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Articles containing the keyword 'pruning'.

Category: Research article

article id 10052, category Research article
Pentti Niemistö, Harri Kilpeläinen, Henrik Heräjärvi. (2019). Effect of pruning season and tool on knot occlusion and stem discolouration in Betula pendula – situation five years after pruning. Silva Fennica vol. 53 no. 1 article id 10052. https://doi.org/10.14214/sf.10052
Highlights: The occlusion was the fastest in the case of small living branches of fast growing trees pruned in springtime; Occlusion was quicker after saw pruning than after secateurs pruning, due to shorter knot stubs; Branches that were pruned in living state occluded faster than the ones pruned as dead; Dead branches hit down with a stick occluded slowly.

This paper investigates and models the effects of pruning season and tool on wound occlusion with varying tree and branch characteristics of silver birch (Betula pendula Roth) stems at the pruning height of 0−4 metres. Dates of eight secateurs prunings, three saw prunings and two sticks prunings as well as unpruned control were tested in permanent plots on four sites. Knot occlusion and discolouration in stemwood were measured from about 1600 studied knots of 112 sample trees felled five to six years after pruning in 2010. Knot occlusion rate was modelled according to pruning tool, date, tree growth, and branch characteristics. The occlusion was the fastest in trees pruned in spring or early summer, and the slowest in trees pruned in autumn. Stubs of living branches occluded faster than the dead ones with the same diameter. Saw pruning resulted in clearly better occlusion rates than secateurs pruning, caused by the shorter knot stubs after saw pruning. Hitting dead branches away with a stick resulted in the worst occlusion status. The colour defects spread more often upward from the knot than downward. Discolouration in stemwood was detected more frequently near to the pruned branches than the unpruned ones, and more widely near to the stubs of dead branches than the living ones. Most saw and secateurs pruned branches were completely occluded during the experiment, so these prunings were suitable for all branches under 20 mm in diameter, and for living branches even up to 30 mm in fast-growing trees.

  • Niemistö, Natural Resources Institute Finland (Luke), Natural resources, Kampusranta 9 C, FI-60320 Seinäjoki, Finland ORCID ID:E-mail: pentti.niemisto@luke.fi (email)
  • Kilpeläinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland ORCID ID:E-mail: harri.kilpelainen@luke.fi
  • Heräjärvi, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland ORCID ID:E-mail: henrik.herajarvi@luke.fi
article id 10052, category Research article
Pentti Niemistö, Harri Kilpeläinen, Henrik Heräjärvi. (2019). Effect of pruning season and tool on knot occlusion and stem discolouration in Betula pendula – situation five years after pruning. Silva Fennica vol. 53 no. 1 article id 10052. https://doi.org/10.14214/sf.10052
Highlights: The occlusion was the fastest in the case of small living branches of fast growing trees pruned in springtime; Occlusion was quicker after saw pruning than after secateurs pruning, due to shorter knot stubs; Branches that were pruned in living state occluded faster than the ones pruned as dead; Dead branches hit down with a stick occluded slowly.

This paper investigates and models the effects of pruning season and tool on wound occlusion with varying tree and branch characteristics of silver birch (Betula pendula Roth) stems at the pruning height of 0−4 metres. Dates of eight secateurs prunings, three saw prunings and two sticks prunings as well as unpruned control were tested in permanent plots on four sites. Knot occlusion and discolouration in stemwood were measured from about 1600 studied knots of 112 sample trees felled five to six years after pruning in 2010. Knot occlusion rate was modelled according to pruning tool, date, tree growth, and branch characteristics. The occlusion was the fastest in trees pruned in spring or early summer, and the slowest in trees pruned in autumn. Stubs of living branches occluded faster than the dead ones with the same diameter. Saw pruning resulted in clearly better occlusion rates than secateurs pruning, caused by the shorter knot stubs after saw pruning. Hitting dead branches away with a stick resulted in the worst occlusion status. The colour defects spread more often upward from the knot than downward. Discolouration in stemwood was detected more frequently near to the pruned branches than the unpruned ones, and more widely near to the stubs of dead branches than the living ones. Most saw and secateurs pruned branches were completely occluded during the experiment, so these prunings were suitable for all branches under 20 mm in diameter, and for living branches even up to 30 mm in fast-growing trees.

  • Niemistö, Natural Resources Institute Finland (Luke), Natural resources, Kampusranta 9 C, FI-60320 Seinäjoki, Finland ORCID ID:E-mail: pentti.niemisto@luke.fi (email)
  • Kilpeläinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland ORCID ID:E-mail: harri.kilpelainen@luke.fi
  • Heräjärvi, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland ORCID ID:E-mail: henrik.herajarvi@luke.fi
article id 179, category Research article
Henna Vartiamäki, Jarkko Hantula, Antti Uotila. (2009). Susceptibility of silver birch pruning wounds to infection by white-rot fungus (Chondrostereum purpureum), a potential bioherbicide. Silva Fennica vol. 43 no. 4 article id 179. https://doi.org/10.14214/sf.179
We artificially inoculated pruning wounds of silver birch (Betula pendula Roth) to study seasonal variation in their vulnerability to infection by the fungal decomposer Chondrostereum purpureum (Pers. ex Fr.) Pouzar. This information is critical to the assessment of incidental infection risks in areas where C. purpureum may be used as a bioherbicide. On seven monthly occasions between April and October 2005, 30 birch trees were pruned to yield a total of 210 experimental trees. On each occasion, 10 trees were inoculated immediately with C. purpureum mycelium, 10 were inoculated with blank inoculum and 10 were only pruned. In the summer of 2007, a survey of 129 experimental trees showed that pruning wounds were most susceptible to infection during May. Treatment with C. purpureum at other times during the growing season also increased the extent of discoloration or decay but the effect was considerably less.
  • Vartiamäki, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: henna.vartiamaki@metla.fi (email)
  • Hantula, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail:
  • Uotila, University of Helsinki, Hyytiälä Forestry Field Station, Hyytiäläntie 124, FI-35500 Korkeakoski, Finland ORCID ID:E-mail:
article id 258, category Research article
Ursula Schatz, Henrik Heräjärvi, Kari Kannisto, Matti Rantatalo. (2008). Influence of saw and secateur pruning on stem discolouration, wound cicatrisation and diameter growth of Betula pendula. Silva Fennica vol. 42 no. 2 article id 258. https://doi.org/10.14214/sf.258
The aim of this case study was to compare the impacts of saw and secateur pruning on silver birch (Betula pendula Roth). Data were collected from two saw pruned stands in 2005, and one secateur pruned stand in 2003. All the stands were located in southern Finland. The sample stems were felled, and their butt logs were sawn into flitches, whose knot features and colour defects were measured. In addition, discs were sawn from each stem in order to study the annual ring widths. In this material, pruning with secateurs appeared to cause less colour defects than pruning with a saw. Irrespective of the pruning method used, the colour defects in the stem wood were at their largest in cases where the basal knob or the stem bark appeared to be damaged by pruning. Colour defects spread mainly towards the pith, only in a few cases towards the stem surface. The cicatrisation time of the knots as well as the length of the bark stick remaining inside the stem did not show significant differences between the two pruning methods. Pruning of the lowest living branches appears to have no effect on the diameter growth of silver birch trees.
  • Schatz, Peltotievantie 27, FI-99440 Leppäjärvi, Finland ORCID ID:E-mail:
  • Heräjärvi, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: henrik.herajarvi@metla.fi (email)
  • Kannisto, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland ORCID ID:E-mail:
  • Rantatalo, Peltotievantie 27, FI-99440 Leppäjärvi, Finland ORCID ID:E-mail:

Category: Article

article id 7167, category Article
Veijo Heiskanen. (1966). Tutkimuksia rauduskoivikon karsimisen kannattavuudesta. Acta Forestalia Fennica vol. 81 no. 2 article id 7167. https://doi.org/10.14214/aff.7167
English title: Studies on the profitability of pruning of common birch (Betula pendula) stands.

The objective of the present investigation was to clarify the profitability of pruning silver birch (Betula verrucosa, now Betula pendula Roth) in the growing of raw material for veneer industry. Calculations were made on the grade, value, and price of pruned and untreated butt logs as well as on costs of pruning and the development of pruned trees.

The grade distribution of unpruned veneer butt logs, the grade distribution of the veneer yield, and consequently, the value of veneer yield and log prices at the plant are considerably better than those of average logs. The grade, value and price increased with increasing diameter. The value and price of pruned butt logs depended primarily on the difference between the turning pruning diameters, and their increase with decreasing pruning diameter and increasing turning diameter. The value of pruned butt logs is always considerably higher than that of unpruned logs. The increase in the value correlates to the pruning and turning diameters, and is, for example, in rotary-cut logs which have been pruned when 10 cm in diameter 80–130%.

Pruning increases the stumpage in naturally regenerated silver birch stands on Oxalis-Myrtillus site by 2,000–3,000 Fmk/ha when employed at 20 years of stand age and rotary cutting at 60–80 years of age respectively. The average pruning costs on Oxalis-Myrtillus site are 51–57 Fmk/ha.

The PDF includes a summary English.

  • Heiskanen, ORCID ID:E-mail:
article id 5628, category Article
Séverine Le Dizès, Philippe Balandier, Pierre Cruiziat, Patrick Jacquet, André Lacointe, Xavier Le Roux, Hervé Sinoquet. (1997). A model for simulating structure-function relationships in walnut tree growth processes. Silva Fennica vol. 31 no. 3 article id 5628. https://doi.org/10.14214/sf.a8530

An ecophysiological growth process model, called INCA, for simulating the growth and development of a young walnut tree (Juglans regia L.) during three or four years, is presented. This tool, currently under development, aims at integrating architectural and physiological knowledge of the processes involved, in order to give a more rational understanding of the pruning operation. The model describes a simple three-dimensional representation of tree crown, solar radiation interception, photosynthesis, respiration, growth and partitioning of assimilates to leaves, stems, branches and roots. It supports the hypothesis that the tree grows as a collection of semiautonomous, interacting organs that compete for resources, based on daily sink strengths and proximity to sources. The actual growth rate of organs is not predetermined by empirical data, but reflects the pattern of available resources. The major driving variables are solar radiation, temperature, topological, geometrical and physiological factors. Outputs are hourly and daily photosynthate production and respiration, daily dimensional growth, starch storage, biomass production and total number of different types of organ. The user can interact or override any or all of the input variables to examine the effects of such changes on photosynthate production and growth. Within INCA, the tree entities and the surrounding environment are structured in a frame-based representation whereas the processes are coded in a rule-based language. The simulation mechanism is primarily based on the rule chaining capabilities of an inference engine.

  • Le Dizès, ORCID ID:E-mail:
  • Balandier, ORCID ID:E-mail:
  • Cruiziat, ORCID ID:E-mail:
  • Jacquet, ORCID ID:E-mail:
  • Lacointe, ORCID ID:E-mail:
  • Le Roux, ORCID ID:E-mail:
  • Sinoquet, 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 5185, category Article
Seppo Kellomäki. (1983). Männyn oksien murtolujuus. Silva Fennica vol. 17 no. 2 article id 5185. https://doi.org/10.14214/sf.a15101
English title: Strength of Scots pine branches.

Empirical measurements showed that the strength of a dead branch of Scots pine (Pinus sylvestris L.) was related to the second power of the branch diameter and the third power of the basic density of branch wood. The same factors affected also the strength of living branches. Especially, the contribution of wood density was important. The significance of the results is discussed considering the natural process of self-pruning and its effect on the branchiness of the stem.

The PDF includes a summary in English.

  • Kellomäki, ORCID ID:E-mail:
article id 5018, category Article
Pertti Laakso, Olli Saikku. (1979). Havaintoja karsituista männyistä sorvatun viilun laadusta. Silva Fennica vol. 13 no. 1 article id 5018. https://doi.org/10.14214/sf.a14872
English title: Observations on the quality of veneer from pruned Scots pine stems.
Original keywords: mänty; pystykarsinta; vaneri; laatu; viilu

The material was obtained from Scots pine (Pinus sylvestris L.) stems which were pruned 27 years earlier up to the height of 5–6 m. Rotary cutting was made from 16 pruned stems and 3 unpruned ones. The length of bolts was 70 cm and the thickness of veneer 1.5 mm. The proportion of good quality veneer was 46% in pruned stems and 14% in the others. Veneer with exellent quality was obtained from pruned stems up to the height of tree meters, that is to say a little under the pruning line.
The PDF includes a summary in English.

  • Laakso, ORCID ID:E-mail:
  • Saikku, ORCID ID:E-mail:
article id 5010, category Article
Jyrki Raulo, Reino Saarnio, Timo Ylitalo. (1978). Visakoivun karsittujen oksien kyljestyminen ja värivian leviäminen niistä runkoon. Silva Fennica vol. 12 no. 4 article id 5010. https://doi.org/10.14214/sf.a14864
English title: Sealing-off of pruned branch stumps in curly birch and subsequent spread of discoloration into the stemwood.

The material used in this study was collected in 1975 from a 41-years old curly birch (Betula pendula f. carelica Sok.) stand in Southern Finland, which had been pruned 12 years earlier. While the stand was thinned, 26 felled trees were selected for further study to study occurrence of discoloration originating from of pruned branches.

The study material included 35 pruned branch stumps and 38 naturally pruned branch stumps of curly birch. The mean diameter of the former was 31 mm and of the latter, only 15 mm. Of the pruned branch stumps, 23% had become completely sealed-off within 12 years. The discoloration had spread into the stem as little from pruned branch stumps as from naturally pruned ones even though the former were greater in diameter. Advanced rot was not found in any of the samples studied.

The PDF includes a summary in English.

  • Raulo, ORCID ID:E-mail:
  • Saarnio, ORCID ID:E-mail:
  • Ylitalo, ORCID ID:E-mail:
article id 7662, category Article
Antti Uotila. (1990). Infection of pruning wounds in Scots pine by Phacidium coniferarum and selection of pruning season. Acta Forestalia Fennica no. 215 article id 7662. https://doi.org/10.14214/aff.7662

The Scots pine (Pinus sylvestris L.) pruning experiments were established in different geographical regions of Finland. The pines were pruned in 16 different times during the year. Half of the trees were inoculated with conidia of Phacidium coniferarum (Hahn). Annual cankers were produced in the inoculated trees pruned during October–December. The safe pruning season ended in autumn when the five-day mean temperature decreased below +7°C. The unsafe pruning season terminated when the temperature remained permanently over 0°C. Dry-pruned branches were infected only if the phloem had been wounded. The mycelia of the fungus were pathogenic in the phloem in the inoculations made from October to March. The fungus occurred commonly in slash and in pines wounded during the autumn. The fungus has a one-year life cycle.

The PDF includes a summary in Finnish.

  • Uotila, ORCID ID:E-mail:
article id 7662, category Article
Antti Uotila. (1990). Infection of pruning wounds in Scots pine by Phacidium coniferarum and selection of pruning season. Acta Forestalia Fennica no. 215 article id 7662. https://doi.org/10.14214/aff.7662

The Scots pine (Pinus sylvestris L.) pruning experiments were established in different geographical regions of Finland. The pines were pruned in 16 different times during the year. Half of the trees were inoculated with conidia of Phacidium coniferarum (Hahn). Annual cankers were produced in the inoculated trees pruned during October–December. The safe pruning season ended in autumn when the five-day mean temperature decreased below +7°C. The unsafe pruning season terminated when the temperature remained permanently over 0°C. Dry-pruned branches were infected only if the phloem had been wounded. The mycelia of the fungus were pathogenic in the phloem in the inoculations made from October to March. The fungus occurred commonly in slash and in pines wounded during the autumn. The fungus has a one-year life cycle.

The PDF includes a summary in Finnish.

  • Uotila, ORCID ID:E-mail:
article id 4720, category Article
Veijo Heiskanen. (1963). Aikatutkimuksia koivun karsimisesta. Silva Fennica no. 115 article id 4720. https://doi.org/10.14214/sf.a14279
English title: Time studies in the pruning of birch.

On the basis of time studies on pruning, one thousand stems in four stands was pruned, carried out in 1962. The work was done in two phases with Olli pruning saw, first attached to a shaft about 1.8 metres long and the to a shaft about 4 metres long.

The total time of moving from one stem to another when pruning the stem varied from 0,28 to 0.31 min per stem in the different working sites. The resting time was 19–20% of the effective working time, which included actual pruning time and the moving time. In average, 7.5% of the actual pruning time was unproductive. The actual pruning took in average 0.75–1.1 min/stem in the different sites. The time depended on size of the tree, the DBH, and on the length of the part to be pruned. The total working site time for the pruning was in average 1.34–1.98 min/stem. The output of the work per 7 hours’ working day varied from 226 to 280 stems, and the costs from 10 to 14 pennies per stem.

The PDF includes a summary in English.

  • Heiskanen, ORCID ID:E-mail:
article id 4516, category Article
M. Lappi-Seppälä. (1937). Karsimisesta arvopuun kasvatusta silmällä pitäen. Silva Fennica no. 42 article id 4516. https://doi.org/10.14214/sf.a14094
English title: Pruning as a means to produce quality timber.

 

 

  • Lappi-Seppälä, ORCID ID:E-mail:

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