Browsing by discipline "Skoglig ekologi och resurshushållning"
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(2013)Increasing fossil fuel prices, concerns about domestic energy security and demand for environmentally friendly, low carbon energy sources are renewing interest in using wood for energy. State and federal government have responded to increased interest with legislation that promotes renewable energy. Logging residues important role as an energy feedstock and environmental component has been a central topic of discussion for the growing forest energy sector in the United States. Over the last five years, I have studied forest harvest residues in the southern United States and abroad. My principle research focus has been the rapid inventory of residues, determination of their stocking and the identification of factors influencing that stocking. This composite report provides a detailed account of three studies based on five years of data in North Carolina, Georgia and southern Sweden. Provided in the report is an adapted method to inventory scattered and piled forest harvest residues, the relationship of harvest residues and harvest systems and a wood energy recovery rate for low end biomass within intensively managed loblolly pine forests. The goal of providing these studies is to contribute useful observations to the ongoing discussion about forest harvest residues and to provide a sampling framework others can employ to do similar studies.
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(2017)Primary peat formation, infilling (terrestrialization) and paludification are the three main kinds of peatland formation processes. A peatland can develop over previously drier mineral soil if water table level rises or previously formed mire grows or expands. In Finland, the expansion of mires has been occasionally fast and in major part of ombrotrophic raised bogs it has occured while the mire has been in the minerotrophic fen stage. However, based on previous studies there have been different speculations whether the paludification still continues. Paludification study site at the edge of peatland and forested mineral soil was established in Häädetkeidas Strict Nature Reserve in year 1931. The study site, with a set of 4 transects, was studied in 1931, 1945, 1957 and 1997. Vegetation analysis on these permanent transects was repeated in 2016 as a part of this thesis. The aim of this study was to describe the variation of vegetation at the edge of the mire and forested mineral soil and study how the vegetation and plant species assemblies have changed between the years 1931–2016. A long-term vegetation study can reveal whether the species have changed from forest-dominated species to peatland-dominated species and does the paludification process still continue. The paludification process was studied by estimating the canopy-cover of ground layer and field layer vegetation and litter cover, measuring peat thickness, the thickness of aerated peat layer and anoxic peat layer and forest cover in four transects, consisting of 180 subplots. Non-metric multidimensional scaling (NMDS) was used to describe the data. Ground and field layer vegetation were examined by comparing the species’ average cover and frequencies. Environmental variables were studied by correlation analysis. Differences in peat thickness and in the coverage of Sphagnum-mosses between the examination years were studied with oneway variance analysis and t-test. In all four transects the coverage of Sphagnum-mosses had increased between the years 1931 and 2016. The coverage of forest mosses had decreased in two out of four transects. Succession related changes in species were observed in both vegetation layers. There was variation in the vegetation development between the transects and they seemed to be in different stages of the succession and paludification processes. In 93 percent of the study plots the thickness of peat layer had increased during the last 19 years. The changes in vegetation between the years 1931 and 2016 as well as the growth of the peat layer suggests that the paludification process still continues.
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(2013)Domestic cattle grazing as a disturbance factor to the vegetation structure is investigated. It is concluded that the process of heterospecific attraction plays as important a role as vegetation structure in predicting waterfowl assemblage patterns. The study site, an estuarine wetland in an urban zone in Helsinki, is studied during one staging period. Two sets of shorelines are focused on, grazed and ungrazed. Avian assemblages are compared in both types of shorelines based on variables of community structure and habitat resource use. The two most influential variables are aquatic invertebrate biomass index as food supply, and bare shoreline proportion as habitat structure indicator. The process of competition as regulating factor in forming avian aggregations is ruled out by confirming that sufficient amounts of habitat resources, food and space are available. The co-occurrence patterns of foraging guilds are analyzed. Heterogeneous vegetation structure, combined with social attraction, influences avian distribution patterns. Niche partitioning is absent across the whole landscape as invertebrate food resource is not a limiting factor. Microhabitat use within plots is evenly distributed. The constantly popular microhabitats are sections of the grazed shorelines where resource partitioning is absent. Avian habitat preferences are shaped by extent of available bare shoreline and the presence of other waterfowl. The latter effect is confirmed both as conspecific and heterospecific attraction. It is the first time this wetland, which is also a designated Natura 2000 and Ramsar site, is being investigated for wildlife community dynamics. The site does not suffer from major environmental threats and has potential for more waterfowl consumers. In view of its international significance, this and similar research can aid urban planners in Reserve management to enhance avian diversity towards attracting species of more conservation concern.
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(2010)Tässä työssä tarkastellaan hakkuu-uramenetelmän kilpailukykyä ajouramenetelmään verrattuna erityisesti turvemaiden puunkorjuussa. Menetelmien välisistä edullisuussuhteista eri oloissa on hyvin vähän aikaisempaa tutkimustietoa. Hakkuu-uramenetelmä on harvennushakkuisiin soveltuva työmenetelmä, joka perustuu ajourien väliin tehtäviin hakkuu-uriin, joita käyttää vain hakkuukone. Hakkuu-urien avulla ajouraväliä voidaan säätää välillä 20 - 40 metriä. Hakkuu-urasta käytetään myös nimitystä ”haamu-ura”, sillä se on normaalia ajouraa kapeampi ja varsin huomaamaton maastossa. Vertailumenetelmänä on perinteinen ajouramenetelmä, jossa hakkuukone ja metsätraktori käyttävät samoja uria ja ajouraväli on noin 20 metriä. Tutkimusongelmaa lähestyttiin tarkastelemalla miten työmenetelmien välinen kilpailukyky muuttuu siirryttäessä kangasmaan ensiharvennuksesta turvemaan ensiharvennukseen. Kilpailukyvyn näkökulmia olivat hakkuun ja metsäkuljetuksen tuottavuus, korjuukustannus ja korjuujälki. Tutkimus rajattiin kesäaikana tapahtuvaan puunkorjuuseen. Työn tuottavuutta tutkittiin aikatutkimuksella kangas- ja turvemaan olosuhteissa molemmilla työmenetelmillä. Aikatutkimusaineiston perusteella laadittiin hakkuun tuottavuutta kuvaavat lineaariset regressiomallit. Työn tuottavuuden lisäksi kenttäkokeessa tutkittiin korjuun kustannuksia ja korjuujälkeä. Kenttäkokeen tutkimustulosten tueksi haastateltiin lisäksi hakkuu-uramenetelmää käyttäviä urakoitsijoita ja heidän urakanantajiaan. Haastattelun avulla pyrittiin selvittämään parhaat käytännöt hakkuu-uramenetelmän käytöstä erilaisissa leimikoissa ja olosuhteissa. Hakkuu-uramenetelmän kilpailukyky hakkuun tuottavuuden ja kustannusten osalta on parhaimmillaan tiheissä puustoissa. Turvemaille tyypilliset olosuhteet, kuten harva puusto ja alhainen hakkuukertymä heikentävät hakkuu-uramenetelmän kilpailukykyä. Hakkuu-uramenetelmän käyttö tuottaa ajouramenetelmää suuremman puutavaran tienvarsitiheyden, jonka vaikutus metsäkuljetuksen tuottavuuteen ja kustannuksiin on edullinen. Ajouravälin kasvattaminen 40 metriin turvemaalla ei kuitenkaan ollut mahdollista, joten hakkuu-uramenetelmän tienvarsitiheys jäi lähes samalle tasolle ajouramenetelmän kanssa. Ongelmana hakkuu-uramenetelmällä oli myös ajouramenetelmää pienemmät kourakasat. Kasakoko on kuitenkin paljon kiinni hakkuukoneen kuljettajan työskentelytottumuksista. Korjuujälki oli molemmilla menetelmillä varsin hyvä, mutta hakkuu-uramenetelmän kilpailukyky parani kuitenkin suhteessa ajouramenetelmään turvemaalle siirryttäessä.
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(2017)Pro Gradu -tutkielman tavoitteena oli tutkia High Capacity Transport-yhdistelmien polttoaineen kulutusta ja päästöjä. Tutkimus on osa Metsäteho Oy:n HCT-tutkimushankkeita. Tutkimus toteutettiin Metsätehon yhteistyöyritysten avulla ja tuella. Tutkimuksessa tarkastelin kolmea 84-104 tonnin painoista HCT-yhdistelmää ja niiden verrokkiajoneuvoja. Verrokkien kokonaispaino oli 76 tonnia. Pro Gradu -työssä käydään lävitse yhdistelmien rakenne ja tiedonkeruussa käytetyt järjestelmät. Tiedonkeruujärjestelminä on käytetty Scanian Fleet Managementia, Volvon Dynafleetia ja Paetronicsin valmistama Econenia. Tulosten mukaan HCT-yhdistelmät voivat merkittävästi parantaa puutavaran hankinnan polttoainetehokkuutta. Tämä helpottaisi Suomen pääsyä kansallisiin ja EU:n asettamiin päästötavoitteisiin.
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(2014)The Finnish Forest Center produces forest resource data for the use of land owners and the actors in the forestry sector. The data is produced mainly by means of airborne laser scanning (ALS), and it is managed in a nationwide Aarni- forest resource information system. The produced data also includes stand-specific proposals for harvesting and silvicultural treatment. These are usually generated by a simulation, which also provides suggestion for a year of the action. The collection of forest resource data is based on the Area-based approach (ABA). In the method, the forest charac-ters, such as tree attributes measured on field sample plots, are predicted to the whole invention area by the corre-sponding laser- and aerial photo features. Forest characters are predicted to the grid cells 16 x 16 meters in size. In Aarni, the treatment simulation is based on the averages of the tree attributes generalized from the grid cells to the stand. The method does not regard a possible within-stand variation in tree density, which may cause, for ex-ample, delayed thinning proposals especially for the stands with grouped trees. The main aims of this study were: 1. To create a new method in which, in addition to the tree attributes, the subsequent treatment and its timing were simulated to grid cells. After that, special decision rules were created to derive the treatment from the grid cells to the stand. 2. To compare the treatments derived with the decision rules with the normal Aarni simulation of 291 field-surveyed stands to determine which method is better. A related action was also taken: A relationship between within-stand variation and a timing of the simulated treat-ments was also surveyed. This was accomplished by comparing the deviation of tree attributes of the grid cells (e.g. basal-area) with the corresponding attributes of the stand. Presumption was that, particularly in the stands with grouped trees, the problem of delayed thinning could be reduced by using decision rules. The results suggest that the decision rule method gives slightly better results than Aarni simulation in the case of the timing of treatments. The method gave the best results in the young stands where the field treatment proposal was first thinning. The deviation of the basal area of trees in the grid cells appeared to be slightly larger than aver-age in the stands with a large variation in tree density. In these particular stands, the decision rules mostly derived better timing for thinning than normal Aarni simulation.
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(2017)Hirvenmetsästys on Suomessa suurelle osalle metsästäjistä tärkeä harrastus, ja yhteiskunnallisestikin sillä on suurta merkitystä. Se on metsästyspäivissä ja lihan arvossa mitattuna Suomen merkittävin metsästysmuoto. Hirvenmetsästys tapahtuu usein seuruemetsästyksenä. Seuruemetsästys tapahtuu suurella joukolla laajoilla alueilla, jolloin syntyy päällekkäisyyttä ja mahdollisia ristiriitoja muun virkistyskäytön kanssa. Mikäli samalla metsästysalueella on useita hirviseurueita (esim. useita Metsähallituksen aluelupaa hakeneita seurueita metsästää samalla alueella), saattaa niiden välille syntyä kitkaa. Tällaisten seikkojen vuoksi harrastuksen sosiaalinen kestävyys saattaa kärsiä. Miten sosiaalista kestävyyttä voitaisiin parantaa? Mitä paremmin metsästysjärjestelyistä vastaavat viranomaiset tuntevat alueellaan metsästävät hirviseurueet, sitä paremmin ristiriitoihin ajautumista kyetään ennaltaehkäisemään. Yksi keino tutustua hirviseurueisiin on niiden profilointi. Profiloinnilla tarkoitetaan tässä työssä homogeenisten osajoukkojen tunnistamista heterogeenisesta vastaajajoukosta. Työssä tarkastellaan Pohjois-Suomessa metsästäviä hirviseurueita heidän taustojensa, toimintansa ja häiriöitä koskevien näkemystensä suhteen. Vastaajajoukko koostuu metsästyslain 8§ tarkoittaman vapaan metsästysoikeuden alueella metsästävistä hirviseurueista. Näistä seurueista Metsähallitus on kerännyt aineiston vuonna 2013. Alueella metsästää noin 1 400–1 600 hirviseuruetta, joista kysely lähetettiin kaikille, joiden yhteystiedot olivat saatavilla (n = 1 388). Näistä vastasi 825 (59,44 %). Vastauksia kertyi koko tutkimusalueelta melko tasaisesti, muutamaa poikkeusta lukuun ottamatta. Profiloinnissa käytettiin nominaaliasteikollisten muuttujien LCA:ta (Latent Class Analysis). Aineiston herkkyyttä menetelmävalinnalle tarkasteltiin järjestysasteikollisten muuttujien faktorianalyysillä ja korrelaatioanalyysillä. Jaoin seurueet LCA:lla 2–6 profiiliin. Eri profiilimääriin jaotteluja arvioin informaatiokriteereillä ja pyrin löytämään tulkinnallisesti mielekkään, aineistoon sopivan jaottelun profiileihin. Tällainen oli etenkin neljän profiilin ratkaisu. Nimesin eri profiilien seurueet ja analysoin eri profiilien esiintymisen riippuvuutta suhteessa seurueiden sijoittumiseen tutkimusalueella etelä–pohjois-suunnassa. Tämän tarkastelun mukaan ns. vapaan metsästysoikeuden alueella on 1) yksilömetsästystä suosivia pienseurueita (Ylä-Lappi), 2) monimuotoisia suurseurueita (Keski-Lappi), 3) seisontahaukkua suosivia seurueita (Etelä-Lappi), sekä 4) seisovaa ja siirtyvää haukkua suosivia seurueita (tutkimusalueen eteläosa). Tarkastelin myös tunnistamieni profiilien yhteyttä siihen, millaisia häiriöitä tai ristiriitoja niissä oli koettu. Häiriönä erityisesti nousi esille suden merkitys hirven metsästystä haittaavana tekijänä profiilissa 4). Kun tarkastelin pelkästään muiden seurueiden kanssa ristiriitoja kokeneita seurueita (40 % kaikista seurueista) tunnistin yhden profiilin, jossa oli ongelmia koettu muita enemmän. Tämä profiili muodostui seurueista, jotka olivat osallistujamäärältään suurimmat ja käyttivät myös paljon koiria, samoin he kuuluivat aluelupapäätökseen monen muun seurueen kanssa. Näihin seikkoihin vaikuttamalla ja niistä tiedottamalla, voisi olla mahdollista parantaa alueen hirvenmetsästyksen sosiaalista kestävyyttä.
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(2013)The largest wetland drainage project in Michigan was initiated in 1912 near the town of Seney in the eastern Upper Peninsula. This project included the construction of a series of drainage ditches intended to prepare the land for agricultural use. The largest of these ditches was the 35 km-long Walsh Ditch. Much of the drained wetland affected by the Walsh Ditch is now managed by the U.S. Fish and Wildlife Service as part of Seney National Wildlife Refuge (Seney NWR). Starting in 2002, a series of earthen ditch plugs were installed along the length of the ditch found within Seney NWR (and adjacent to the Seney Wilderness Area) in an attempt to restore the hydrology and ecological integrity to the affected wetlands and streams. The plugs North of C-3 Pool were completed in 2002. The ditch plugs South of C-3 Pool were completed in 2005. This study explores the effect of the ditch plugs on the hydrology and vegetation structure in the adjacent landscape north of C-3 Pool at multiple scales. Plot level measurements of hydrology and vegetation, combined with an analysis of landcover change over the entire study area, indicate that some areas are converting from artificial upland communities created by wetland drainage to more natural wetland community types. Mortality of upland tree species and colonization by typical wetland species are good indications that these sites will continue to develop into wetland ecosystems over time. However, some areas have shown no response to the hydrologic restoration. This is expected, as areas of the landscape were upland (referred to as “pine islands” in the literature) before Walsh Ditch and should remain so as natural hydrology is restored to the area. Landcover change analysis showed a decrease in open water of 90.82 ha, a decrease of upland area of 67.88 ha and an increase in wetland area of 151.88 ha. The areas of change were concentrated around stream channels and in the area just east of Walsh Ditch. With time, it is possible that areas further removed from the ditch will show a shift towards more natural hydrology and vegetation composition, but for the areas furthest removed from the ditch this may require active management.
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(2017)Among small and medium size companies in developing countries, innovations are needed to improve profitability of the business and to survive in global competition. Not only the globalization and competition are the challenges, but also new legality proof requirements set by EU and governments places companies in a new situation. This paper examines the value chain of small scale producer´s wooden furniture, from Jepara, Indonesia to the EU market. The value chain from a forest to ready furniture is analyzed through deep interviews of key informants. Also the policies which have influence on the value chain, such as the EU timber regulation (EUTR) and Indonesian national timber legality assurance system (SVLK) are taken into account. The aim of the study is to localize the strengths and the weaknesses of the value chain and to find solutions either to integrate or to improve the competitiveness. The study led to new recommendations for furniture businesses in Jepara and found out that forest related policies are impacting on the value chain in several ways.
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(2016)Smallholder tree plantations possess a substantial capacity to produce sustainable timber material, while providing additional income to farmers. This thesis studies the effects of forest management practices to tree growth and tree quality in smallholder pine woodlots in Tanzania. The analysed data consists of woodlot inventory measurements and farmer interviews from four villages in Njombe region. Additionally, key-informant interviews were conducted with relevant stakeholders to briefly explore the timber value-chain of the region. The results indicated that variety of factors affect to the conditions of the smallholder woodlots in the case study area. The main finding was that implemented forest management practices had varying and complex effect on both, tree growth and quality. While some of the practices were observed to be associated with better growth performance, some were also observed to have a negative effect on growth. However, large variety persisted between these effects. This indicates that it is of high importance how practices are done, rather than what sort of individual practices are implemented. Similar observations were made regarding the connection between tree quality, which was assessed by rate of various defects in trees. Alarmingly, the amount of implemented practices was observed to generally increase the share of trees with severe defects. This further highlights the importance of the quality of forest management. Furthermore, the effect of seed and seedling origin to tree growth and quality was analyzed. There was clear improvement in growth with stand established from seedling acquired from private or governmental nurseries, compared to seedlings grown by farmers themselves. This relates to seed origin, as in nurseries the seedlings are generally grown from seeds of controlled breeding programmes, whereas the farmers normally collect the seeds where they can find them. However, seed or seedling origin did not have any major effect on the rate of observed defects, indicating that the forest management practices together with unmeasured site characteristics play a dominant role here. The key findings of this thesis highlight the importance of market demand for timber, as in long-term, the tree plantations are only managed productively when there are markets where the timber can be sold. In the case study area, the market demand was high, and in some ways, even too high, as even poor quality trees were generally sold easily, though at reduced price. This is a result of limited governmental forest plantation resources failing to meet the growing domestic demand for sawn timber. Too high demand may cause an incentive not to invest in improvement of plantation performance, and therefore prevent development of the whole processing-chain. One solution to this would be introducing adequate quality-based timber pricing system. If correctly done, this would create appropriate incentive for smallholders to invest in their tree plantation management to be able to receive price premiums for good quality trees. However, many obstacles remain. For example, bad accessibility to smallholder woodlots is preventing cost-effective transportation of roundwood to be processed in stationary sawmills with improved sawing machinery. As a general conclusion, there is substantial potential in smallholder tree plantations to provide timber to growing global demand. However, in large parts, this potential is still un-tapped, and significant support efforts are needed to be able to provide good quality material and to access production of value-added products for domestic and export markets. Nevertheless, in Tanzania smallholder tree plantations are already providing timber to domestic markets, and the importance is only increasing as other sources fail to meet to the ever-growing demand. If adequate amount of land is available, and farmers have equal possibilities to participate, smallholder tree growing can provide sustainable source of timber, while also contributing to the improvement of rural livelihoods.
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(2015)Spruce stumps have been harvested in large scale for combustion in heat and power plants since the beginning of the 21th century. Normally the stump harvesting operations are done by excavators. On stump harvesting areas the risk to serious soil damage is greater because there are more driving tracks on the ground than in original logging operations. In stump harvesting areas machines cannot get benefit from frozen soil or coarse roots to increase bearing capacity. Compacted soil can reduce tree root penetration, increase nutrient leaching and affect soil water properties. The aim of this study was to clarify if the stump harvesting compacts the forest soil and if it possibly recovers in the long run. I also studied how much the soil surface will be disturbed after stump harvesting operations. In this study there were three stump harvesting sites which varied in the time passed since harvesting. Comparable reference sites were chosen from nearby areas where the stumps were not harvested. All sites were located in Southern and Central Finland. Every site had three 5 x 5 meter study plots in which soil strength was measured by a cone penetrometer. Soil core samples were also taken from every study plot. The soil surface disturbance proportions were estimated visually and using a soil sampling probe. Measurements were carried out under summer of 2014. The results indicate that the soil has been compacted by stump harvesting in the 4-year-old site but differences were statistically significant (p<0.05) only in 2 of 6 depth classes. In the middle aged (7 years) site the impacts were the opposite. In the oldest (13 years) site there were no differences between the treatments. The soil surface in stump harvesting sites has been disturbed most in the youngest site (50 %), and at the other sites the disturbed soil surface proportion was about 40 %. About 25 % of soil surface was disturbed in all reference sites. The soil disturbance results in this study were minor compared to other studies in the literature. In the upper depth classes soils were not too compacted for tree growth, root penetration and nutrient uptake. This indicates that the changes in soil structural properties caused by stump harvesting are not harmful for forest growth but more long-term studies are needed.
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(2015)The purpose of this Master’s thesis is to find out what kind of views Finnish forest professionals have concerning forest data that’s based on laser scanning. Lately there have been a lot of changes in forest organizations and in the forest professional’s work environment. One of these big changes is that forest data based on laser scanning is becoming a part of operative forest planning. Extensive mapping of forest areas is more often done with airplane or satellite remote sensing. This way it is possible to cut down costs and make mapping more efficient by reducing sample plots and using more remote sensing data. This study focuses on this change from the perspective of an employee of a forest planning or advisory organization. The theoretical frame is action theory. The aim is to find out how this new forest data suits forest planning and is the quality of the data good enough to make forest plans. This research is a very topical subject because forest data that is based on laser scanning is going to bring significant changes to the forest planning field practices. The strengths of laser scanning are that it is objective and it gives at least as accurate tree data measures as other methods. Forest data based on laser scanning is also quite inexpensive, it can be acquired very quickly and it is easy to update. There is very little previous research about this subject. It is likely that new researched information is going to improve the usability of forest data that is based on laser scanning at forest planners’ everyday work. This research was implemented with web-based questionnaire and both quantitative and qualitative methods where used. The sample was taken from three forest organizations (The Finnish Forest Centre, OTSO Forest Services and The Forest Management Associations). The aim was to select forest professionals that use laser scanning based forest information at their work. The whole sample size was 929 respondents and the response rate was 37 percent. The research methods used were statistical description, cross tables and qualitative thematic analysis. When we look at the results it is clear that there are differences on how regularly forest data based on laser scanning is used in these three organizations. The Finnish Forest Centre and OTSO Forest services are using forest data based on laser scanning more often than The Forest Management Associations, but in all of these organizations there was a desire to use it more. The results of this study clearly show that a main part of forest professionals think that this new method is suitable for forest planning at least as an aid to making forest plans. The forest professionals also thought that there is still room for improvement in this new forest data collection method. There are too many errors at reliability especially in young and untreated forest. There is also a difficulty to determine the ratio of tree species. Generally it can be said that forest data based on laser scanning is liked among the forest professionals and they would like to use it more in the future.
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(2014)Use of wood as energy source has increased considerably partly due to financial investments made by finnish forestry companies and partly because of political guidance. Especially the use of wood chips made from logging residues and wood trunks increased. With current methods, the harvesting of wood trunks for energy use is problematic due to low productivity and high costs. In this research the light pruning of energy wood trunks was studied and compared with full pruning and whole tree harvesting of energy wood trunks through the whole procurement chain. The research was divided into four phases. In the harvesting phase the productivity of three different ways to prune energy wood trunks was studied. In the forest transportation phase payloads between different pruning ways were studied as well as cargos loading and unloading times. In long distance transportation phase differences between payloads were studied. In the final product phase moisture percentages of wood chips between pruning ways were measured. In the harvesting phase the highest productivity was achieved with whole tree harvesting. When using full pruning the productivity was lowest. The productivity of light pruning took a stand between these two. Highest payload was achieved with light pruned trunks in the forest transportation phase. Second highest payload was measured with full pruned trunks. The payload of whole trees was smallest. On the other hand, whole tree trunks were fastest to load followed by light pruned and full pruned trunks. When unloading, the results were completely opposite. In the long distance transportation the biggest payload was measured with fully pruned trunks. The payload was second biggest with light pruned trunks. Payload of whole trees was measured as smallest. The wood chips made from fully pruned trunks were driest when the moisture percentages of wood chips made from differently pruned trunks were compared. Chips made from light pruned trunks were second driest. The biggest moisture percentage was with chips made from full trees. The whole procurement chain of full trees was the most efficient in terms of economy. On the other hand, the unit costs of light pruned trunks and full pruned trunks were clearly lower than the unit costs of full trees. Based on result of this study it can be said that light pruning is economically and in terms of productivity compet-itive method to prune trees when compared to other methods.
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(2014)Urban forests of Helsinki city are managed in multiple ways and several forest values are taken into account in forest management. Strong forest management actions that change the forest landscape radically have been done quite seldom, which has increased the proportion of old forests. The risk of spruce bark beetle (Ips typographus) outbreaks is often evident especially in older Norway spruce (Picea abies) forests of low vitality. In the winter of 2011 to 2012 storms caused windfalls in some areas of the urban forests in Helsinki city, which increased the risk of spruce bark beetle outbreaks even more. The objective of this study was to assessment the risk of spruce bark beetle outbreaks in the urban forest of Helsinki city and present future forest management recommendations to control the spruce bark beetle damage. Monitoring with pheromone baited traps was used as the main investigation method. Results were compared with spruce bark beetle risk estimates found in literature. Other factors affecting the risk of spruce bark beetle, for example the amount of living Norway spruces infested with the spruce bark beetle, were observed as well. Monitoring with pheromone traps was carried out with 36 traps in three regions in Helsinki Central Park and in one region in Herttoniemi between 6th of May and 4th of July in 2013. Pheromone trap model, WitaTrap Multi Funnel, and pheromone bait Ipsowit® Standard were manufactured by Witasek company. Altogether 79 210 spruce bark beetles were trapped. According to the monitoring results the risk of spruce bark beetle can be high in one region in Central Park area. Living Norway spruces infested by the spruce bark beetle were found in two regions and also in one area outside the investigation area. Based on the results the areas with greatest risk to spruce bark beetle damage were the neighboring areas of previous damage as well as forests with suitable breeding material for the spruce bark beetle. The risk can also be high in Norway spruce forests of low vitality and in recently formed, sun-exposed forest edges dominated by Norway spruce. Forest management recommendations in short time interval to control the spruce bark beetle risk are as follows 1) forest monitoring and removal of spruce bark beetle infested live Norway spruces before Midsummer, 2) observation of storm damage and removal of large diameter Norway spruce windfalls as a rule, 3) monitoring the weather conditions and 4) following national announcements related to the spruce bark beetle risk status. Forest management recommendations for longer time interval are phased regeneration fellings of risk prone Norway spruce forests and changing the forest structures more resistant to spruce bark beetle damage in the future.
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(2014)To achieve the appointed goals set in the national climate and energy strategy it is important to launch biomass into markets more effectively. In addition to biomass from clearing sites energy wood needs to be procured from young stands. First thinnings have been neglected to great extent in Finland mainly because of low profitability. The targets have been achieved only once during last decade. Expanding energy wood procurement to young stands increases the need for resources. Therefore more effective operating machines should be developed. The challenge is in launching these prototypes into testing and commercial markets. Fixteri Ltd. has developed a whole-tree bundler in order to enhance harvesting of small-diameter energy wood from young stands. This method is meant to reduce transportation costs through load compaction. The aim of this research was to study the productivity of cutting and bundling of whole-trees using Fixteri FX15a bundling unit and to clarify the competitiveness of the whole production chain compared to rival methods. The harvesting was studied trough video analyze in order to detect factors limiting the productivity. 35 whole-tree bundles were produced in young Scots pine stand. An average weight and volume of the bundle were 502.5 kg and 463 dm³. It took 3.38 min to produce one bundle. FX15a bundling unit was fitted to Logman 811FC base machine. Accumulating Nisula 280E+ felling head was used. An average performance per effective working hour of 9.74 m3 was recorded when average volume of removal was 37.3 dm3. The operator used multi-tree cutting effectively in average 3.1 whole-trees per work load. The share of multi-tree cutting was 96 percent. The performance of prototype FX15 was significantly lower than the performance of FX15a. The performance of 5.07 and 5.86 m³/h0 were recorded when average volumes of removed trees were 28.4 and 41.1 dm³. It was observed that the productivity of FX15a was higher compared to the harvesting of undelimbed trees when average volume of removed trees was less than 70 dm3. Harvesting and off-road transportation of whole tree bundles was more profitable when average volume of removal was under 95 dm3. Total costs of wood chip supply chain were lower compared to harvesting of undelimbed trees when average volume of removal was less than 85 dm3. Total costs of wood chip supply chain were higher compared to harvesting of undelimbed trees regardless of average volume of removed trees when FX15 bundling unit was used. When includung the possible energy subsidies (max 30 %) for whole-tree bundling and pre-clearance-related additional costs for harvesting of undelimbed trees into account the potential number of harvesting sites increases significantly. Drying the bundles plays an important role since high moisture content in the bundles after road side storing may endanger the competitiveness of the whole supply chain when bundles are burned to produce energy. Although bundling whole-trees seems to be a competitive alternative in harvesting small-diameter energy wood there are still several questions unanswered. The method should be studied in greater depth by varying harvesting conditions and machine operators. Also the potential of on-road transport and bundle features needs further study.
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(2017)Biological sprout control with Chondrostereum purpureum (Pers. ex Fr.) Pouzar was integrated to mechanized early cleaning. In this method, liquid with hyphae of C. purpureum was sprayed on the freshly cut stumps. C. Purpureum has been studied for biological sprout controlling since 1980’s. This species is a common basidiomycete saprophytic fungus found in Finland, and thus does not cause a biological risk. Early cleaning and pre-commercial cleaning of young forests have not experienced major innovations since the brush saw. Mechanizing of work has been thought to be a solution for increasing working costs. Chemical sprout control has been restricted to special targets, which addresses more interest on alternative biological methods. In this research, effectivity of biological stump treatment and factors affecting the results were investigated. Early cleaning was done in eight study sites during June–September 2014. Inside the sites, area was partly treated with mechanical cutting and by applying C. purpureum stump on freshly cut stumps, and partly with mechanical cutting only (a control treatment). 15 circular sample plots with a radius of one meter per treatment were founded in studied young forest stands (altogether 480). All stumps and saplings with a diameter over 5 mm were studied in 9-10/2015. The data includes altogether 2030 hardwood stumps. Stump mortality, number of living sprouts and the height of the sprouts were modelled for birch, rowan, aspen and willow. Results revealed that sprout control with C. Purpureum affected mortality, sprout number and height of birch sprouts. Mortality increased with time lag after treatment and with increasing stump diameter. The results showed that mortality level of 50 % was reached after two growing seasons. Sprout number increased with increasing stump basal area and decreased with time lag after treatment. Number of other saplings on the plot and soil moisture effected negatively on sprout number. Sprout height increased with increasing stump basal area and stump height. Number of other saplings and stumps on the plot affected birch sprout height negatively. Results of C. Purpureum stump treatment were weaker for other studied hardwood species (rowan, aspen, willow) and other factors affected more than biological sprout control. Effectiveness of sprout control in this study was weaker than in other studies presented recently. Time span of this study was considerably short and final results are seen some years after stump treatment. Another factor to consider is the spreading method used in this study. Stump treatment integrated to mechanized early cleaning of young conifer plantations need to be developed further so that this method would be profitable in practical silviculture.
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(2015)Puun käyttö lisääntyy lähivuosina metsäteollisuuden isojen investointien ja uusiutuvan energian tavoitteiden seurauksena merkittävästi. Suurin osa lisääntyvästä puun käytöstä tulee kasvatushakkuilta, mistä suuri osa on nuorten metsien hakkuita eli ensiharvennuksia. Energiapuun ja kuitupuun käytön kasvun myötä metsänomis-tajan on tärkeä tietää millaisesta metsästä mitäkin puutavaralajia olisi järkevintä korjata. Tämän tutkimuksen tarkoituksena oli selvittää, mikä korjuumenetelmä tuottaa parhaan nettotuloksen harven-nushakkuusta metsänomistajalle leimikkosuunnitelman ennakkotietojen perusteella sen hetkisellä puutavara-lajien hinta-asetelmalla. Tutkimuksessa tarkasteltiin kolmea korjuumenetelmää: normaali ainespuun korjuu tavaralajimenetelmällä, energiapuun korjuu rankamenetelmällä ja aines- ja energiapuun yhdistetty korjuu eli niin kutsuttu integroitu korjuu, jossa puutavaralajit olivat tukki, pikkutukki ja energiaranka. Tutkimusta varten kerättiin hakkuun vertailuaineisto Varsinais-Suomesta, mikä sisälsi 8 leimikkoa, 22 koealaa, 2135 runkoa. Koealoilta mitattiin metsässä pinta-ala, ajouran pituus ja tehoajanmenekki. Puutavaralajikohtaiset kertymät mitattiin hakkuukoneella. Hakkuussa käytettiin yksinpuinmenetelmää. Metsäkuljetuksen tuottavuus ja kustan-nukset määritettiin laskennallisesti. Tutkimuksessa käytettiin lisäksi Metsäntutkimuslaitoksen ensiharvennus-ten korjuuoloja selittävää aineistoa, joka sisälsi 25 mitattua ensiharvennusleimikkoa. Hakkuun tehotuntituottavuus E0 oli ainespuun hakkuussa 9,9 m³/h, integroidussa hakkuussa 10,4 m³/h ja energiapuun hakkuussa 10,7 m³/h, kun poistuman käyttöosan keskitilavuus oli 80 dm³. Energiapuun hakkuu oli keskimäärin 8,5 % tehokkaampaa kuin ainespuun hakkuu, kun poistuman keskitilavuus oli 50‒100 dm³. Energiapuun hakkuu oli tehokkainta rungon koosta riippumatta ja ainespuun hakkuu kalleinta 135 dm³ asti, jolloin integroidun hakkuun tuottavuushyötyä ei enää ollut. Metsäkuljetuksen laskennallinen tuottavuus kes-kimääräisellä ensiharvennuksella, jossa kertymä oli 50 m³/ha, oli ainespuulla 6,1 m³/h, integroidulla 7,8 m³/h ja energiapuulla 9,3 m³/h. Kahden puutavaralajin lisäys energiapuun korjuusta integroituun korjuuseen nosti metsäkuljetuksen keskihintaa 15 % eli noin 7,5 % puutavaralajia kohti. Metsäntutkimuslaitoksen aineiston perusteella energiarankaa kertyy energiapuun korjuussa keskimäärin 4,2 % enemmän kuin ainespuuta ainespuun korjuussa. Integroidussa korjuussa energiarankaa kertyy 10,2 % enemmän kuin kuitupuuta ainespuun korjuussa. Teoreettisesta tukkikertymästä hyödynnettiin hakkuun vertai-luaineistossa keskimäärin 64 %. Tutkimuksen tulokset osoittavat, että energiarangan hakkuu yksinpuinmenetelmällä ei ole kannattavaa. Tutki-muksen perusteella harvennushakkuilta kannattaa aina erotella tukkipuu, mikäli puumarkkinatilanne ja kauko-kuljetuslogistiikka sen sallivat. Analyysin mukaan ainespuun korjuu on lähes poikkeuksetta kannattavin me-netelmä, kun energiarangan ja kuitupuun hankintahinnan ero on nykyisellään noin viidessä eurossa. Puun hintojen herkkyysanalyysin perusteella integroitu korjuu on kannattavinta metsänomistajalle, kun energia-rangan ja kuitupuun hintaero laskee alle 3,5 euron. Energiarangan korjuuta tulee tehostaa esimerkiksi joukko-käsittelyllä, jotta sen korjuu olisi kannattavampaa kuin integroitu korjuu ja ainespuun korjuu.
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(2015)Kosteikon perustaminen tai kunnostaminen on ympäristöä muuttava hanke, jolla liki aina on sosiaalisia vaikutuksia alueelle. Muutokset ihmisten lähiympäristössä heijastuvat heidän elinoloihinsa, hyvinvointiin sekä viihtyvyyteen. Ympäristöä muuttavien hankkeiden suunnittelijoiden, toteuttajien ja esimerkiksi lähiympäristön asukkaiden näkemykset hankkeen hyödyistä ja haitoista voivat olla moni-naiset ja osin jopa hyvin erilaiset. Sosiaalisten vaikutusten arviointi on menetelmä tai toimintastrategia, jolla hankkeen vaikutuksia ihmisten elinoloihin, hyvinvointiin sekä viihtyvyyteen voidaan arvioida. Tämän tutkimuksen tavoitteena oli pyrkiä tunnistamaan kosteikon perustamisen vaikutuksia toteuttajiin ja lähiympäristöön sekä lähiympäristön asukkaisiin. Tarkastelun kohteina ovat: 1) toteuttajien sekä lähialueen asukkaiden väliset suhteet, 2) intressit kosteikon rakentamiseen, 3) kosteikkojen perustamisen haasteet, 4) toteuttajien kokemukset ja odotukset kosteikon odotetuista ja havaituista vaikutuksista sekä 5) halukkuus perustaa kosteikoita ilman ulkopuolista rahoitusta. Tutkimusaineiston muodostivat kaksi Kotiseutu-kosteikko Life+ -hankkeen mallikohteiden toteuttajille suunnattua lomakekyselyä. Ensimmäinen kysely suoritettiin ennen kosteikkojen toteuttamista ja toinen toteuttamisen jälkeen. Tulkintaa tukemaan suoritettiin kosteikoilla kaivutöiden yhteydessä toteuttajien ja lähialueen ihmisten teemahaastatteluja ja lisäksi puhelinhaastatteluja. Idea kosteikon rakentamiseen kykeni lähtemään monesta erilaisesta suunnasta. Ratkaisevan aloitteen idean muodostumisesta itse toteuttamisen konkreettiseen valmisteluun olivat Life+ -kosteikkojen kohdalla ottaneet liki puolessa tapauksista maanomistajat. Heidän rinnallaan aktiivisina aloitteentekijöinä olivat metsästysseura tai -seurue, mutta yksittäisissä tapauksissa myös moni muu taho. Yleisimmin yhteistyöhön päätyivät aktiiviset metsästävät, kalastavat ja koiraharrastuksissa mukana olevat henkilöt, jotka jakoivat kiinnostuksen luonnon tarkkailuun ja hoitoon. Toteuttajat näkivät kosteikon vaikutukset lähiympäristöön ja sen ihmisiin positiivisina eikä negatiivisia arvioita ilmennyt. Heidän odotuksensa vaikutuksista olivat korkealla ja ne myös toteutuivat. Toteuttajat pitivät keskinäisiä suhteitansa kautta linjan hyvinä tai erittäin hyvinä. Yksimielisimmin toteuttajat näkivät kosteikon arvon luonnonhavainnoinnin mahdollistajana ja sekä vesilintujen määrän lisääjänä. He myös arvioivat, ettei kosteikon toteuttaminen synnyttänyt kateutta muissa alueen ihmisissä. Odottamattomia haasteita toteuttamisen aikana aiheuttivat useimmiten luonnonolosuhteet, ja selviytymisessä auttoi usein osaava kaivinkonekuski. Haasteina koettiin myös lupaviranomaisten hidas toiminta ja Life+ -hankkeen resurssien puute ja kosteikkosuunnittelijoiden lomat. Näistä selvittiin monissa tapauksissa odottamalla vain kärsivällisesti. Kynnyskysymyksenä kosteikkojen rakentamiselle pidettiin ulkoista rahoitusta. Toteuttajat pitivät Life+ -rahoitusta hyvin merkityksellisenä toteuttamiselle. Vaihtoehtona tälle he pitivät lähinnä maatalouden ei-tuotannollista tukea tai Leader-rahoitusta. Muita rahoituslähteitä ei joko oikein edes tunnettu tai nähty merkittävänä. Toteuttamista eteenpäin vieväksi ja toteuttamisen kannalta tärkeäksi vastaajat kuitenkin kokivat Life+ -hankkeen rahoituksen rinnalla sen tarjoaman suunnittelu- ja toteutusavun. Tulosten mukaan kosteikkojen rakentamiselle ei voida määritellä lähtökohtien ja toteuttajatahojen osalta yhtenäistä samaa muottia, jonka mukaan kaikki hankkeet etenisivät. Toteuttajien kokemukset ja odotukset kosteikkohankkeen eri vaiheissa olivat kautta linjan positiivisia ja nämä odotukset voidaan katsoa kytkeytyvän osittain motiiveiksi kosteikkojen perustamisen taustalle. Tulosten perusteella ei näytä olevan esteitä, miksi kosteikkojen rakentaminen ei jatkuisi tulevaisuudessakin. Hyvien tulosten taustalla täytyy muistaa kuitenkin Kotiseutukosteikko Life+ -hankkeen toimiva konsepti, joka mahdollisti sujuvan kosteikkojen toteuttamisen. Lisäksi mallikohteiksi oli valittu sellaisia kohteita, joiden lähtökohdat olivat hyvät. Toteuttajatahojen väliset suhteet sekä maastolliset piirteet olivat myös kunnossa.
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(2012)Forest energy harvesting has increased significantly in recent years. The extraction of forest energy is usually done with conventional forwarders. The productivity of extraction work is, however, quite poor due to a low material density, which results in a small load size. The objective of the study was to increase the productivity of forest energy extraction via solutions that increase the load size. The first method that was studied involved widening the load space hydraulically. The other solution was based on compressing the load with hydraulically tiltable stakes. The study was conducted as a development study. The field studies were carried out in the summer and autumn of 2011 on harvesting sites managed by Metsähallitus and Metsäliitto in the Jyväskylä region. The study material comprises a total of 139 loads. There was a significant difference in raw density between the logging residues and stump pieces for the widening and compressing load space solutions. For this reason, it does not make sense to compare the two load space solutions to each other. The analyses were based on the reported load scale tonnes. Both load space alternatives increased the load size by 20-30 per cent depending on the assortment. For logging residues, the increase in efficient hour productivity for extraction was 13 per cent and for stump pieces it was 30 per cent. With the compressing load space, the efficient hour productivity for full trees increased by 17 per cent. For logging residues, the increase was 5 per cent and for stump pieces it was 12 per cent. Compression was not a successful method for stump pieces and even for logging residues the benefits were mainly based on the increased load space. Compressing the load is mainly beneficial when extracting full trees. The project was carried out together with Osuuskunta Metsäliitto (now Metsä Group), Metsä-Multia Oy and Ponsse Oyj. The modelling work was done by Metsäteho Oy. This study shows results of Metsähallitus project “Maastokuljetuksen kehittäminen”. The project is part of the EffFibre (Value through Intensive and Efficient Fibre Supply) research and development programme coordinated by Forestcluster Ltd.
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(2016)Norway spruce (Picea abies) is nowadays generally planted on mounted sites in Finland. When compared to other cultivation methods, it has been noticed that mounding has significantly improved seedlings development and growth. However, inverting is still one of the mounding methods, which has been little examined nor height development models created in Finland. In this study the aim was to generate height development models for Norway spruce in 5-17-years old inverted sites. Two models were created both stand and tree levels. The effect of the model’s predictor variables to the height development was analyzed. Height model at stand level was also compared with the other Norway spruce height models in Finland. The study material consisted of 49 inverted Norway spruce plantations in southern Finland. Total number of sample plots were 853. With the sample plot data, available GIS-data (National Land Survey of Finland and Meteorological Institute) was also used to improve height models accuracy. GIS-data was utilized specially in the tree level model. Whole data was analyzed in SPSS-software where height models were fitted by using Generalized linear models -procedure. Both of the final height models included only significant height predictors. In the both models seedlings age, site type (Cajander 1949) and growing season’s precipitation sum were correlated positively with Norway spruce height. Broad-leaved trees height competition was also noticed to reduce height development in the both models. At the stand level model (RMSE 17 %) seedlings height development was also increased in coarse-grained soils. At the tree level model (RMSE 32,2 %) digital elevation model (DEM) derived topographic variables were correlated well with Norway spruce height. Hillside aspect decreased height development in Southwest, West and Northwest sides of the hill, where afternoon sun typically occur. Seedlings height was also poorer on topographic lowlands like lower slopes and depressions. In the tree level, height development was also decreased according to amount of competitive trees, frost damages, paludification and elevation. The inverting done a year preceding planting increased height development in the tree level model, when compared to the inverting done at the same year with planting. Model comparison at stand level demonstrate that seedlings height development was significantly better on inverted sites than on harrowed or scalpered sites. Interesting found was also that height development on inverted sites was almost identical to the mounted sites height development in the Motti-stand level simulator (Natural Resources Institute Finland). Stand level comparison indicated that Norway spruce growth and development is promising in the inverted sites and it stands comparison to the other mounding methods also. This study also proved that it is possible to utilize GIS-data (National Land Survey of Finland and Meteorological Institute) in trees height modeling.
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