Current issue: 53(2)

Under compilation: 53(3)

Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'crown class'.

Category: Article

article id 7354, category Article
P. S. Tikka. (1940). Puiden vikanaisuuksien merkitys ja huomioon ottaminen Perä-Pohjolan mäntymetsien hoidossa. Acta Forestalia Fennica vol. 50 no. 1 article id 7354. https://doi.org/10.14214/aff.7354
English title: The effect of injuries in trees on forest management of Scots pine stands in Northern Finland.

The aim of the study was to find out what are the causes of damage in Scots pine (Pinus sylvestris L.) stands and the frequency of different kinds of injuries, which are then discussed in relation to the silvicultural state and management of the stands in comparison to ideal forests. Sample plots were studied in over 80-year old Scots pine dominated stands in mineral soil sites of different forest types in Northern Finland in the area of Perä-Pohjola. 10–40 trees were chosen as sample trees in each sample plot. The sample trees were felled, and the diameter, height of crown and injuries outside and inside of the stem were recorded.

Length of knot-free part of the stem was higher in the dominant trees and in older age classes of the trees. The form of the stem becomes broader and rounder with the age. The crowns are, however, longer in Northern Finland compared to Southern Finland. In management of Scots pine stands, all trees diseased by Scots pine blister rust (Cronartium flaccidum) should be removed. The disease is common in Northern Finland, and the number of diseased trees increases as the stands get older. Decay was more common in trees that had fire wounds. In general, injuries decreased the length and diameter growth of the trees. From the dominant trees should only injured and diseased trees removed in the thinnigs. Codominant trees can be left to grow when spare trees are needed to replace missing dominant trees. Detailed instruction of selection of the removed trees are given for each age class.

The PDF includes a summary in German.

  • Tikka, ORCID ID:E-mail:
article id 7251, category Article
Lauri Ilvessalo. (1929). Puuluokitus ja harvennusasteikko. Acta Forestalia Fennica vol. 34 no. 38 article id 7251. https://doi.org/10.14214/aff.7251
English title: Utilization of tree classification in thinnings.
English keywords: crown class; thinning method

Doctor Lauri Ilvessalo modified tree classification developed by professor Gunnar Schotte to develop a tree classification and thinning system that suited Finnish conditions. His system was first applied when the Finnish Forest Research Institute began thinning experiments in a large scale in 1924. The system distinguishes four crown storeys: the predominating crown storey, dominated crown storey, emergent trees and undergrowth. Into the predominating storeys belong dominant trees and co-dominant trees, and into the dominated storeys the intermediate and ground trees. The trees in all the storeys can be divided in to normal trees with well-formed crown and stem, trees with defectively developed crown, trees with defective stem, and injured and diseased trees. The article describes different thinning methods (cleaning thinning, selective thinning from below, selective thinning from above, increment felling, freeing felling) using the tree-classification.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in English.

  • Ilvessalo, ORCID ID:E-mail:
article id 7048, category Article
O. J. Lakari. (1920). Tutkimuksia männyn muodosta. Acta Forestalia Fennica vol. 16 no. 6 article id 7048. https://doi.org/10.14214/aff.7048
English title: Studies on the stem and crown form of Scots pine.
English keywords: stem form; canopy layer; crown class

Crown class is useful tool both in forest management and forest mensuration. The study presents a detailed crown classification for Scots pine (Pinus sylvestris L.). It was used to classify the sample trees prior detailed measurements of the crown and stem form. The stem form of a tree was dependent on which canopy layer it belonged. This relation was detected on both Vaccinium and Calluna site type forests. In addition, the stem tapers faster in poorer forest site types compared to better sites. The shorter the self-pruned part of the stem is, the faster the stem tapers. According to the study, the stems of stunted trees taper faster than trees of other crown classes. Also the age group affects stem form.

The PDF includes a summary in German.

  • Lakari, ORCID ID:E-mail:
article id 5116, category Article
Seppo Kellomäki, Pauline Oker-Blom. (1981). Specific needle area of Scots pine and its dependence on light conditions inside the canopy. Silva Fennica vol. 15 no. 2 article id 5116. https://doi.org/10.14214/sf.a15057

The specific needle area of young Scots pine (Pinus sylvestris L.) showed a substantial within-tree and between-tree variation which was associated with the position of the tree and the position of the whorl as indicated by the prevailing crown and branch illumination. In suppressed trees the values of the specific needle area were three to four times those in dominating trees. A similar morphogenesis was discernible in comparison of the lower and the upper part of the crown. The mean specific needle area value for the whole stand was 184 cm2/g.

The PDF includes a summary in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Oker-Blom, ORCID ID:E-mail:
article id 5079, category Article
Seppo Kellomäki, Pertti Hari, Pirkko Ilonen, Markku Kanninen. (1980). Eco-physiological studies on young Scots pine stands. II. Silva Fennica vol. 14 no. 3 article id 5079. https://doi.org/10.14214/sf.a15020

The technique of double normalizing, i.e. normalizing the relative needle biomass and the length of the living crown system, is applied to the modelling of the distribution of needle biomass in the canopy of young Scots pine (Pinus sylvestris L.) stands. The study based on the parameters of β-function shows that at the individual-tree level, the variance in needle distribution was not closely associated with any tree characteristics. A shift in the point of maximum needle biomass upwards unsuppressed trees was, however, evident. This was associated with an increase in the height of the trees. At the stand level, the stand mean height and stand density had an equal and a rather high potential for explaining the variance in the needle distribution. The normalized crowns are utilized in models for determining light extinction in the crown. A special technique for determining the amount of photosynthates available for growth in a particular tree is presented.

The PDF includes a summary in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Hari, ORCID ID:E-mail:
  • Ilonen, ORCID ID:E-mail:
  • Kanninen, ORCID ID:E-mail:

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