (Pinus sylvestris) seedlings.

The experiment was performed in 1982–85 at the forest tree nursery in Suonenjoki, Central Finland. There were four to five transplanting dates ranging from the beginning of August to the end of September. The dry matter content, root regeneration and needle retention value of Scots pine (Pinus sylvestris L.) seedlings were examined. Development of the needle retention value in autumn was followed in nurseries at Suonenjoki, Rantasalmi, Mäntyharju and Taavetti in 1982.

Root regeneration was usually the worse, the later the seedlings were transplanted in the autumn. The dry matter content was generally lowest in the seedlings transplanted later in the autumn, and also to some extent in the seedlings transplanted at the beginning of August. The needle retention value increased as autumn advanced. Early transplanting in autumn had an adverse effect on the development of needle retention, and the values were highest in the seedlings transplanted later in the autumn.

The PDF includes an abstract English.

  • Petäistö, ORCID ID:E-mail:
article id 5383, category Article
Pasi Miettinen, Aino Smolander. (1989). Growth requirements of Frankia strains isolated from Casuarina equisetifolia, and the influence of the isolates on the growth of the host plant. Silva Fennica vol. 23 no. 3 article id 5383. https://doi.org/10.14214/sf.a15540

Frankia was isolated from the root nodules of Casuarina equisetifolia L. seedlings, grown in a growth chamber, after inoculation with soil originating from an old east Kenyan casuarina forest. Optimum pH for the growth of the two isolates ranged from 6.4 to 6.9. The optimum temperature for their growth was 32°C. The growth of these cultures ceased at NaCl concentration above 2%. The influence of the isolates on the growth of the host plant was determined in a growth chamber experiment in which an American Frankia strain (HFPCc13) was used as a reference. The biomass of the inoculated seedlings was 2.4–4.1 fold those of the non-inoculated control seedlings at the end of the 7-month experiment.

The PDF includes an abstract in Finnish.

  • Miettinen, ORCID ID:E-mail:
  • Smolander, ORCID ID:E-mail:
article id 5382, category Article
Seppo Kellomäki, Taneli Kolström, Hannu Väisänen, Esko Valtonen. (1989). Simulations on the occurrence of dead trees in natural pine stands. Silva Fennica vol. 23 no. 3 article id 5382. https://doi.org/10.14214/sf.a15539

The study aimed at recognizing the phases of forest succession where dead trees most probably occur. The model simulations showed that the increasing occurrence of dead trees culminated after the canopy closure. Thereafter the occurrence of dead trees decreased representing a pattern where high frequency of dead trees was followed by low frequency of dead trees, the intervals between the peaks in the number of dead trees being in Southern Finland about 15–30 years. Around this long-term variation there was a short-term variation, the interval between the peaks in the number of dead trees being 2–4 years. This pattern was associated with the exhausting and release of resources controlled by the growth and death of trees.

The PDF includes an abstract in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Kolström, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
  • Valtonen, ORCID ID:E-mail:
article id 5381, category Article
Jouko Hämäläinen. (1989). Ajatuksia metsän arvon määrittämisestä. Silva Fennica vol. 23 no. 2 article id 5381. https://doi.org/10.14214/sf.a15538
English title: Thoughts about forest valuation.

In this article the methods of forest valuation, especially the sales value tables previously published in Finland are critically examined. In this connection attention is drawn to the rate of interest used in calculating the forest values.

The PDF includes an abstract in English.

  • Hämäläinen, ORCID ID:E-mail:
article id 5380, category Article
Arto Rummukainen. (1989). Moreenimurskeella pinnoitettujen metsäteiden kunnossapito maataloustraktorikalustolla. Silva Fennica vol. 23 no. 2 article id 5380. https://doi.org/10.14214/sf.a15537
English title: Maintenance of crushed moraine paved forest roads with agricultural tractor implements.

The condition of forest road pavements was studied in spring, one week after maintenance and in autumn. The effect of vibrating blade was slightly better than that of pulled drag. Large loose stones couldn’t be pressed into pavement with either of the implements. The use of the vibrating blade was three times as expensive as the use of the pulled drag, however, the blade is suitable for other purposes as well.

The PDF includes an abstract in Finnish.

  • Rummukainen, ORCID ID:E-mail:
article id 5379, category Article
Timo Kuuluvainen, Timo Pukkala. (1989). Effect of Scots pine seed trees on the density of ground vegetation and tree seedlings. Silva Fennica vol. 23 no. 2 article id 5379. https://doi.org/10.14214/sf.a15536

The study uses the methodology of ecological field theory to model the effect of Scots pine (Pinus sylvestris L.) seed trees on the density of tree seedlings and other plants in the field layer. The seed trees had a clear effect on the expected value of the amount and distribution of the ground vegetation. The vicinity of seed trees had an adverse effect on the growth of grasses, herbs and seedlings, while mosses were most abundant near the trees. Models based on the ecological field approach were derived to describe the effect of seed trees on the ground vegetation.

The PDF includes an abstract in Finnish.

  • Kuuluvainen, ORCID ID:E-mail:
  • Pukkala, ORCID ID:E-mail:
article id 5378, category Article
Jukka Pietilä. (1989). Factors affecting the healing-over of pruned Scots pine knots. Silva Fennica vol. 23 no. 2 article id 5378. https://doi.org/10.14214/sf.a15535

The material of the study consisted of 21 Scots pine (Pinus sylvestris L.) trees that had been pruned in the 1930’s and 1940’s. The butt log of the pruned stems was peeled into veneer from which the length and shape of the resin taps were determined. The length of the resin tap was affected in the first place by the knot diameter and the height of the knot along the stem. The length of the resin tap was about 1.5-fold that of the knot diameter. With an increase in the height above the ground of a knot, its length decreases. The resin taps were particularly long on poor sites and in the butt end of the stems, however, the variation in tap length was large both within and between the individual tree stands. The shape of the resin taps is presented in this study by diameter classes. The resin taps studied in the work were longer than those measured in other works. This may be due to the fact that the knots were uncovered by peeling instead of sawing.

The PDF includes an abstract in Finnish.

  • Pietilä, ORCID ID:E-mail:
article id 5377, category Article
Maija Jarva, Arja Tervahauta. (1989). Neulasten rikkianalyysi. Silva Fennica vol. 23 no. 2 article id 5377. https://doi.org/10.14214/sf.a15534
English title: A comparison of sulphur analysis of conifer needle samples.

The results of an intercalibration of sulphur analysis by 24 laboratories are evaluated. The analysis was made by one or more of six methods. The following three methods were found to be satisfactory as regards relative speed and reliability: Leco S analysis, X-ray fluorescence, and vacuum ICO emission spectroscopy.

The PDF includes an abstract in English.

  • Jarva, ORCID ID:E-mail:
  • Tervahauta, ORCID ID:E-mail:
article id 5376, category Article
Timo Pukkala. (1989). Predicting diameter growth in even-aged Scots pine stands with a spatial and non-spatial model. Silva Fennica vol. 23 no. 2 article id 5376. https://doi.org/10.14214/sf.a15533

The single tree growth models presented in this study were based on about 4,000 trees measured in 50 even-aged Scots pine (Pinus sylvestris L.) sample plots with varying density, spatial pattern of trees and stand age. Predictors that used information about tree locations decreased the relative standard error of estimate by 10 percentage points (15%), if past growth was not used as a predictor, and about 15 percentage points (30%) when past growth was one of the predictors. When ranked according to the degree of determination, the best growth models were obtained for the basal area increment, the next best for relative growth, and the poorest for diameter increment. The past growth decreased the relative standard error of estimate by 15–20 percentage points, but did not make the spatial predictors unnecessary. The degree of determination of the spatial basal area growth model was almost 80% if the past growth was unknown and almost 90% if the past growth was known. Variables that described the amount of removed competition did not improve the growth models.

The PDF includes an abstract in Finnish.

  • Pukkala, ORCID ID:E-mail:
article id 5375, category Article
Timo Pukkala. (1989). Prediction of tree diameter and height in a Scots pine stand as a function of the spatial pattern of trees. Silva Fennica vol. 23 no. 2 article id 5375. https://doi.org/10.14214/sf.a15532

The study presents two methods of predicting tree dimensions in a Scots pine (Pinus sylvestris L.) stand if only the location of trees is known. The first method predicts the tree diameter from the spatial location of neighbours. In the second method the diameter distribution of a subarea is estimated from the local stand density. This distribution is then sampled to obtain diameters. In both methods the tree height is predicted with a spatial model on the basis of diameters and locations of trees. The main purpose of the presented models is to generate realistic stands for simulation studies.

The PDF includes an abstract in Finnish.

  • Pukkala, ORCID ID:E-mail:
article id 5374, category Article
Finnish Society of Forest Science. (1989). Ohjeita kirjoittajille. Silva Fennica vol. 23 no. 1 article id 5374. https://doi.org/10.14214/sf.a15572
English title: Instructions to authors.
Keywords: Silva Fennica

This paper presents the publishing guidelines of the Finnish Society of Forest Science for the forest scientific serie of Silva Fennica. This paper presents the instructions to authors in Finnish, the English instructions are included in a separate PDF.  

  • Finnish Society of Forest Science, ORCID ID:E-mail:
article id 5373, category Article
Finnish Society of Forest Science. (1989). Instructions to authors. Silva Fennica vol. 23 no. 1 article id 5373. https://doi.org/10.14214/sf.a15571
Keywords: Silva Fennica

This paper presents the publishing guidelines of the Finnish Society of Forest Science for the forest scientific serie of Silva Fennica. This paper includes the instructions to authors in English, the Finnish instructions are in a separate PDF.

  • Finnish Society of Forest Science, ORCID ID:E-mail:
article id 5372, category Article
Jussi Kuusipalo, Mari-Anna Berg, Marja Mikkola, Helena Niemensivu. (1989). A cross-sectional population survey on the consumption pattern of berries and berry products in Finland. Silva Fennica vol. 23 no. 1 article id 5372. https://doi.org/10.14214/sf.a15531

The study is based on a questionnaire sent to 5,000 randomly sampled persons representing the adult population in Finland. The results give a picture of the amounts of berries preserved for home use and the consumption patterns of berries and berry products in the population and its various subgroups. Non-commercial berry consumption accounts for a considerable part of the total use of fruits and berries. However, use of berries and berry products decreases with the degree of urbanization and from older age classes to young. The results support the view that imported fruits and commercial juices are substitute products to domestic berries. It would appear that the consumer’s choice between fruits and berries is primarily regulated by the availability of berries.

The PDF includes an abstract in Finnish.

  • Kuusipalo, ORCID ID:E-mail:
  • Berg, ORCID ID:E-mail:
  • Mikkola, ORCID ID:E-mail:
  • Niemensivu, ORCID ID:E-mail:
article id 5371, category Article
Riitta Laurila. (1989). Pieniläpimittaisen männyn kuituominaisuudet. Silva Fennica vol. 23 no. 1 article id 5371. https://doi.org/10.14214/sf.a15530
English title: Fibre properties in Pinus sylvestris pulpwood.

Properties of fibres in pulpwood, especially length, width and the thickness of walls in tracheids, are essential for strength properties of pulp and paper. Length and width of tracheids increase from pith to surface in radial direction. Young and small-sized stems have also smaller fibres. Small-sized Pinus sylvestris L. test trees had tracheids that were shorter both in stems and knot wood than those in normal sized trees. However, cell walls in test trees were as thick as in normal sized trees. It seems that especially the L/T -ratio (length/thickness) in small stems is worse than in normal sized pulp wood.

The PDF includes an abstract in English.

  • Laurila, ORCID ID:E-mail:
article id 5370, category Article
Harri Rantonen, Juhani Päivänen. (1989). Kasvatusmetsien metsänhoidollinen tila ojitusalueilla puunkorjuun jälkeen. Silva Fennica vol. 23 no. 1 article id 5370. https://doi.org/10.14214/sf.a15529
English title: Silvicultural condition of tree stands after thinning on drained peatlands.

The area of stands studied by line plot survey was 594 ha. On the basis of the length of the inventory line the estimated proportion of harvesting strips was 14% and that of ditch openings 6% of the area. The calculated strip road spacing was 29 m. The option of the minimum diameter made it difficult to use the number of stems as criterion for thinning intensity. Thinning intensity evaluated according to the basal area had been stronger than recommended with low values of dominant height and milder with high values. The estimated removal according to stumps was 38 m3/ha on the average between the strips. The real removal has, however, been larger than that, as the strip road openings are made in connection with the first thinning.

The PDF includes an abstract in English.

  • Rantonen, ORCID ID:E-mail:
  • Päivänen, ORCID ID:E-mail:
article id 5369, category Article
Helen J. Jozefek. (1989). The effect of varying levels of potassium on the frost resistance of birch seedlings. Silva Fennica vol. 23 no. 1 article id 5369. https://doi.org/10.14214/sf.a15528

Seven hundred one-year-old Betula pendula Roth seedlings were given different concentrations of potassium fertilizer. Over the study period seedlings were subjected to artificial growing and dormant phases. Frost resistance of the seedlings was assessed by artificial freezing tests and electrical impedance measurements on stem cuttings. In general, high concentrations of potassium fertilizer reflected a low tolerance to frost. Pre-freezing impedance readings decreased with increasing potassium fertilizer dosages. Results from pre-freezing impedance measurements were found to be in broad agreement with the hypothesis that high impedance readings indicate a frost hardy tissue whereas low readings imply the opposite.

The PDF includes an abstract in Finnish.

  • Jozefek, ORCID ID:E-mail:
article id 5368, category Article
Kari Heliövaara, Rauno Väisänen. (1989). Invertebrates of young Scots pine stands near the industrial town of Harjavalta, Finland. Silva Fennica vol. 23 no. 1 article id 5368. https://doi.org/10.14214/sf.a15527

Invertebrates of young Scots pine (Pinus sylvestris L.) stands were preliminarily studied along a gradient of industrial air pollutants in Harjavalta, south-western Finland. Bark samples and net samples on pine branches and needles were taken in May–June, 1987. The number of aphids on needles was highest near the industrial plants. The number of mites in bark was positively correlated with the increasing distance from the pollutant source. Detrended correspondence analysis ordination calculated according to the bark invertebrates showed that the sampling sites of the zones far from the emission source formed a distinct group while those of the zones near the source were relatively widely dispersed indicating disturbances in faunal structure.

The PDF includes an abstract in Finnish.

  • Heliövaara, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
article id 5367, category Article
Kari Heliövaara, Rauno Väisänen. (1989). Quantitative variation in the elemental composition of Scots pine needles along a pollutant gradient. Silva Fennica vol. 23 no. 1 article id 5367. https://doi.org/10.14214/sf.a15526

Quantitative variation in the elemental composition of living Scots pine needles was studied along an atmospheric pollutant gradient in the surroundings of the industrial town Harjavalta, south-western Finland. Two 9-km-long transects, each with nine sample plots, running to the S and SW from factory complex were delimited in a homogenous Scots pine (Pinus sylvestris L.) forest. Needle samples were taken from 10 trees at each site, and from two separate sites in Tuusula near Helsinki. There was considerable spatial variation in the elemental composition of the needles. Heavy metals (Cu, Fe, Zn) showed a clear pattern of exponentially decreasing concentration with increasing distance from the emission source. Sodium and potassium concentrations, as well as the ash weight and air-dry weight, also decreased. Magnesium, manganese and calcium concentrations increased with increasing distance.

The PDF includes an abstract in Finnish.

  • Heliövaara, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:

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