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Impact factor 1.683
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Silva Fennica 1926-1997
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Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'statistics'.

Category: Research article

article id 155, category Research article
Minna Räty, Annika Kangas. (2010). Segmentation of model localization sub-areas by Getis statistics. Silva Fennica vol. 44 no. 2 article id 155. https://doi.org/10.14214/sf.155
Models for large areas (global models) are often biased in smaller sub-areas, even when the model is unbiased for the whole area. Localization of the global model removes the local bias, but the problem is to find homogenous sub-areas in which to localize the function. In this study, we used the eCognition Professional 4.0 (later versions called Definies Pro) segmentation process to segment the study area into homogeneous sub-areas with respect to residuals of the global model of the form height and/or local Getis statistics calculated for the residuals, i.e., Gi*-indices. The segmentation resulted in four different rasters: 1) residuals of the global model, 2) the local Gi*-index, and 3) residuals and the local Gi*-index weighted by the inverse of the variance, and 4) without weighting. The global model was then localized (re-fitted) for these sub-areas. The number of resulting sub-areas varied from 4 to 366. On average, the root mean squared errors (RMSEs) were 3.6% lower after localization than the global model RMSEs in sub-areas before localization. However, the localization actually increased the RMSE in some sub-areas, indicating the sub-area were not appropriate for local fitting. For 56% of the sub-areas, coordinates and distance from coastline were not statistically significant variables, in other words these areas were spatially homogenous. To compare the segmentations, we calculated an aggregate standard error of the RMSEs of the single sub-areas in the segmentation. The segmentations in which the local index was present had slightly lower standard errors than segmentations based on residuals.
  • Räty, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland ORCID ID:E-mail: minna.s.raty@helsinki.fi (email)
  • Kangas, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland ORCID ID:E-mail:
article id 321, category Research article
Jori Uusitalo, Anne Puustelli, Veli-Pekka Kivinen, Tapio Nummi, Bikas K. Sinha. (2006). Bayesian estimation of diameter distribution during harvesting. Silva Fennica vol. 40 no. 4 article id 321. https://doi.org/10.14214/sf.321
This research aims to combine two different data sets with Bayesian statistics in order to predict the diameter distribution of trees at harvest. The parameters of prior distribution are derived from the forest management plans supplemented by additional ocular information. We derive the parameters for the sample data from the first trees harvested, and then create the posterior distribution within the Bayesian framework. We apply the standard normal distribution to construct diameter (dbh) distributions, although many other theoretical distributions have been proved better with dbh data available. The methodology developed is then tested on nine mature spruce (Picea abies) dominated stands, on which the normal distribution seems to work well in mature spruce stands. The tests indicate that prediction of diameter distribution for the whole stand based on the first trees harvested is not wise, since it tends to give inaccurate predictions. Combining the first trees harvested with prior information seems to increase the reliability of predictions.
  • Uusitalo, The Finnish Forest Research Institute, Parkano unit, FI-39700 Parkano, Finland ORCID ID:E-mail: jori.uusitalo@metla.fi (email)
  • Puustelli, University of Tampere, Department of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland ORCID ID:E-mail:
  • Kivinen, University of Helsinki, Department of Forest Resource Management, Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail:
  • Nummi, University of Tampere, Department of Mathematics, Statistics and Philosophy, FI-33014 University of Tampere, Finland ORCID ID:E-mail:
  • Sinha, Stat-Math Division, Indian Statistical Institute, 203 B.T. Road, Kolkata - 700 108, India ORCID ID:E-mail:
article id 333, category Research article
Lauri Mehtätalo, Matti Maltamo, Annika Kangas. (2006). The use of quantile trees in the prediction of the diameter distribution of a stand. Silva Fennica vol. 40 no. 3 article id 333. https://doi.org/10.14214/sf.333
This study deals with the prediction of the basal area diameter distribution of a stand without using a complete sample of diameters from the target stand. Traditionally, this problem has been solved by either the parameter recovery method or the parameter prediction method. This study uses the parameter prediction method and the percentile based diameter distribution with a recent development that makes it possible to improve these predictions by using sample order statistics. A sample order statistic is a tree whose diameter and rank at the plot are known, and is referred to in this paper as a quantile tree. This study tested 13 different strategies for selection of the quantile trees from among the trees of horizontal point sample plots, and compared them with respect to RMSE and the bias of four criterion variables in a dataset of 512 stands. The sample minimum was found to be the most promising alternative with respect to RMSE, even though it introduced a rather large amount of bias in the criterion variables. Other good and less biased alternatives are the second and third smallest trees and the tree closest to the plot centre. The use of minimum is recommended for practical inventories because its rank is probably easiest to determine correctly in the field.
  • Mehtätalo, Yale School of Forestry and Environmental Studies, 205 Prospect Street, New Haven, CT 06511, USA ORCID ID:E-mail: lauri.mehtatalo@metla.fi (email)
  • Maltamo, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Kangas, University of Helsinki, Department of Forest Resources Management, P.O.Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail:

Category: Article

article id 7488, category Article
Viljo Holopainen. (1959). The concept of a roundwood price level and its determination in forestry. Acta Forestalia Fennica vol. 68 no. 6 article id 7488. https://doi.org/10.14214/aff.7488

Roundwood statistics are essential in a country such as Finland, where the roundwood market costitutes one of the most important internal markets. Determining the price level of roundwood can, however, be problematic due to the difficulty of the empirical determination. The main difficulties are the many timber assortments, quality differcences within a timber assortment, large variation of local prices due to variations in demand and harvesting conditions and in sales methods. The article discusses these problems from the perspective of composing a roundwood statistics for different timber assortments that would allow local and temporal comparison of the prices. It seems impossible to compose price statistics that could eliminate totally the variation in the material, transport conditions and demand fluctuations caused by technical development. However, one can suffice to a compromise that would eliminate the major disturbances and take into account other factors that are not related with market when studying the price series. In addition, the paper discusses methods for calculation of price indices.

The PDF includes a summary in Finnish.

  • Holopainen, ORCID ID:E-mail:
article id 7445, category Article
Jaakko Vöry. (1954). Puutavaran valmistuksen keskityötulosten määrittäminen tilastoteitse. Acta Forestalia Fennica vol. 61 no. 33 article id 7445. https://doi.org/10.14214/aff.7445
English title: Statistical determination of the average work performance in the preparation of timber.

Work studies conducted in Finland and Sweden on forest work have shown that the performance of different workers or even of a same worker vary greatly, although external conditions such as the size and other properties of the trees, weather etc. are similar. It has been decided in the Northern Countries that as it is impossible to assess the working speed of a man, it is not possible to find out the average work performances, not even from long term time studies. The only way is to collect performance statistics.

Metsäteho (Forest Work Studies Section of the Central Association of Finnish Woodworking Industries) has collected since 1946 statistics on the working sites of forest industry companies in different parts of Finland on the preparation on timber. To make it comparable the material has been converted to uniform values by using the ratios given by the work time studies of various forest jobs conducted by Metsäteho. The ratios are necessary in trying to determine average performances by statistical means. The actual length of time each man is at work on different days and the actual number of days is needed, because in Finland the workers can themselves decide fairly freely the length of a working day. In forest work, wages are paid for the quantity prepared, not for time. The statistics collected by Metsäteho include information on the length of the working days, and conditions in each forest, such as the size of the trees, form of stem, branchiness, bark thickness, terrain, density of the forest, weather conditions etc.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in English.

  • Vöry, ORCID ID:E-mail:
article id 5242, category Article
Suomen tilastoseura, Finnish Society of Forest Science. (1985). Metsien inventoinnin tilastolliset menetelmät. Silva Fennica vol. 19 no. 3 article id 5242. https://doi.org/10.14214/sf.a15421
English title: Statistical methods in forest inventory.

At a joint meeting of the Finnish Statistical Society and the Society of Forestry in Finland on 17.10.1984, papers were presented on the history and mathematical foundations of statistical methods used in forest inventory in Finland. The advantages and applicability of Bayresian methods and methods of spatial statistics were also discussed. In two papers, forest inventories were examined as part of a forest information system and the information demands of the user were discussed.

This article includes eight presentation held in the meeting. The papers have each a summary in English.

  • Suomen tilastoseura, ORCID ID:E-mail:
  • Finnish Society of Forest Science, ORCID ID:E-mail:
article id 7032, category Article
August Renvall. (1919). Program för utredningen af industrins jordförfärf. Acta Forestalia Fennica vol. 13 no. 1 article id 7032. https://doi.org/10.14214/aff.7032
English title: Statistical studies on land purchase of forest companies in Finland I.

The article includes a program for an investigation concerning land purchases by the forestry companies in Finland, requested by the Finnish Forest Association in 1917. The paper draws detailed principles for collecting a comprehensive, accurate and objective information of land purchases of the industry, as well as land holdings, farms and forest lands owned by the companies. Finally, it gives suggestions on how to correct the observed problems in the land purchase, and how to balance the conflicts of interests between the different branches.  

The PDF includes a summary in German. 

  • Renvall, ORCID ID:E-mail:
article id 4452, category Article
Eino Saari. (1929). Ehdotus puun käyttöä osottavan jatkuvan tilaston järjestämisestä Suomeen. Silva Fennica no. 11 article id 4452. https://doi.org/10.14214/sf.a8985
English title: A proposal to introduce permanent statistics of wood consumption in Finland.

The Forest Research Institute made an investigation on the wood consumption in Finland in 1927. This work brought up a need to organize continuous collection of statistics of wood consumption. Three kinds of existing statistics can be used: statistics of wood consumption, statistic of the fellings, and statistics of transport of wood.

Statistics on wood consumption, such as the fuel used by the industry and State railways are collected annually. The fellings in state forests are published annually, and also the wood manufacturing companies publish statistics of their forests. Furthermore, all fellings on sale, and use of own wood in wood manufacturing industry have to be reported to the forestry committees. These statistics are published annually. Railroads and floating are the main means of long distance transport of wood. These statistics give additional information of wood consumption. Further studies are needed to combine and standardize the statistics collected from different sources.

The PDF includes a summary in English.

  • Saari, ORCID ID:E-mail:
article id 4650, category Article
Metsätilastokomitea. (1956). Metsätilastokomitean mietintö. Silva Fennica no. 89 article id 4650. https://doi.org/10.14214/sf.a9112
English title: Report on Committee on Forest Statistics.

The ministry of agriculture appointed a committee to prepare a proposal for the reorganization of Finnish forest statistics. The committee suggests that the forest statistics will be prepared by forest district board areas. National forest surveys and national wood consumption surveys should be carried out at intervals of 10-15 years by Forest Research Institute.

Felling and price statistics for private forests should be prepared by using a sampling method described in the report. The statistics of total commercial roundwood felling will be obtained by adding to the result the annual felling from state and company forests. Also, wage and employment statistics in forestry will be prepared by a sampling method.

Statistics concerning timber transportation should be improved, and finally, a central organ for forest statistics should be established within the Forest Research Institute to collect and develop forest statistics. The statistics should be published as an annual yearbook. To ensure co-operation between the authorities, a special sub-committee should be appointed to collaborate with the permanent committee of statistics in Finland.

  • Metsätilastokomitea, ORCID ID:E-mail:
article id 4650, category Article
Metsätilastokomitea. (1956). Metsätilastokomitean mietintö. Silva Fennica no. 89 article id 4650. https://doi.org/10.14214/sf.a9112
English title: Report on Committee on Forest Statistics.

The ministry of agriculture appointed a committee to prepare a proposal for the reorganization of Finnish forest statistics. The committee suggests that the forest statistics will be prepared by forest district board areas. National forest surveys and national wood consumption surveys should be carried out at intervals of 10-15 years by Forest Research Institute.

Felling and price statistics for private forests should be prepared by using a sampling method described in the report. The statistics of total commercial roundwood felling will be obtained by adding to the result the annual felling from state and company forests. Also, wage and employment statistics in forestry will be prepared by a sampling method.

Statistics concerning timber transportation should be improved, and finally, a central organ for forest statistics should be established within the Forest Research Institute to collect and develop forest statistics. The statistics should be published as an annual yearbook. To ensure co-operation between the authorities, a special sub-committee should be appointed to collaborate with the permanent committee of statistics in Finland.

  • Metsätilastokomitea, ORCID ID:E-mail:
article id 4622, category Article
O. O. Tirkkonen. (1952). Suomen metsäojitus 1900-luvun alkupuoliskolla. Silva Fennica no. 72 article id 4622. https://doi.org/10.14214/sf.a9094
English title: Peatland drainage in Finland in the first half of 20h century.

According to the second National Forest Survey, peatlands covered before the World War II 11,156,000 hectares, 32% of the land area of Finland. The early drainage of peatlands in 1700th century had aimed at preventing frost and increasing area of agricultural land. The experiences proved that drainage of wet forests was lucrative also in the point of view of forestry. The drainage of state-owned forest lands was promoted by the Crown Forest Committee in its report in 1900. The systematic drainage work in state lands begun in 1909. In the end of 1920s 500-700 km of ditches was dug annually.

The drainage of private lands begun after 1928, when forestry promotion work in private forests begun. By the end of 1950, 4,815 forest drainage projects had been approved by the Forest Service in the private lands. In addition, 286,000 ha of peatlands was drained on work organized by the central forest associations in 1930-1950, and 239,272 ha by timber companies in 1902-1950. The drained area totalled 755,892 ha. The area of drainable and drained peatland was estimated to be 4.4 million ha.

The article includes an abstract in English.

  • Tirkkonen, ORCID ID:E-mail:
article id 4619, category Article
P. Ennevaara. (1951). Tilastoista ja niiden käyttömahdollisuuksista. Silva Fennica no. 69 article id 4619. https://doi.org/10.14214/sf.a14015
English title: Use of statistics in forestry.

Silva Fennica Issue 69 includes presentations held in 1948-1950 in the fourth professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation introduces different forestry related statistics and discusses the potential use of statistics on the point of view of state forestry.

  • Ennevaara, ORCID ID:E-mail:
article id 4563, category Article
Paavo Aro. (1939). Hakkaustapatilasto. Silva Fennica no. 52 article id 4563. https://doi.org/10.14214/sf.a13970
English title: Statistics of felling methods.

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes the use and purpose of statistics about different felling methods compiled in Forest Service.

  • Aro, ORCID ID:E-mail:
article id 4494, category Article
Eino Saari. (1937). Metsätaloudelliset tilastot. Silva Fennica no. 39 article id 4494. https://doi.org/10.14214/sf.a13904
English title: Forestry statistics.

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation lists statistics available on forestry.

  • Saari, ORCID ID:E-mail:
article id 4494, category Article
Eino Saari. (1937). Metsätaloudelliset tilastot. Silva Fennica no. 39 article id 4494. https://doi.org/10.14214/sf.a13904
English title: Forestry statistics.

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation lists statistics available on forestry.

  • Saari, ORCID ID:E-mail:

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