Articles containing the keyword 'measurement'

The Värriö environmental measurement station has been designed and constructed during 1991 and 1992. The measurement system consists of measurement units for gases (sulphur dioxide, ozone, carbon dioxide), particles, photosynthesis and irradiation. A meteorological station is also included. The preliminary measurement period was started on August, 1991. During the first year (1991–1992) some parts of the system were redeveloped and rebuilt. Full, continuous measurement started in August 1992. The system has been working quite reliably, with good accuracy. The preliminary results show that pollution episodes are observed when the wind direction is from Monchegorsk or Nikel, the main emission sources in Kola Peninsula.

• Hari, E-mail: ph@mm.unknown
• Aalto, E-mail: pa@mm.unknown
• Hämeri, E-mail: kh@mm.unknown
• Kulmala, E-mail: mk@mm.unknown
• Lahti, E-mail: tl@mm.unknown
• Luoma, E-mail: sl@mm.unknown
• Palva, E-mail: lp@mm.unknown
• Pohja, E-mail: tp@mm.unknown
• Pulliainen, E-mail: ep@mm.unknown
• Siivola, E-mail: es@mm.unknown
• Vesala, E-mail: tv@mm.unknown

A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of fabric might also have an influence. Embankment thickness and peat depth can be measured on the radiogram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning.

The PDF includes a summary in Finnish.

• Saarilahti, E-mail: ms@mm.unknown

Good correlation between radar reflection depth when using a FM-CW radar during winter and bearing capacity measurements during spring breakup was found. Therefore, it might be possible to evaluate the bearing capacity of forest roads using the radar sounding technique.

The PDF includes a summary in Finnish.

• Saarilahti, E-mail: ms@mm.unknown

A method to determine sulphur as sulphate has been applied to search for surface concentration of sulphate sulphur on needle samples. The method is based on reducing sulphates as volatile hydrogen sulphide gas by using hydriodic acid. The hydrogen sulphide gas is swept with nitrogen into an absorbent solution. Sulphide ion concentration in solution is then measured using ion selective electrodes.

The method was applied on one to four years old needle samples collected from Scots pine (Pinus sylvestris L.) at 0.9 to 15.9 km distances from a 1,064 MW coal-fired power plant in Southern Finland. Surface sulphate values found in the samples closer than 4 km to the power plant were 50 to 100% higher than a nearly constant background level. No significant variation of values with needle age was found. The advantages of the method compares to other methods for sulphur determination are speed, reasonable sensitivity and low detection limit.

• Hautojärvi, E-mail: ah@mm.unknown
• Ahonen, E-mail: sa@mm.unknown
• Erkinjuntti, E-mail: re@mm.unknown
• Katainen, E-mail: hk@mm.unknown
• Lappalainen, E-mail: tl@mm.unknown
• Raunemaa, E-mail: tr@mm.unknown

The use and problems of the sucrose inversion method for the study of forest humus and soil are discussed. The method is based on the temperature dependence of sucrose inversion, changes in rotation angle being determined with a circle polarimeter. Average temperatures and thermal sums for forest humus in different forests in Finland were measured, using this method, for a period of ca. 100 days. The results are not considered definitive but are regarded rather as examples. Average temperatures were somewhat higher in the humus of dry and poor heath forests than in that of moist and herb-rich forests, with exceptions that could be explicable by topographic position.

The PDF includes a summary in English.

• Ohenoja, E-mail: eo@mm.unknown
• Pohjola, E-mail: lp@mm.unknown

A system for measuring the net photosynthesis, transpiration and environmental factors within the canopy and ground cover vegetation is described. The system operates continuously throughout the growing season in a young Scots pine (Pinus sylvestris L.) stand. A data-logging unit controls the system and carries out the measurements on the readings of the sensors of photosynthesis, transpiration, light intensity outside the canopy, light climate inside the assimilation chambers, and dry and wet temperatures from selected points. These measurements are shown digitally and automatically punched onto paper tape.

The PDF includes a summary in Finnish.

• Hari, E-mail: ph@mm.unknown
• Kanninen, E-mail: mk@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Luukkanen, E-mail: ol@mm.unknown
• Pelkonen, E-mail: pp@mm.unknown
• Salminen, E-mail: rs@mm.unknown
• Smolander, E-mail: hs@mm.unknown

The physical methods currently available for measuring the internal decay of living trees is examined in this study. Although this is mainly a review, it can be concluded that some measurements shed more light on the problem. Examination of ultrasonic methods reveals that the coupling of ultrasonic energy from the transducer to the tree is not efficient. Both impulse and ultrasonic testing work best with decayed and hollow trees. The electrical resistance measurements of stumps gave resistance values for sound wood 300–400 kΩ, for decayed and discoloured wood about 12 kΩ and for cambium about 12 kΩ. The neutron activation gives good results, and in particular it reveals nicely the increasing concentration of potassium in decayed wood. The internal decay of living trees was not examined.

The PDF includes a summary in Finnish.

• Jartti, E-mail: pj@mm.unknown

The aim of the study was to find out the technical and economical applicability of seismic survey methods of sub-surface earth investigations in forest road planning. Two seismographs, SOIL-TEST MD 1 and BISON 1570, were tested in studyin 31 cuts and 3 gravel areas. The devices proved to be usable in field conditions. Sounding one spot costs about 75 Fmk and methods’ rentability is greatly based on the ration between expected and unexpected events, which depends on the areal geology. It is profitable to purchase the device especially if digging out of unexpected bedrock causes high costs.

The PDF includes a summary in English.

• Saarilahti, E-mail: ms@mm.unknown

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
• Rikkonen, E-mail: pr@mm.unknown

The present study gives an account of the dependence prevailing between the actual volume of timber crops, and, on one hand, the sum of cylindrical volume of individual trees, and on the other hand, the utilization per cent. This dependence is rectlinear if the volumes in question are calculated on a running-foot basis. The cylindrical volume of individual trees was calculated on the basis of cross-section area at breast height and the height of the trees. On the basis of the results, it seems that it is possible to simplify timber measurement.

The PDF includes a summary in English.

• Nisula, E-mail: pn@mm.unknown

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 Timber Measurement Act, adopted in 1938, and its application.

• Mecklin, E-mail: am@mm.unknown

The study examines the accuracy of volume tables for top measurement of pulpwood boles, and that of top measurement in general in Northern Finland. In this method only top diameter and length of the boles are measured, and the volume is obtained from volume tables. The boles have previously been measured in the middle of the bole, but the method is very time consuming in practice.

The result indicates that the form of both Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) varies greatly. A pulpwood parcel, however, contains both rapidly and gently tapering logs, and the average form differences are much smaller. The difference between the real volume and the volume obtained from the volume tables is generally less than 12% and for more than third of the stock less than 4%.

Pine boles from private forests have been somewhat more and spruce boles less rapidly tapering than boles cut from state forests. The significance of the differences is not clear. Also, the boles in the northern part of the investigation area taper more sharply than those in the southern part.
It is concluded that the accuracy of the top measurement should be improved, but this is only theoretically possible by means of special tables and correction coefficients.

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

• Heiskanen, E-mail: vh@mm.unknown

Exported wood is measured at the port in Finland by certified measurers. Wood is paid according to these measuring certificates. However, in many cases the buyer measures the wood again in the country of destination, and gets smaller amounts. This sometimes causes awkward situations.

To examine the phenomenon one lot of pulpwood was measured both in Finland and in the destination country Germany. Several differences were found for the amounts of wood, and the author discussed the possible reasons for these differences.

However, because of the possible scattering in the measurements, several reductions are always made to the measurements. Hence it was proved that the buyer got the amount of wood they paid for. It is clear that the current practices and tools used to measure the amount of wood do not allow for any more accurate measures.     

The PDF contains a summary in Finnish. 

• Aro, E-mail: pa@mm.unknown

• Peltoniemi, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mikko.peltoniemi@metla.fi
• Heikkinen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jh@nn.fi
• Mäkipää, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: raisa.makipaa@metla.fi

• Stenman, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland https://orcid.org/0000-0003-1176-7840 E-mail: virpi.stenman@helsinki.fi
• Kangas, Natural Resources Institute Finland (Luke), Bio­economy and Environment, P.O. Box 68, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-8637-5668 E-mail: annika.kangas@luke.fi
• Holopainen, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: markus.holopainen@helsinki.fi

Bilberry (Vaccinium myrtillus L.) and lingonberry (V. vitis-idaea L.) can be a part of healthy diet and are important for many animals. Two approaches are described to assessing their vegetation cover and berry yield via national forest inventory (NFI) observations. The aim was to provide estimates and predictions of the abundance and yield of the species at regional and national levels in Finland and Sweden. In Finland, the model-based predictions are used in evaluating the impacts of cutting intensity on forest berries needed in forest-related decision making. In Sweden, seasonal inventory-based estimates are used to evaluate the annual national and regional berry yields, and in a forecasting system aimed at large public and berry enterprises. Based on the NFI sample plots measured between 2014 and 2018, the total annual yields are estimated to be 208 Mkg of bilberry and 246 Mkg of lingonberry on productive forest land (increment at least 1 m³ ha^–1 year^–1) in Finland, and 336 and 382 Mkg respectively in Sweden (average of NFI inventories in 2015–2019). The predicted development of berry yields is related to the intensity of cuttings in alternative forest management scenarios: lower removals favoured bilberry, and higher removals lingonberry. The model-based method describes the effects of stand development and management on berry yields, whereas the inventory-based method can calibrate seasonal estimates through field observations. In providing spatially and timely more accurate information concerning seasonal berry yields, an assessment of berry yields should involve the elements of both inventory-based and model-based approaches described in this study.

• Miina, Natural Resources Institute Finland (Luke), Yliopistokatu 6 B, FI-80100 Joensuu, Finland https://orcid.org/0000-0002-8639-4383 E-mail: jari.miina@luke.fi
• Bohlin, Swedish University of Agricultural sciences (SLU), Department of Forest Resource Management, Skogsmarksgränd, S-901 83 Umeå, Sweden E-mail: inka.bohlin@slu.se
• Lind, Swedish University of Agricultural sciences (SLU), Department of Forest Resource Management, Skogsmarksgränd, S-901 83 Umeå, Sweden E-mail: torgny.lind@slu.se
• Dahlgren, Swedish University of Agricultural sciences (SLU), Department of Forest Resource Management, Skogsmarksgränd, S-901 83 Umeå, Sweden E-mail: jonas.dahlgren@slu.se
• Härkönen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: kari.harkonen@luke.fi
• Packalen, Natural Resources Institute Finland (Luke), Yliopistokatu 6 B, FI-80100 Joensuu, Finland; Ministry of Agriculture and Forestry of Finland, P.O. Box 30, FI-00023 Government, Finland E-mail: tuula.packalen@mmm.fi
• Tolvanen, Natural Resources Institute Finland (Luke), Paavo Havaksentie 3, FI-90014 University of Oulu, Finland E-mail: anne.tolvanen@luke.fi

Harvesting residues collected from the final cuttings of boreal forests are an important source of solid biofuel for energy production in Finland and Sweden. In the Finnish supply chain, the measurement of residues is performed by scales integrated in forwarders. The mass of residues is converted to volume by conversion factors. In this study, weather based models for defining the moisture content of residues were developed and validated. Models were also compared with the currently used fixed tables of conversion factors. The change of the moisture content of residues is complex, and an exact estimation was challenging. However, the model predicting moisture change for three hour periods was found to be the most accurate. The main improvement compared to fixed tables was the lack of a systematic error. It can be assumed that weather based models will give more reliable estimates for the moisture in varying climate conditions and the further development of models should be focused on obtaining more appropriate data from varying drying conditions in different geographical and microclimatological locations.

• Lindblad, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: jari.lindblad@luke.fi
• Routa, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: johanna.routa@luke.fi
• Ruotsalainen, Finnish Meteorological Institute, Aviation and Military Weather Services, P.O. Box 1627, FI-70211 Kuopio, Finland E-mail: johanna.ruotsalainen@fmi.fi
• Kolström, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: marja.kolstrom@uef.fi
• Isokangas, University of Oulu, Control Engineering, P.O. Box 8000, FI-90014 University of Oulu, Finland E-mail: ari.isokangas@oulu.fi
• Sikanen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: lauri.sikanen@luke.fi

• Kangas, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: annika.kangas@helsinki.fi
• Mehtätalo, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland E-mail: lm@nn.fi
• Mäkinen, Simosol Oy, Riihimäki, Finland E-mail: am@nn.fi
• Vanhatalo, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: kv@nn.fi

• Kitahara, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, 6-10-1 Hakozaki, Higashiku, Fukuoka 812-8581, Japan E-mail: bunsho@ffpri.affrc.go.jp
• Mizoue, Faculty of Agriculture, Kyushu University, Fukuoka, Japan E-mail: nm@nn.jp
• Yoshida, Faculty of Agriculture, Kyushu University, Fukuoka, Japan E-mail: sy@nn.jp

• Haara, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: arto.haara@joensuu.fi
• Leskinen, Finnish Environment Institute, Research Programme for Production and Consumption, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: pl@nn.fi

• Peuhkurinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jp@nn.fi
• Maltamo, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mm@nn.fi
• Malinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jm@nn.fi

• Haara, Finnish Forest Research Institute, Joensuu Research Centre, P.O.Box 68, FIN-80101 Joensuu, Finland E-mail: arto.haara@metla.fi

• Kangas, University of Helsinki, Dept. of Forest Resources Management, P.O. Box 27, 00014 University of Helsinki, Finland E-mail: annika.kangas@helsinki.fi
• Maltamo, University of Joensuu, Faculty of Forestry, P.O. Box 111, 80101 Joensuu, Finland E-mail: mm@nn.fi

• Eskelinen, Lappeenranta University of Technology, Department of Electrical Engineering, P.O. Box 20, FIN-53851 Lappeenranta, Finland E-mail: ari.eskelinen@pp.inet.fi
• Eskelinen, Lappeenranta University of Technology, Department of Electrical Engineering, P.O. Box 20, FIN-53851 Lappeenranta, Finland E-mail: he@nn.fi

• Aalto, Department of Physics, P.O. Box 9, FIN-00014 University of Helsinki, Finland E-mail: tuula.aalto@helsinki.fi

• Palva, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: lauri.palva@hut.fi
• Garam, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: eg@nn.fi
• Palmroth, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: sp@nn.fi
• Sepponen, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: rs@nn.fi
• Hari, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: ph@nn.fi

• de Miguel-Díez, Eberswalde University for Sustainable Development, Department of Forest Utilization and Timber Markets, Eberswalde, Germany; University of Freiburg, Chair of Forest Operations, Freiburg, Germany https://orcid.org/0000-0002-3800-7449 E-mail: felipe.diez@hnee.de
• Purfürst, University of Freiburg, Chair of Forest Operations, Freiburg, Germany https://orcid.org/0000-0001-9661-0193 E-mail: thomas.purfuerst@foresteng.uni-freiburg.de
• Acuna, University of the Sunshine Coast, Forest Research Institute, Sunshine Coast, Queensland, Australia E-mail: macuna@usc.edu.au
• Tolosana-Esteban, Universidad Politécnica de Madrid, E.T.S.I. Montes, Forestal y del Medio Natural, Madrid, Spain https://orcid.org/0000-0003-2561-0342 E-mail: eduardo.tolosana@upm.es
• Cremer, Eberswalde University for Sustainable Development, Department of Forest Utilization and Timber Markets, Eberswalde, Germany https://orcid.org/0000-0001-7866-944X E-mail: Tobias.Cremer@hnee.de

The objective of the study is to derive a method by which one can analyze how the probability of damage made by pine weevils on seedlings treated with insecticides depends on the probability of damage on untreated control seedlings, called feeding pressure. Because the probabilities vary from stand to stand and from block to block, the analysis is done using a generalized linear mixed model. The dependency of probability of damage on the feeding pressure cannot be properly analyzed using observed relative frequency of damage of control seedlings as a covariate, but it can be analyzed using a bivariate model. One equation describes damage of control seedlings and another equation damage of treated seedlings. The random stand and block effects of different equations are correlated. For a given probability of stand level control seedling damage, the random stand effect for control seedlings can be computed using a link function, then random stand effects for treated seedlings can be predicted using the best linear predictor from the random effect for control seedlings. Using an inverse link the prediction can again be presented in the probability scale which is of interest to the user. Using these three steps the probability of damage of treated seedlings can be predicted from the control damage probability. The probability of damage of treated seedlings can also be predicted from the observed relative frequency of damaged control seedlings using simulation. The complementary log-log link was used for control seedlings and the log-log link for treated seedlings.

• Lappi, Natural Resources Institute Finland (Luke), Economics and society, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: juha.lappi@luke.fi
• Luoranen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: jaana.luoranen@luke.fi