Feasibility of Excavator-Based Harvester in Thinnings of Peatland Forests

In the next twenty years in Finland, annual cuttings on peatland forests are foreseen to increase by up to 30 % of the total cuttings. Cost effective harvesting methods on low yield peatland forests coupled with low ground bearing capacity are required. One solution to improve the feasibility of harvesting could be excavators tailored for forestry use and equipped with a harvesting head. In the study, cost competitiveness and productivity of the excavator-based harvester were investigated. The cost analysis focused on operating hours of harvester use, shift arrangements and purchase prices for the base machine and harvesting equipment when the base machine was used partly as a harvester and an excavator. Results were compared to conventional wheeled harvesters. If the base machine is used more than 3 working months as a harvester in addition to normal (6-8 months) excavator work, the harvesting method would be cost competitive compared to purpose-built harvesters (if 1½ and 2 shift arrangements were used). The 25 % increase of the base machine's and harvester equipments' purchasing costs did not eliminate the cost competitiveness of harvesting, when harvesting was carried out in 1 ½ shifts for at least 4 months. It would be feasible and profitable to invest in harvesting equipment for the excavator and therefore diminish the winter lay-days of the base machine by utilizing it in logging operations. Conditions on peatland sites mean that during the winter time the use of the excavator-based harvester is ideal, when the utilisation of all logging machines is at its highest

Validation of Prediction Models for Estimating the Moisture Content of Small Diameter Stem Wood

Moisture is the most important factor influencing the quality and calorific value of fuel wood. Drying models for estimating the optimal storage time based on average moisture change in fuel wood stacks stored outdoors have been developed for different stem wood piles. Models are an easy option for making an estimate of the moisture content of an energy wood pile if compared with sampling and measuring the moisture of samples. In this study, stem wood models were validated against data from forest companies. Fourteen reference piles of covered pine stem wood and 8 piles of uncovered pine stem wood were studied. The results of the validation are promising. The difference between the measured and modelled moisture was on average only 0.3% with covered piles and 2.5% with uncovered piles. The models presented can be implemented in every location in Finland, because the Finnish Meteorological Institute has a database for interpolated meteorological observations covering the whole country in a 10 km x 10 km grid. For international use, model parameters need to be estimated case by case, but it should also be possible to implement the approach itself worldwide

Atlas of the forest sector in Ukraine with the focus on wood fuels

Layout: Anne Siika, MetlaThis is a review of the current situation of the forest sector in Ukraine by considering a collection of maps. The cartographic information is grouped in the following way: forest resources, silviculture, wood harvesting, production and the most important producers of wood-based products, forest education and research and the potential of wood energy. This review serves the information needs ofdifferent stakeholders and of those interested in the forest sector in Ukraine

Effective biomass handling - predicting models & fast track supply

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Pienpuuhakkeen kustannustekijät ja toimituslogistiikka

Raportin taitto: Maija HeinoHankkeessa kehitettiin VMI:n koeala- ja monilähdeinventointiaineistoon sekä metsäyhtiöiden leimikkotietoihin perustuva nuorten metsien energiapuun kertymä- ja korjuukustannusten laskentamenetelmä. Kertymälaskelmissa hankinta-alueen säde oli 100 km tieverkkoa pitkin ja hankinta-alueet sijaitsivat Joensuun, Kouvolan, Valkeakosken Vaasan, Jyväskylän, Rovaniemen ja Kajaanin ympäristössä. Pienpuun saatavuudelle määritettiin viisi eri tasoa ekologis-taloudellisilla rajoitteilla. Laskenta-alueista Kouvolan ympäristössä pienpuun kertymä oli suurin ja Vaasan ympäristössä pienin. Vaasan ympäristössä kertymä 100 kilometrin säteellä oli eri kertymärajoitteilla 50 000 210 000 m3 vuodessa ja Kouvolan alueella 230 000 790 000 m3 vuodessa. Joensuun, Jyväskylän ja Kajaanin ympäristössä kertymät olivat 120 000 500 000 m3 vuodessa. Kertymälaskelmissa käytetyt rajoitteet vaikuttivat energiapuukertymän ohella puulajisuhteisiin. Kasvupaikan viljavuudelle asetetut minimirajoitteet vähensivät männyn osuutta ja lisäsivät koivun ja muiden lehtipuiden osuutta kokonaiskertymästä. Erot miestyönä tai koneella tehdyn pienpuun kaato-kasauksen kustannusten välillä ovat pienet, mutta kun huomioidaan metsäkuljetuksen tehostuminen koneellisen kaadon jäljiltä, on koneellinen korjuu miestyötä edullisempaa. Käyttöpaikkahintoja tarkasteltaessa ero kalleimman ja halvimman alueen välillä oli 15 %. Valkeakoskella ja Kouvolassa oli halvimmat käyttöpaikkahinnat. Seuraavaksi edullisimmat alueet olivat Jyväskylä, Joensuu ja Kajaani. Rovaniemellä oli korkein käyttöpaikkahinta ja Vaasassa toiseksi korkein. Koneelliseen kaato-kasaukseen ja kokopuun käyttöpaikkahaketukseen perustuva korjuuketju oli menetelmävertailussa edullisin kokopuuhakkeen tuotantomenetelmä. Pienpuulle maksettavat ns. Kemera-tuet parantavat pienpuuhakkeen kilpailukykyä hakkuutähdehakkeeseen verrattuna. Ilman tukia pienpuu ei pärjää hintavertailussa hakkuutähdehakkeen kanssa. Pienpuuhakkeen ero hakkuutähdehakkeen kustannuksiin syntyy kaato-kasausvaiheessa, joka maksaa 12 15 e/m3. Siksi toiminnan tehostaminen tulisi kohdistua juuri tähän vaiheeseen. Muiden kustannustekijöiden osalta pienpuuhake on kilpailukykyistä hakkuutähteeseen verrattuna

Pre-Feasibility Study of Carbon Sequestration Potential of Land Clearing Stumps Buried Underground

Stump harvesting for energy has decreased in Finland, and many heat and power plants no longer accept stumps in their fuel portfolio due to fuel quality problems. However Finland is a forested country, and land clearing stumps need to be extracted, e.g. in infrastructure construction projects. If stumps cannot be used for energy production, they are dumped in landfills, where they start to decay and release CO2 into the atmosphere. One option to avoid CO2 emissions would be the burying of stumps underground so that the decaying process of wood would be inhibited in anaerobic conditions. The aim of this study was to define the carbon sequestration potential of stump burying logistics and calculate their CO2-eq emissions to compare them with the emissions of decaying stumps in piles. The analysis was performed as a spreadsheet-based system analysis at a worksite level as a function of time and size of extracted stumps. As a result of the analysis, the emission effiency of the logistics chain based on stumps stored below the ground was good. The net carbon stock varied between 743.7 and 775.0 kg CO2-eq/m3 as a function of stump diameter, when the emissions of the stump burying logistics chain were 49.0 and 17.7 kg CO2-eq/m3 respectively. In the case of a Finnish municipality with an annual accumulation of 1000 m3 of land clearing stumps, the carbon sequestration potential of stumps buried underground is equivalent to the emissions of between 280,000 and 290,000 liters of diesel fuel consumption, depending on the diameter of the extracted stumps and the diesel fuel emission factors for different engine and diesel fuel types

Performance of an Innovative Bio-Based Wood Chip Storage Pile Cover—Can It Replace Plastic Tarps?

There is currently great general interest in reducing the use of fossil-based materials. Fossil-based tarps are still widely used as cover for wood chip storage piles, causing additional waste or requiring further waste treatment in the supply chain. This study aimed to investigate the performance of an innovative bio-based wood chip pile cover compared to conventional treatments (plastic-covered and uncovered) in eastern Finnish conditions. The experiment evaluated the drying process during the storage of stemwood chips during 5.9 months of storage. It included the developments of temperature, moisture content, heating value, energy content, basic density, particle size distribution, and the dry matter losses of a total of six piles. As a result, the forest stemwood chips dried by 11%, with dry-matter losses of 4.3%, when covered with the bio-pile cover. Using the plastic covering, the forest stemwood chips dried by 22%, with dry matter losses of 2.9%. At the end of the experiment, the energy content in plastic-covered piles was 6.1% higher than uncovered piles and 3.1% higher than bio-pile-covered piles. While differences in the key drying performance parameters can be observed, the differences between uncovered piles and those covered with plastic tarps, as well as between the bio-based and the uncovered piles, were not statistically significant. We conclude that the bio-based cover, under the studied conditions, do not render better storage conditions than in current practices. However, our study indicates possible fossil-substitutional benefits by using a bio-based cover, which calls for further R&D work in this matter

Estimating the Characteristics of a Marked Stand Using k-Nearest- Neighbour Regression

The purpose of this study was to develop the k-nearest-neighbour method as a wood procurement planning tool. Traditionally, sampling measurement of standing trees has been used to obtain advance information on marked stands. In this study, key figures such as sawtimber/pulpwood ratio in pine and spruce stands, diameter and height distribution in spruce stands, diameter and quality distribution in pine stands, and quality distribution by diameter classes in pine stands were estimated using k-nearest-neighbour regression. The material consisted of 716 stands. Stands were located in the eastern Finland. Information regarding every stand was collected from the information system of one large Finnish timber-procurement organization. The accuracy of the k-nearest-neighbour method was compared with the traditional planning inventory method and stand inventory method. The created model was found to be a useful tool in the planning of wood procurement

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