Category :
Editorial
article id 24058,
category
Editorial
Henrik Heräjärvi.
(2024).
Wood is much more than just carbon.
Silva Fennica
vol.
58
no.
4
article id 24058.
https://doi.org/10.14214/sf.24058
article id 10790,
category
Editorial
Henrik Heräjärvi.
(2022).
What do engineered wood products and Ford Model T have in common?
Silva Fennica
vol.
56
no.
3
article id 10790.
https://doi.org/10.14214/sf.10790
article id 10566,
category
Editorial
Henrik Heräjärvi.
(2021).
Science as a decision-support tool in forest policies.
Silva Fennica
vol.
55
no.
2
article id 10566.
https://doi.org/10.14214/sf.10566
article id 10216,
category
Editorial
Henrik Heräjärvi.
(2019).
New age of discovery in wood science.
Silva Fennica
vol.
53
no.
2
article id 10216.
https://doi.org/10.14214/sf.10216
Category :
Research article
article id 10389,
category
Research article
Juho Matala,
Harri Kilpeläinen,
Henrik Heräjärvi,
Tapio Wall,
Erkki Verkasalo.
(2020).
Sawlog quality and tree dimensions of Scots pine 34 years after artificial moose browsing damage.
Silva Fennica
vol.
54
no.
3
article id 10389.
https://doi.org/10.14214/sf.10389
Highlights:
The first controlled, long-term, experimental study on the tree dimensions and sawlog quality after moose damage; The trees damaged at the seedling stage had a smaller diameter, height, and tree volume at the end of the experiment; The heavier the clipping treatment, the more likely the stem form deteriorated; Deteriorated stem form and vertical branches were the most typical defects.
Abstract |
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Moose (Alces alces L.) browsing causes severe damage in Scots pine (Pinus sylvestris L.) seedling stands. The effects of this damage on the quality of sawlogs were studied in a long-term controlled experiment. This article reports the stem size and external quality characteristics of Scots pine stems 34 years after artificial moose browsing damage. Damaging the trees by clipping the main stem at the seedling stage reduced the diameter, height, and tree volume of the trees at the end of the experiment. The tree growth reduction was dependent on the severity of clipping. The differences between the damaged and the control trees were more obvious in diameter than in height at the time of final felling. Stem form defects and vertical branches were the most typical externally detectable defects caused by clipping. Defects in the butt logs were detected in 71–89% of the damaged trees, depending on the clipping treatment severity. The stronger the clipping treatment, the more likely the stem form was defected and the more commonly were vertical branches and crooks detected in the stems. The results indicate that both tree dimensions and stem quality suffer from moose browsing. The findings of this controlled experiment more likely underestimate than overestimate the damage in comparison to real moose browsing. Further analyses are required to assess the effects of browsing damage on the internal quality of sawlogs and subsequent economic outcomes.
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Matala,
Natural Resources Institute Finland (Luke), Natural resources, Yliopistokatu 6B, FI-80101 Joensuu, Finland
E-mail:
juho.matala@luke.fi
-
Kilpeläinen,
Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6B, FI-80101 Joensuu, Finland
E-mail:
harri.kilpelainen@luke.fi
-
Heräjärvi,
Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6B, FI-80101 Joensuu, Finland
E-mail:
henrik.herajarvi@luke.fi
-
Wall,
Natural Resources Institute Finland (Luke), Research infrastructure services, Yliopistokatu 6B, FI-80101 Joensuu, Finland
E-mail:
tapio.wall@luke.fi
-
Verkasalo,
Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6B, FI-80101 Joensuu, Finland
E-mail:
erkki.verkasalo@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.
Abstract |
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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.
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Niemistö,
Natural Resources Institute Finland (Luke), Natural resources, Kampusranta 9 C, FI-60320 Seinäjoki, Finland
E-mail:
pentti.niemisto@luke.fi
-
Kilpeläinen,
Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland
E-mail:
harri.kilpelainen@luke.fi
-
Heräjärvi,
Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland
E-mail:
henrik.herajarvi@luke.fi
article id 117,
category
Research article
Harri Kilpeläinen,
Jari Lindblad,
Henrik Heräjärvi,
Erkki Verkasalo.
(2011).
Saw log recovery and stem quality of birch from thinnings in southern Finland.
Silva Fennica
vol.
45
no.
2
article id 117.
https://doi.org/10.14214/sf.117
Abstract |
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The objective of this study was to examine the timber quality of silver birch (Betula pendula Roth) and European white birch (Betula pubescens Ehrh.) trees in the first and second thinnings in southern parts of Finland, from the viewpoint of sawing of small-diameter, short logs, in particular. The average stem volume of birch was 0.140 m3 in the first thinning stands and 0.206 m3 in the second thinning stands. In planted stands, the trees were larger in the first thinnings but slightly smaller in the second thinnings, compared with naturally regenerated pure birch stands or mixed stands of Norway spruce and birch species. Almost 60% of the harvested and 35% of the remaining stems that could provide saw logs were graded as pulpwood for timber quality due to the occurrence of stem defects. The most common stem defects were multiple crooks and middle crooks. Only minor between-stratum differences were detected in the numbers of defects. Depending on the bucking option, the total percentage of saw and plywood logs from the total birch recovery in the thinning of the sample stands varied between 11.7 and 18.2. The recovery of saw logs was clearly higher in the second thinnings, 12–19%, than in the first thinnings, 8–14%. Of the stand types, saw log recovery was the highest in planted birch stands, 12–19%, but lower in naturally regenerated pure birch stands and mixed stands of Norway spruce and birch. The highest share of saw logs was in the second thinning of planted stands, 17–25%. This study shows that the harvesting recoveries of end-use based timber assortments can be estimated in different kinds of thinning birch stands. Based on tree and log dimensions and stem squality, silver birch firstly from plantations and secondly from mixed stands should be the most interesting source of raw material for the saw milling, furniture and interior product sectors.
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Kilpeläinen,
Finnish Forest Research Institute, Eastern Finland Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
hk@nn.fi
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Lindblad,
Finnish Forest Research Institute, Eastern Finland Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
jl@nn.fi
-
Heräjärvi,
Finnish Forest Research Institute, Eastern Finland Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
henrik.herajarvi@metla.fi
-
Verkasalo,
Finnish Forest Research Institute, Eastern Finland Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
ev@nn.fi
article id 198,
category
Research article
Henrik Heräjärvi.
(2009).
Effect of drying technology on aspen wood properties.
Silva Fennica
vol.
43
no.
3
article id 198.
https://doi.org/10.14214/sf.198