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Articles by Heikki Korpunen
Category : Research article
article id 23065,
category
Research article
Pentti Niemistö,
Heikki Korpunen,
Yrjö Nuutinen.
(2024).
Harvesting efficiency and understory damage with different cutting methods on two storied stands of silver birch and Norway spruce.
Silva Fennica
vol.
58
no.
2
article id 23065.
https://doi.org/10.14214/sf.23065
Keywords:
productivity;
thinning;
costs;
harvesting damage;
mixed stand;
continuous cover;
multistorey forest
Highlights:
With careful, well-timed harvesting of overstory birch, it is possible to successfully use initial understory spruce in producing the next tree generation; Preserving understory spruce when cutting overstory birch reduced harvesting productivity by 30% in comparison to unpreserved harvesting; Removal of overstory birch had a positive correlation in cutting productivity but negative correlation in the quality of remaining understory spruce.
Abstract |
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Author Info
Uneven-aged forests set certain challenges for cut-to-length harvesting work. It is a challenge to cost-effectively remove larger trees while leaving a healthy understory for regrowth. The study’s aim was to evaluate productivity and costs of harvesting two-storied Silver birch (Betula pendula Roth) and Norway spruce (Picea abies (L.) H. Karst.) stands by creating time consumption models for cutting, and using existing models for forwarding. Damage to the remaining understory spruce was also examined. Four different harvesting methods were used: 1) all dominant birches were cut; 2) half of them thinned and understory was preserved; compared to 3) normal thinning of birch stand without understory; and 4) clear cutting of two-storied stand. Results showed the time needed for birch cutting was 26–30% lower when the understory was not preserved. Pulpwood harvesting of small sized spruces that prevent birch cutting was expensive, especially because of forwarding of small amounts with low timber density on the strip roads. Generally, when taking the cutting and forwarding into account, the unit cost at clear cuttings was lowest, due to lesser limitations on work. It was noted that with increasing removal from 100 to 300 m3 ha–1, the relative share of initial undamaged spruces after the harvest decreased from 65 to 50% when the aim was to preserve them. During summertime harvesting, the amount of stem damage was bigger than during winter. In conclusion, two-storied stands are possible to transit to spruce stands by accepting some losses in harvesting productivity and damages on remaining trees.
-
Niemistö,
Natural Resources Institute Finland (Luke), Natural resources, Kampusranta 9 C, FI-60320 Seinäjoki, Finland
https://orcid.org/0000-0002-9152-2108
E-mail:
ext.pentti.niemisto@luke.fi
-
Korpunen,
Norsk institutt for bioøkonomi (NIBIO), Division of Forest and Forest Resources, Department of Forest operations and digitalization, Divisjon for skog og utmark, Avdeling for Driftsteknikk og digitalisering, Høgskoleveien 8, 1433 Ås, Norway
https://orcid.org/0000-0001-9749-5684
E-mail:
heikki.korpunen@nibio.no
-
Nuutinen,
Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6 B, FI-80100 Joensuu, Finland
https://orcid.org/0000-0003-3360-4444
E-mail:
yrjo.nuutinen@luke.fi
article id 67,
category
Research article
Pentti Niemistö,
Heikki Korpunen,
Ari Laurén,
Marika Salomäki,
Jori Uusitalo.
(2012).
Impact and productivity of harvesting while retaining young understorey spruces in final cutting of downy birch (Betula pubescens).
Silva Fennica
vol.
46
no.
1
article id 67.
https://doi.org/10.14214/sf.67
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Author Info
- Niemistö, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: pn@nn.fi
- Korpunen, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: hk@nn.fi
- Laurén, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: al@nn.fi
- Salomäki, Finnish Forest Research Institute, Parkano & Joensuu, Finland E-mail: ms@nn.fi
-
Uusitalo,
Finnish Forest Research Institute, Parkano & Joensuu, Finland
E-mail:
jori.uusitalo@metla.fi
article id 177,
category
Research article
Tuomo Nurminen,
Heikki Korpunen,
Jori Uusitalo.
(2009).
Applying the activity-based costing to cut-to-length timber harvesting and trucking.
Silva Fennica
vol.
43
no.
5
article id 177.
https://doi.org/10.14214/sf.177
Keywords:
logistics;
bucking;
cutting;
forest transport;
long-distance transportation;
trucking;
time consumption;
timber assortment;
cost driver
Abstract |
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The supply chain of the forest industry has increasingly been adjusted to the customer’s needs for precision and quality. This has changed the operative environment both in the forest and on the roads. As the total removal of timber is increasingly divided into more log assortments, the lot size of each assortment decreases and the time consumed in sorting the logs increases. In this respect, the extra assortments have made harvesting work more difficult and affected the productivity of both cutting and forest transport; this has thus increased the harvesting costs. An activity-based cost (ABC) management system is introduced for timber harvesting and long-distance transport, based on the cut-to-length (CTL) method, in which the logistic costs are assigned to timber assortments and lots. Supplying timber is divided into three main processes: cutting, forest transport, and long-distance transportation. An ABC system was formulated separately for each of these main operations. Costs were traced to individual stands and to timber assortment lots from a stand. The cost object of the system is thus a lot of timber that makes up one assortment that has been cut, forwarded, and transported from the forest to the mill. Application of the ABC principle to timber harvesting and trucking was found to be relatively easy. The method developed gives estimates that are realistic to actual figures paid to contractors. The foremost use for this type of costing method should be as a tool to calculate the efficiency of an individual activity or of the whole logistic system.
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Nurminen,
Metsätoimisto Tuomo Nurminen, Joensuuntie 5 B 8, FI-41800 Korpilahti, Finland
E-mail:
tn@nn.fi
- Korpunen, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: hk@nn.fi
- Uusitalo, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: ju@nn.fi
article id 346,
category
Research article
Tuomo Nurminen,
Heikki Korpunen,
Jori Uusitalo.
(2006).
Time consumption analysis of the mechanized cut-to-length harvesting system.
Silva Fennica
vol.
40
no.
2
article id 346.
https://doi.org/10.14214/sf.346
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The time consumption and productivity of harvesting are dependent on stand conditions, the operators’ skills, working techniques and the characteristics of the forestry machinery. Even if the basic methods and machine types of the cut-to-length harvesting system have not changed significantly in 10 to 15 years, improvements in the operators’ competence, technical solutions in forest machinery and changes in the working environment have undoubtedly taken place. In this study, the objective was to discover the special characteristics in the time consumption of mechanized cutting and forest haulage in Finnish conditions. The empirical time study was conducted with professional operators and medium-sized single-grip harvesters and forwarders in final fellings and thinnings in easy terrain in central Finland. The models for effective time consumption in the work phases and total productivity were formed. Stem size, tree species and bucking affected the cutting, whereas timber density on the strip road, the average driving distance, load capacity, wood assortment and the bunching result of the harvester operator had an effect on the forest haulage performance. The results may be used in simulations, cost calculations and education.
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Nurminen,
University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland
E-mail:
tuomo.nurminen@joensuu.fi
- Korpunen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hk@nn.fi
- Uusitalo, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: ju@nn.fi
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