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Articles containing the keyword 'scaling'

Category : Article

article id 4950, category Article
Matti Kärkkäinen. (1976). Lisähavaintoja haapatukkien poikkipinta-alan mittaamisesta. Silva Fennica vol. 10 no. 4 article id 4950. https://doi.org/10.14214/sf.a14796
English title: Auxiliary observations on the measurement of the cross-sectional area of aspen logs.
Original keywords: puutavaranmittaus; tukit; läpimitta; haapa; poikkipinta-ala
English keywords: logs; diameter; cross-sectional area; aspen; timber scaling
Abstract | View details | Full text in PDF | Author Info

In this study the area, 8 diameters, and 16 radii were measured of 174 discs representing aspen logs in a mill. The average difference between the largest and smallest diameter was 18 mm, or 7% of the longest diameter. The difference between the largest and smallest radius was 29 mm, or 22% of the longest radius. The diameter was on the average 2.4 mm longer than the two corresponding radii.

The exact area of each disc was measured using a planimeter. In comparison, the area based on the circle formula the diameter being the arithmetic mean of largest and smallest diameters overestimated the area by 1.7%. The results also indicated that the use of random direction in the measurement of diameter overestimated the cross-sectional area on the average by 1.8%.

The study is continuation of the earlier study where the bibliography is presented. As far as the results are comparable, they support each other.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4925, category Article
Matti Kärkkäinen. (1975). Pohjoissuomalaisten mäntytukkien soikeus. Silva Fennica vol. 9 no. 4 article id 4925. https://doi.org/10.14214/sf.a14767
English title: Ovalness of Scots pine logs in Northern Finland.
Original keywords: Pohjois-Suomi; mänty; puutavaranmittaus; läpimitta; sahatukki
English keywords: Pinus sylvestris; Scots pine; saw logs; northern Finland; diameter; timber scaling
Abstract | View details | Full text in PDF | Author Info

The material of this study consists of 1,080 Scots pine (Pinus sylvestris L.) saw logs measures in two saw mills in Northern Finland. The largest and the smallest top-diameter of each log was measured under bark. According to the results, the ovalness was rather small, 1 mm or 4.9% on average. On the other hand, only 14.3% of all logs showed a diameter difference smaller than 2%. The ovalness was larger than 10% in 5.8% of all logs.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4922, category Article
Matti Kärkkäinen. (1975). Koivu- ja haapatukkien poikkipinta-alan mittaaminen. Silva Fennica vol. 9 no. 3 article id 4922. https://doi.org/10.14214/sf.a14764
English title: Measurement of the cross-sectional area of birch and aspen logs.
Original keywords: puutavaranmittaus; koivu; tukit; läpimitta; haapa; poikkipinta-ala
English keywords: Populus tremula; birch; Betula; logs; cross-section; aspen; timber scaling
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to determine the extent to which the cross section of birch (Betula sp.) and aspen (Populus tremula L.) logs differ from a circle and to test some simple methods for measuring the cross-sectional area which can be used, for instance, for determining the volume of the logs. The material consisted of 420 debarked birch disks and 240 aspen disks which were representative of the logs arriving at two factories.

The convex deficit values for the material were very small, the cross-sectional area error being in general less than 1%. On the other hand, the other parameters deviated from the circular form to quite a large degree. It was also evident that the radii measured from the piths to the surface of the wood varied considerably more in the same disk, as regards length, than the diameters measured in different directions.

It was evident that the shape of the average cross-sectional area was not in general elliptical. It thus appears that any method for measuring the cross-sectional area which is based on elliptical formula is not suitable. The method which gave the best result was that in which the cross-sectional area was taken as the average of the area of the circle calculated from the smallest diameter and that calculated from the diameter passing at right angles to it. This method also appeared to be the best for disks which deviated to quite a large degree from the circular form. The suitability of this method is increased by the fact that the relative error is only slightly dependent on the size of the disk.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4899, category Article
Matti Kärkkäinen. (1974). Näkökohta tyvi- ja latvaläpimitan keskiarvoon perustuvasta mäntypölkkyjen kuutioinnista. Silva Fennica vol. 8 no. 2 article id 4899. https://doi.org/10.14214/sf.a14743
English title: Note on the volume based on the mean of butt and top diameters of Scots pine bolts.
Original keywords: kuitupuu; mänty; puutavaranmittaus; kapeneminen; tyviläpimitta; latvaläpimitta; kiintotilavuus
English keywords: Pinus sylvestris; Scots pine; pulpwood; timber scaling; tapering; butt diameter; top diameter; volume determination
Abstract | View details | Full text in PDF | Author Info

In this paper the use of butt and top diameters of pulpwood bolts for volume determination is analysed. The study is based on the taper data of Scots pine (Pinus sylvestris L.) stems. According to the results, the use of the mean of butt and top diameters in the volume determination under Finnish condition causes a positive error in small stems. If the stems are so big that the butt portions of the stems can be used as saw logs, the remaining top bolts, used as pulpwood, are estimated to be smaller than they are in reality. Accordingly, there is a negative error.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4896, category Article
Matti Kärkkäinen. (1974). Keskusmuotoluvun perusteita tukkien ja kuitupuun mittauksessa. Silva Fennica vol. 8 no. 1 article id 4896. https://doi.org/10.14214/sf.a14740
English title: Foundations of middle form factor in the measurement of logs and pulpwood.
Original keywords: kuitupuu; tukkipuu; puutavaranmittaus; menetelmät; muotoluku; kiintomitta
English keywords: logs; form factor; pulpwood; methods; timber scaling; determination of volume
Abstract | View details | Full text in PDF | Author Info

In this literature review some error possibilities in the measurement of solid volume of logs and pulpwood are discussed. Although both underestimation and overestimation can occur for various reasons it seems likely that in the stereometric measurement method the real volume is underestimated, at least when Huber’s formula is applied, and the respective middle form factors are too low. Numerous results of empirical investigations are presented in the paper, too.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4806, category Article
Esko Leinonen, Pentti Rikkonen. (1969). Puutavaran kuorma- ja kuormaotantamittaus. Silva Fennica vol. 3 no. 4 article id 4806. https://doi.org/10.14214/sf.a14594
English title: Load and load sampling measurement of timber.
Original keywords: puutavara; puunkuljetus; puutavaranmittaus; kuormamittaus; otos
English keywords: timber scaling; load sampling; timber transportation; wood measurement; load measurement; measurement of roundwood
Abstract | View details | Full text in PDF | Author Info

Measurement of timber in a vehicle load or in a bundle is best performed at the mill where the measuring of large quantities can be mechanized and sampling is possible. Load measurement methods include calculation of the number of units, measurement of pile volume, weight scaling and determination of solid content in accordance with Archimedes principle by immersion in water. For some timber assortments, load measurement is sufficiently accurate and suitable unit of measure. The accuracy of load measurement can be increased or the result can be converted by sampling to a more appropriate unit of measure.

In load sampling measurement, a sample is taken from the population, and the desired more accurate measurement is made from the sample. The basic measurement for the whole population can be converted into the more accurate measuring unit by means of the ratio between it and the basic measure. Unit, pile and weight sampling can be used. The aim for pulpwood is to calculate the dry matter content without bark, which means that the amount of bark and the dry weight of wood must be determined by sampling.

The size of the sample depends on size of the population, variation of the ratio between the loads, and the accuracy required. As the quantity of wood to be measured decreases, sampling measurement will reduce the measuring costs by up to 80%. In addition, there is saving in costs by rationalization.

The PDF includes a summary in English.

  • Leinonen, E-mail: el@mm.unknown (email)
  • Rikkonen, E-mail: pr@mm.unknown
article id 4729, category Article
Puutavaranmittauskomitea. (1966). Puutavaranmittauskomitean mietintö : Osamietintö I. Silva Fennica no. 118 article id 4729. https://doi.org/10.14214/sf.a14287
English title: Report of timber scaling committee.
Original keywords: komiteanmietinnöt; puukauppa; puutavaranmittaus; puutavaranmittauslaki
English keywords: legislation; wood sales; timber sales; timber scaling; Timber Scaling Act
Abstract | View details | Full text in PDF | Author Info

A Timber Scaling Committee was appointed by the Government of Finland in 1959, commissioned with the regulations concerning the scaling of timber and to draw a proposal for their amendments. The commission suggest revision of the regulations in their entire extent. The largest alterations should be made in the act which incorporates the provisions concerning the actual technical methods of procedure in measuring. Thus, also amendments were also posed for the Timber Scaling Law and the law concerning the scaling of timber for the purpose of paying wages.

The inclusion of the setting of the grades and quantities are considered important, since most of the disagreements occurring in measuring are concerned with quality of the timber. Inside of the sphere of application of the law would also be settling of the problems of the quality, and the measuring procedure, also when measuring for the purpose of paying wages.

According to the bill, the necessary number of official scalers and scaling boards would be appointed. The duties of the present officers would be changed. In the boards would be presented sellers, buyers, employers and employees besides the chairman. The freedom of contract in the scaling of timber will be preserved from the present law.

The report includes a bill for the Timber scaling Act, a draft for the timber scaling act, and a draft for an act which includes the timber scaling rules.

The PDF includes a summary in English.

  • Puutavaranmittauskomitea, E-mail:

Category : Research article

article id 244, category Research article
Georg E. Kindermann, Ian McCallum, Steffen Fritz, Michael Obersteiner. (2008). A global forest growing stock, biomass and carbon map based on FAO statistics. Silva Fennica vol. 42 no. 3 article id 244. https://doi.org/10.14214/sf.244
Keywords: biomass map; downscaling; regression analysis
Abstract | View details | Full text in PDF | Author Info
Currently, information on forest biomass is available from a mixture of sources, including in-situ measurements, national forest inventories, administrative-level statistics, model outputs and regional satellite products. These data tend to be regional or national, based on different methodologies and not easily accessible. One of the few maps available is the Global Forest Resources Assessment (FRA) produced by the Food and Agriculture Organization of the United Nations (FAO 2005) which contains aggregated country-level information about the growing stock, biomass and carbon stock in forests for 229 countries and territories. This paper presents a technique to downscale the aggregated results of the FRA2005 from the country level to a half degree global spatial dataset containing forest growing stock; above/below-ground biomass, dead wood and total forest biomass; and above-ground, below-ground, dead wood, litter and soil carbon. In all cases, the number of countries providing data is incomplete. For those countries with missing data, values were estimated using regression equations based on a downscaling model. The downscaling method is derived using a relationship between net primary productivity (NPP) and biomass and the relationship between human impact and biomass assuming a decrease in biomass with an increased level of human activity. The results, presented here, represent one of the first attempts to produce a consistent global spatial database at half degree resolution containing forest growing stock, biomass and carbon stock values. All results from the methodology described in this paper are available online at www.iiasa.ac.at/Research/FOR/.
  • Kindermann, International Institute for Applied Systems Analysis, Laxenburg, Austria E-mail: kinder@iiasa.ac.at (email)
  • McCallum, International Institute for Applied Systems Analysis, Laxenburg, Austria E-mail: im@nn.at
  • Fritz, International Institute for Applied Systems Analysis, Laxenburg, Austria E-mail: sf@nn.at
  • Obersteiner, International Institute for Applied Systems Analysis, Laxenburg, Austria E-mail: mo@nn.at

Category : Review article

article id 552, category Review article
Timo Kuuluvainen. (2002). Natural variability of forests as a reference for restoring and managing biological diversity in boreal Fennoscandia. Silva Fennica vol. 36 no. 1 article id 552. https://doi.org/10.14214/sf.552
Keywords: biodiversity; ecosystem management; disturbance dynamics; succession; sustainable forestry; heterogeneity; hierarchy; scaling; spatiotemporal dynamics
Abstract | View details | Full text in PDF | Author Info
In Fennoscandia, use of the natural forest as a reference for restoration and management of forest biodiversity has been widely accepted. However, limited understanding of the structure and dynamics of the natural forest has hampered the applications of the natural variability approach. This is especially the case in areas, where the natural forests have almost totally vanished. This review was motivated by the idea that despite these difficulties the essential features of the natural forest can be reconstructed based on biological archives, historical documents, research done in adjacent natural areas, and modeling. First, a conceptual framework for analyzing the relationship between forest structure, dynamics and biodiversity is presented. Second, the current understanding of the structure and dynamics of natural forests at different spatiotemporal scales in boreal Fennoscandia is reviewed. Third, the implications of this knowledge, and gaps in knowledge, on research and on practical restoration and management methods aimed at forest biodiversity conservation are discussed. In conclusion, naturally dynamic forest landscapes are complex, multiscaled hierarchical systems. Current forest management methods create disturbance and successional dynamics that are strongly scale-limited when compared with the natural forest. To restore some of the essential characteristics of the natural forest’s multiscale heterogeneity, diversification of silvicultural and harvesting treatments, as guided by natural disturbance dynamics, is needed to produce more variation in disturbance severity, quality, extent, and repeatability.
  • Kuuluvainen, Department of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi (email)

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