Browsing by discipline "Metsien ekologia ja käyttö"
Now showing items 41-60 of 167
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(2018)Hieskoivu (Betula pubescens) on Suomen kolmanneksi yleisin puulaji, ja sen osuus puuston tilavuudesta on noin 12 %. Soistuneilla kivennäismailla ja turvemailla viihtyvä hieskoivu sopii parhaiten kuitu- ja energiapuun tuottamiseen, koska sen tukit eivät yleensä täytä vanerin tai sahatavaran laatuvaatimuksia. Kansainväliset ja kansalliset uusiutuvan energian käyttötavoitteet pyrkivät nostamaan erityisesti metsähakkeen käyttöä Suomessa. Hieskoivun korkea lämpöarvo ja metsähakkeen tuorepoltosta saadut lupaavat tulokset voisivat laskea logistiikka- ja varastointikustannuksia, jolloin hakkeen käyttö energiantuotannossa olisi kannattavampaa. Tutkielman tavoitteena oli laatia kuorellisen kokonaistilavuuden biomassamallit hieskoivulle. 11 koepuun aineisto mitattiin Hyytiälän tutkimusasemalla huhtikuussa 2017. Puun rungon ja oksien tilavuus määritettiin pätkä kerrallaan veteen upottamalla. Koepuista mitattiin lisäksi manuaalisesti pätkien pituudet sekä ristiläpimitat oksista ja rungon katkaisukohdista. Rungon sekä rungon ja oksien yhteenlaskettujen pohjapinta-alojen korrelaatioita vertailtiin rungon suhteellisilla korkeuksilla. Biomassamalleja varten koepuille tehtiin koepuukohtainen lineaarinen regressioanalyysi, jonka avulla estimoitiin elävän latvuksen kokonaistilavuuden lineaarista riippuvuutta selittävistä tunnuksista. Mallien muuttujat muunnettiin logaritmimuotoon, jotta muuttujien väliset pienet epälineaarisuudet saatiin korjattua. Selittävänä muuttujana oli ensin pelkkä elävän latvuksen rajan läpimitta, ja sen jälkeen myös elävän latvuksen pituus. Koepuukohtaisten mallien lisäksi laadittiin yksi kaikki koepuut sisältävä malli. Lopuksi omasta aineistosta laadittiin vielä kokonaistilavuuden malli, jossa käytettiin samoja tunnuksia kuin Laasasenahon koivun läpimittaan ja puun pituuteen perustuvassa tilavuusyhtälössä. Koepuiden runkojen sekä rungon ja oksien yhteenlaskettujen pohjapinta-alojen välillä oli korkea lähellä yhtä oleva korrelaatio suhteellisilla korkeuksilla tarkasteltuna. Ainoastaan puun latvassa korrelaatiot olivat alle 0,9. Oksat sisältävien pohjapinta-alojen korrelaatiot olivat pelkkää runkoa suurempia puun latvassa. Jokaisen koepuukohtaisen elävän latvuksen biomassamallin korjattu selitysaste parani ja suhteellinen keskivirhe pieneni, kun malleissa oli mukana selittävänä tekijänä läpimitan lisäksi elävän latvuksen pituus. Koko aineistoon perustuvan mallin korjattu selitysaste oli 0,998 ja suhteellinen keskivirhe 7,8 %. Pelkälle rungolle laaditun mallin kertoimet olivat hyvin lähellä Laasasenahon tilavuusyhtälön vastaavia kertoimia. Rungon biomassamallin selitysaste oli 0,999 ja suhteellinen keskivirhe 4,5 %. Omaan aineistoon perustuva malli antoi rungolle keskimäärin 4 % suuremman tilavuuden verrattuna Laasasenahon tilavuusmallilla laskettuun runkotilavuuteen. Kokonaisbiomassan mallin selitysaste ja keskivirhe olivat samat kuin pelkälle rungolle laaditussa. Kokonaistilavuuden mallilla laskettu tilavuus oli keskimäärin 8 % pienempi Repolan koivun biomassamalliin verrattuna. Tutkimustulosteni mukaan pienellä koepuuaineistolla saadaan laadittua biomassamalleja, joilla on korkea selitysaste ja pieni suhteellinen keskivirhe, kun hieskoivun biomassaa selitetään läpimitalla ja pituudella. Hieskoivujen runkomuodot olivat samansuuntaisia erikokoisilla puilla, ja oksien sekä rungon yhteenlasketuilla pohjapinta-aloilla oli suhteellisilla korkeuksilla tilastollisesti merkitsevä korrelaatio, minkä perusteella hieskoivun biomassan pystysuuntainen jakaantuminen on erikokoisten puiden välillä samankaltaista. Pohjapinta-alojen korkeat korrelaatiot vahvistavat johtopäätöstä siitä, että runkokäyrätekniikkaa hyödyntämällä saadaan käyttökelpoisia tuloksia aikaan jo muutamalla koepuulla.
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(2020)Downy birch (Betula pubescens Ehrh.) is by far the most common tree species in Finland when considering stem count. The num-ber of the downy birches are almost double compared to pine (Pinus sylvestris). Downy birch is not very demanding of its sur-rounding and it grows in both dry and wet places in forests, marshes, shores and abandoned fields. Downy birch grows in all areas in Finland except the northernmost Lapland. Compared to Downy birch silver birch (Betula pendula) is smaller, short-lived and the appearance is more varied. Downy birch can grow up to 20 meters high and 70 to 90 years old. Downy birch has not been exceedingly popular tree in Finland, and it is mostly used as an energy wood. Downy birch and silver birch are not separated in commercial use. The aim for this study was to develop cumulative model for above ground volume and biomass for downy birch with 15 tree sample. Diameter, length and weight were manually measured from each section of the sample tree stems. Weight of branches were measured for every stems section. Volume and weight of each stem section and branches were measured by sinking them into water. Relative taper curves were calculated for each sample tree and with those the general taper curve was calculated. From stem and branch volumes separate volume curves were calculated. General volume curves for were calculated based on the separate curves. With those curves different cumulative whole tree volume curves were created. In addition to volumes, also densities for stem sections and branches were calculated. With those and volume curves biomass model can be calculated Calculated taper curves differed from Laasasenaho’s taper curves mostly on the base of the stem but above 10 % relative height the taper curves behaved similarly. Whole tree volumes were calculated with nine different methods and the results were com-pared to Hoppi’s and Repola’s equations and measured volumes. Equations where the tree height was the only explanatory factor gave much more varied results than those equations which also took the diameter in consideration. Smallest relative standard deviations were 4,1 %, 4,2 % and 4,6 %. Smallest standard deviations of the volume were 8,3 l, 7,4 l and 7,4 l. These equations used tree height and diameter. Hoppi’s and Repola’s equations gave relative standard deviations of 5,7 % and 12,7 % and stand-ard deviations of the volume were 10,7 l and 9,4 l, respectively. Similar comparisons were not done with biomass model because reliable results of the branch and stem densities were available only from three sample trees. The equations presented here are different than previous models because of the cumulative nature- Only other downy birch model was Hoppi’s model. Cumulative approach makes it possible to calculate volume (or biomass) from any relative height range and previous models do not offer that possibility. Other models give out the volume or the biomass of the whole tree (or stem). Comparison with the other models demonstrates that it is possible to create models that work well at the local level with very few sample trees. Comparisons with Repola’s model shows that result can be generalized well. Results verifies the assumption that the proportions of different size trees behave consistently.
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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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(2020)As climate change is already affecting our planet, it is urgent to ensure adequate support to the most vulnerable communities, sectors, and ecosystems to adapt to the changing climate. The scale of the financial resources that are expected to flow into climate change adaptation is likely to lead to a stronger emphasis on measuring and verifying results as there is international consensus that climate change adaptation interventions should be results-based. However, currently, there is no scientific nor political consensus over what effective adaptation is and how it should best be measured. As a result of this, efforts are needed to improve both methodologies and guidance for assessing adaptation. Through a systematic review of projects funded by the Adaptation Fund, I categorize 30 adaptation projects. The act of cataloguing adaptation measures and further analysing their similarities and differences produces insights in two main areas: identifying how projects have been designed to address and assess adaptation effectiveness; and enhancing understanding on the role of trees and forests in adaptation initiatives. I analyse the ways these projects are planned to assess their effectiveness using three main research indicators: reducing vulnerability and increasing adaptive capacity; reducing exposure; and sharing of lessons-learned and increasing climate change adaptation science. This includes studying the defined expected project results, indicators and baselines stated in projects’ results frameworks. The project proposals are further studied to gain understanding on how trees and forests are used to address and assess adaptation. The projects are analysed to test whether projects that address climate change adaptation similarly have also similarities in assessing effective adaptation. In order to do that the projects are categorized into four categories based on their approach: 1. ecosystem-based adaptation projects; 2. engineered or sectoral adaptation projects; 3. community-based adaptation projects; and 4. small-scale funding modality projects. I focus on exploring the objectives, types, and limitations of adaptation metrics used in assessing adaptation but also provide recommendations. Since the first years of the Adaptation Fund the projects have developed in regard to assessing their expected results with a few exceptions to the general trend. The national and regional implementing entities were more often struggling to set proper results frameworks. Trees and forests had a more prominent role than would be assumed by the limited number of projects classified as forestry projects as 80% of the projects included trees and/or forests as part of activities, outputs, outcomes, or indicators. It can be concluded that the studied projects had differences in addressing and measuring of adaptation. Effective adaptation was mostly framed to contribute to reducing vulnerabilities that include measures to increase adaptive capacity. Significantly less expected outcomes and outputs were set to reduce exposure to climate change impacts. Interestingly successful adaptation was also framed as sharing of lessons-learned or communicating other findings to a wider audience, and also to measure channelling of funding, project management, or social inclusion aspects.One of the key findings is that how the project is to address adaptation also influences how effective adaptation is to be measured and verified leading to different typical strengths and challenges in assessing effectiveness.
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(2019)Forest structural and compositional diversity is of great importance for forest biodiversity, functioning, and response to disturbances. The purpose of this research was to examine how human impact has affected the structural-compositional diversity of mature pine-dominated boreal forest in boreal Fennoscandia. For this a new approach was used, based on the classification of tree sizes by the diameter at breast height (dbh) and tree species, resulting in a new variable, the diametric-species, the variation of which describes the structural-compositional diversity of the forest. This variable was used to compare the structural-compositional diversity among three forest classes with different degree of human influence (near-natural, selectively logged and managed forest), using rarefaction as the main tool of analysis, complemented by analyses based on common diversity indices. For comparison, the rarefaction analysis was also done for the tree species classification. The results of the rarefaction analysis of the diametric-species showed that the near-natural forest was the most diverse and the managed forest the least diverse. The analysis solely on tree species showed no significant differences among the forest classes of different human impact. The Shannon diversity index showed no significant difference between the forest classes for the diametric-species and only tree species classifications, but the Simpson index found a slight difference between the selectively logged and managed forest classes for the diametric-species classification. Furthermore, the Sorensen index detected a difference among forest classes for diametric-species and failed to detect one for the tree species classification, which supports the rarefaction findings. We conclude that forest management has had a negative impact on forest compositional and structural diversity in mature Scots pine forests. The analysis also shows that the diametric-species classification can be a useful tool for forest diversity analysis and comparison
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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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(2020)Removal of sub-canopy trees is a type of forest management practice, mainly employed to minimize subsequent harvesting costs. Such management activities, however, are a source of disturbance in boreal forests, including those of Finland. The removal of understory trees causes mechanical damage to trees, with coniferous trees, such as Scots pine, being particularly susceptible. The resulting injuries significantly enhance emissions of biogenic volatile organic compounds (BVOCs) to the atmosphere, thereby modulating its gas composition. BVOCs are involved in plant growth, reproduction and defence, while functioning as communication media within and between plants. These plant-released compounds have high chemical reactivity with large mass emission rate from vegetation into the atmosphere; therefore, they are major determinants of atmospheric gas composition with important implications for the Earth’s atmosphere and climate. Despite the wealth of knowledge on this topic, our understanding of how forest management activities affect BVOC emissions is limited. Uncertainty remains as what the impact of sub-canopy removal is on BVOC emissions from forest trees over a long timescale. This is important since such management activities are common, with equal or potentially even larger impact on BVOC emissions both in the short- and long-run. To address this knowledge gap, I test the impacts of sub-canopy removal on the emissions of BVOCs from a Scots pine stand in a boreal forest. In so doing, I also consider the effects of temperature, soil moisture, and photosynthetically active radiation on the concentrations of these compounds above the canopy. The research sheds light on the complex and intertwined effects of the sub-canopy removal and environmental variables on the stand-level BVOC emissions. The results have implications regarding how forest management practices, and more broadly anthropogenic activities, influence forest-atmosphere interactions. Finally, the research provides promising avenues for future research.
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(2018)This thesis represents a thorough study on association between tree height and phloem anatomy of a tree. Phloem is one of the major components of the vascular system of a plant as it facilitates the transportation of products of photosynthesis from source to sink. In this research, a coniferous tree species, Picea abies (L.) Karst, which is commonly known as Norway spruce, was carefully examined as a model plant. Specifically, the correlation between tree height and the anatomical features of cells that constitute each compartment of a tree stem (i.e., outer bark, phloem, cambium, and xylem, which is composed of sapwood and heartwood) was investigated, aiming to help understand the phloem anatomy and elucidate the underlying mechanisms that govern the secondary tree growth. In particular, the variations of an array of anatomical properties of wood, such as cell number, cell size, structural dimensions, were measured at different height levels to establish the axial profiles for these anatomical features. Notably, the number of tracheid and sieve cells in the stem of Norway spruce was found to increase with tree height and water stress gradient. While the size of tracheid cell in radial direction exhibited no distinct axial pattern, a decrease in sieve cell size from the middle part of the living crown towards the top of the crown in both radial and tangential direction was observed. Also, the widths of wood layer, phloem and periderm exhibited dependence on tree height. This dissertation consists of a literature review relevant to this study, the detailed experimental methods involved in this work, a summary of the results and discussion, and a conclusion chapter.
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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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(2020)Electronic commerce (E-commerce) has become an international phenomena nowadays. Especially in China, due to the country’s size, large population and culture, the consumption-driven economic growth plays a more fundamental role than in many other countries, which gives higher requirements for the development of modern logistics. The rapid development of Chinese e-commerce, has made online shopping a very important part in people’s daily life as it is cheaper and more convenient than to buy things from traditional stores. At the same time, the Chinese government gives strong support to E-commerce in its economic development strategy. In March 2015 an E-commerce idea called Internet Plus (Internet+) was officially announced by the Chinese Prime Minister as an important government business strategy in the future economic development plan. The idea does not only aim to develop a new type of economics, but also to improve the traditional economics. The new strategy can decrease enterprises’ cost and increase overall operating efficiency. Behind the high development speed of the e-commerce, logistics is a very important factor to ensure the success of the online business and it is necessary to realize which factors under E-commerce Logistics takes the biggest part and has the most weight among all logistics features. In this study, I will concentrate on Internet+ Logistics, which derived from E-commerce Logistics. Evaluate the logistics performance of 364 online none timber forest products (NTFPs) stores from Alibaba online shopping mall names Tmall. The study can be seen as complete and conceptual, both in the academic and the practical field. By using entropy weight method, Topsis analysis and cross analysis, I analyze the weights of different levels indexes in Internet+ Logistics performance and also get total scores and ranking of sample online stores, in order to understand the important factors and the development trend in Internet+ Logistics. My study reveals, that some indexes such as service can largely influence the performance of online store logistics, which are the most important elements of Internet+ Logistics. The proposed framework enriches the theory of network marketing and gives directions to business owners to make improvements on the logistics quality of their online stores.
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(2018)Tausta Suomessa tuotettiin vuonna 2016 noin 5,9 milj. m³ kuusisahatavaraa. Kuusta (Picea abies) käytetään pääosin rakentamiseen. Siitä valmistettavia tuotteita ovat liimapuu, sisä- ja ulkoverhouslaudat, rakennusten rungot ja koolaukset. Sahatavaran laatu vaikuttaa siitä valmistettavan tuotteen ominaisuuksiin. Sahatavaralle on määritelty laatuluokat, jotka ovat US, V, VI ja VII. Laatuun eniten vaikuttavat ominaisuudet ovat oksaisuus, halkeamat, muotoviat ja lyly. Sahatavaran ominaisuuksille on määritelty enimmäismäärät ja -koot eri laatuluokissa. Tuottajien vaatimukset raaka-aineelle ovat erilaisia, koska sahatavaraa käytetään hyvin erilaisissa tuotteissa. Kuusisahatavaraa käyttävien yritysten laatuvaatimuksia ei ole tähän mennessä kattavasti selvitetty. Tavoite ja menetelmät Tutkielman tavoite oli selvittää kuusisahatavaran jatkojalostajien asettamat mitta- ja laatuvaatimukset. Tutkimuksessa haastateltiin 20:ta yritystä, jotka sijaitsevat Pirkanmaalla ja sen lähialueilla. Yritykset jaettiin heidän valmistamansa tuotteen mukaan viiteen luokkaan, jotka ovat liimapuu, runkorakenteet, ulkoverhouslaudat, sisäverhous- ja lattialaudat sekä listat ja puusepäntuotteet. Yrityksiltä kerättiin taustatiedot sekä heidän asettamansa vaatimukset raaka-aineelleen. Kysymyksillä selvitettiin jatkojalostajien käyttämät sahatavaran laatuluokat, heidän käyttämänsä mitat, sahatavaran eri ominaisuuksien merkitsevyydet, terveoksaisuuden tärkeyttä, sydäntavaran käyttöä, lujuusvaatimuksia, raaka-aineen kosteussuhdetta ja kuusisahatavaran käyttöä tulevaisuudessa. Aineistosta laskettiin tilastollisia lukuja ja vastauksia mallinnettiin järjestysasteikkomallilla. Tulokset ja johtopäätökset Aiempaa kirjallisuutta mukaillen sahatavaran laatu- ja mittavaatimukset vaihtelivat eri jatkojalostajaluokkien välillä. Korkein laatuvaatimus oli listojen ja puusepäntuotteiden valmistajilla. Seuraavaksi korkein vaatimustaso oli muiden höylätuotteiden tuottajilla. Pienimmät laatuvaatimukset olivat rakennusten runkojen valmistajilla ja liimapuun tuottajilla. Lähes puolet yrityksistä ilmoitti tilaavansa sahatuottoista (ST) sahatavaraa. Merkittävimmät ominaisuudet sahatavarassa keskimäärin olivat oksien koko ja laatu sekä halkeamat, muotoviat ja oksien määrä. Yritykset halusivat pääosin terveoksaista sahatavaraa ja yli puolet vastasi tarvitsevansa sydäntavaraa. Sahatavaran mittojen osalta yritykset tilasivat pitkää sahatavaraa. Yritykset katkovat pitkän sahatavaran ja hyödyntävät raaka-aineen mahdollisimman tehokkaasti. Kuusisahatavaran tilatut paksuudet ja leveydet määräytyvät jatkojalosteen vaadituista mitoista. Höylätuotteiden valmistajat tilaavat myös lopputuotteita paksumpia ja leveämpiä mittoja, mikä johtuu sahatavaran halkaisusta. Tutkimuksen tulokset antavat tietoa sahatavaran tuottajille. Huomioimalla sahatavaran tilaajan vaatimukset, sahatavaran tuottajat pystyvät parantamaan kilpailukykyään.
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(2019)Julkinen rakentaminen on yksi tärkeimmistä kokonaisuuksista, joista kunnissa päätetään. Puurakentaminen on viime aikoina yleistynyt julkisessa rakentamisessa erityisesti koulu- ja päiväkotihankkeissa, joten tässä tutkimuksessa julkista puurakentamista käsitellään puukoulu- ja päiväkotihankkeiden avulla. Tässä tutkimuksessa tarkastellaan kunnallisen päätöksenteon taustalla vaikuttavia tekijöitä puukoulujen ja -päiväkotien rakennuspäätösten taustalla sekä myönteisiin että kielteisiin puurakentamispäätöksiin yhdistettäviä merki-tystekijöitä. Tutkimuksen keskeinen tutkimusongelma muodostuu julkisen puurakentamisen edistämisestä kunnallisessa päätöksente-ossa. Tutkimus toteutettiin julkisen puurakentamisen edistämisen näkökulmasta. Tutkimusaihetta taustoitetaan raporttiin sisällytetyllä kirjallisuuskatsauksella kansallisen puurakentamisen nykytilaan ja puun ominaisuuksiin rakentamisessa. Tämän tutkimuksen tieteenfilosofiset lähtökohdat ovat pragmatistiset ja käsittelytavaksi valittiin laadullisen menetelmän hyödyntämi-nen ja vertaileva mutta kriittinen näkökulma. Tutkimusongelmaan ratkaisua haettiin tapaustutkimuksen ja teoriaohjaavan lähestymisen keinoin. Otantatutkimukseen valittiin 20 kuntaa tai kaupunkia, joissa oli viimeisen viiden vuoden aikana päätetty uuden koulun tai päi-väkodin rakentamisesta tai rakennushanke oli tutkimuksen aikaan keskeneräinen. Kyselytutkimuksella muodostettiin kuva kunnan päätöksentekijöiden käsityksistä puurakentamisen nykytilasta sekä puurakentamiseen liittyvistä asenteista kunnissa. Kyselytutkimuk-sella kerättyä aineistoa täydennettiin Imatran kaupungin virkamiesjohdolle suunnatuilla haastatteluilla. Aineisto analysoitiin laadullisesti luokittelun ja erittelyn keinoin pyrkimyksenä muodostaa ilmiöstä mahdollisimman yhtenäinen ja totuudenmukainen kuvaus. Tutkimuk-sen teoreettinen perusta rakentuu puurakentamisen nykytilaa, kunnallista päätöksentekoa ja puuraaka-aineen ominaisuuksia rakenta-misessa käsittelevän kirjallisuuskatsauksen varaan. Pragmatistiselle tutkimukselle tunnuksenomaisesti myös tutkija osallistuu tulosten tarkasteluun ulottaen oman kokemuspohjansa tutkimusaiheeseen. Puurakentamisen asenneilmapiiri kunnissa on myönteinen. Valtaosa vastaajista suhtautui myönteisesti sekä puurakentamiseen että puun käytön lisäämiseen julkisessa rakentamisessa. Puu mielletään ympäristöystävälliseksi ja terveelliseksi rakennusmateriaaliksi, jonka uskotaan tarjoavan ratkaisun esimerkiksi julkista rakennuskantaa vaivaaviin sisäilmaongelmiin. Puurakentamisesta kaivataan kunnissa kuitenkin lisää tietoja erityisesti puurakentamisen kustannuksista, toteutuneiden julkisten puurakennushankkeiden rakennus-teknisistä yksityiskohdista ja rakentamisprosessista yleisesti. Kunnissa arvostetaan puurakentamisen positiivista imagoa sekä sen terveysvaikutuksia ja sisäilmaa edistäviä ominaisuuksia. Kunnissa halutaan lisäksi tukea kotimaan taloutta ja paikallista elinkeinoa. Vaikka vastaajat kokivat puurakennuksen turvalliseksi ja ilmaisivat arvostavansa puun käytännöllisiä, ekologisia ja terveyttä edistäviä ominaisuuksia, he totesivat puurakentamiseen ja puuhun rakennusmateriaaliina liittyvän runsaasti ennakkoluuloja ja asennekapeikkoja ihmisten keskuudessa. Erityistä huolta ihmisten keskuudessa aiheuttavat puurakennuksen paloturvallisuus ja puuhun rakennusmateri-aalina liitettävät homeongelmat. Lisäksi myös puurakentamisen osaaminen koetaan kunnissa riittämättömäksi. Asiantuntijoiden hyö-dyntäminen koettiin puurakentamista edistävänä tekijänä päätöksenteossa. Tutkimus osoitti tarpeen kokonaan ulkopuolisen tahon tuottamalle objektiiviselle asiantuntijatiedolle, jonka keinoin voidaan vaikuttaa ihmisten keskuudessa esiintyviin vallitseviin virheellisiin käsityksiin ja ennakkoluuloihin puurakentamisesta. Puurakentaminen on suurten julkisten rakennushankkeiden osalta Suomessa vielä alkuvaiheessa ja suotuisan toimintakulttuurin raken-taminen vielä kehitysasteella. Julkisen sektorin asema rakentamisen markkinoilla on keskeinen, sillä mitä enemmän kunnissa rakenne-taan toimitiloja, päiväkoteja ja kouluja puusta, sitä enemmän se luo kysyntää myös yksityisillä markkinoilla. Tutkijalle muodostuneen käsityksen mukaan kunnissa on myönteinen tahtotila rakentaa puusta. Toiminnassa olisi kuitenkin otettava askel eteenpäin ja siirryttä-vä voimakkaammin hankkeiden myötä konkretiaan. Haasteita puurakentamisen yleistymiselle aiheuttavat päätöksentekijöiden keskuu-dessa esiintyvät ennakkoluulot ja asennekapeikot, jotka vaikuttavat puurakentamisen hankepäätöksiin.
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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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Kasvin stressin määrittäminen lehtitasolla klorofyllifluoresenssin ja reflektanssi-indeksien avulla (2018)Tutkimuksen tavoitteena oli selvittää kasvien stressitekijöiden vaikutuksia kasvin klorofyllifluoresenssiin ja reflektanssiin. Tutkimuksessa havainnoitiin, voidaanko eri bioottisia ja abioottisia stressitekijöitä mitata kasvin erittämästä klorofyllifluoresenssista ja reflektanssista, kun stressattuja lehtiä mitataan spektrofotometrillä. Tarkoitus oli myös selvittää olisiko stressin vaikutusta kasviin mahdollista havaita kasvin erittämässä spektrissä jo ennen kuin stressistä on olemassa paljain silmin näkyviä merkkejä. Kasvien stressiä on mahdollista mitata kasvien ”vihreydellä”, jota pystyy mittaamaan kaukokartoitusmenetelmin satelliiteista ja lentokoneesta käsin. Lehvästötason mittauksissa käytetään hyväksi mm. NDVI-indeksiä (Normalized Difference Vegetation Index), jossa vertaillaan eroja kasvin heijastamassa punaisessa ja infrapunaisessa spektrissä. NDVI-mittausten haittapuolena on kuitenkin niiden hidas reaktiokyky kasvien kokemaan stressiin. Tämän takia on kehitetty sekä klorofyllifluoresenssimenetelmä, että PRI-indeksi, joiden on mahdollista löytää eroja kasvin heijastamassa fluoresenssissa ja reflektanssissa kasvin ollessa pienenkin stressin alaisena. Tässä tutkimuksessa vertaillaan eri reflektanssi-indeksien (PRI, SR, NDVI) ja klorofyllifluoresenssin käyttömahdollisuuksia stressitasojen havaitsemisessa. Tulokset analysoitiin tilastollisin menetelmin käyttäen Spearmanin järjestyskorrelaatiokerrointa ja laskenta suoritettiin R-Studio ja SPSS-ohjelmilla. Aineisto mitattiin neljässä eri kohteessa kesän 2017 aikana. Jokaisessa kohteessa valittiin yhdeksästä kahteentoista koekasvia, joista kustakin mitattiin neljä lehteä. Mitattavien lehtien tuli olla täysikasvuisia, sekä olla puun valoisimmalla puolella. Lehdet mitattiin spektrofotometrillä pimeässä tilassa mittausten standardoimiseksi ja jotta ulkoa tuleva valo ei häiritsi mittauksia. Spektrofotometrillä mitattiin lehden vakaan tason fluoresenssi, sekä lehden reflektanssi. Samoista koepuista mitattiin myös lehtien absorbanssia, valon läpäisevyyttä, kaasujenvaihtoa, sekä maksimikvanttisaantoa. Klorofyllifluoresenssin 685nm ja 740nm taajuusalueiden suhteella kyettiin havainnoimaan typen määrää lehdissä ja PRI-indeksin huomattiin olevan hyvä työkalu natriumin määrän havainnoimiseen kasvien lehdissä. Lehtien stressin määrän huomattiin joissain koetilanteissa korreloivan fotosynteesin määrän kanssa jo stressin ollessa hyvin pientä. Tulokset indikoivat, että klorofyllifluoresenssin mittaaminen olisi varteenotettava menetelmä kasvien hyvinvoinnin mittaamiseen jo ennen kuin kasvissa on paljain silmin nähtäviä merkkejä stressistä. Tässä tutkimuksessa tehdyt havainnot pätevät kasveissa vain lehtitasolla, mutta lisätutkimuksissa voisi selvitä, voiko tuloksia yleistää myös kasvi- ja lehvästötasolle.
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(2019)Wood reserves and growth in Finland’s forests are greater than ever. The 12th National Forest Inventory (NFI12) 2014–2017 measured the volume of trees at 2.5 billion cubic meters and the annual growth rate at 107 million cubic meters. The results showed that forest regeneration was well managed, but there was room for improvement in the care of seedlings and young stands. The late tending of seedling stands increased about 11% compared to the previous NFI11 inventory in 2009–2013. Costs of tending seedling stands and for first thinning in young stands are high. Harvesting costs for thinning from below methods including forest haulage constitute over half of all expenses. Reducing forest management costs is one of the most important goals in Finnish forestry. Using a boom-corridor thinning method would improve the cost-effectiveness of harvesting timber and wood bioenergy. The purpose of this study was to examine the time required for boom-corridor thinning methods and productivity of the mechanical first thinning in young pine forests in the existing harvesting technologies and well as to compare the productivity and costs of harvesting to the traditional practice of thinning from below. The study was performed for a project of the Natural Resources Institute Finland (LUKE) that studied boom-corridor thinning as a harvesting method for the first mechanical thinning of young Scots pines. The boom-corridor thinning development project was implemented in 2017–2018 as part of the rural development plans for North Karelia, Central Finland, and Northern Finland in 2014–2020. The objective was to sustainably manage forest resources and support renewable energy production. Study was made of Konnevesi test stands’ time study material and the tree database. The study compared the time required by three thinning methods: boom-corridor thinning in which the corridor location was tagged beforehand, boom-corridor thinning in which the operator selected the corridor location, and traditional thinning from below. A Ponsse Beaver harvester equipped with a Ponsse H6 harvester head was used in the Konnevesi test stands to thin by single tree harvesting. Time study and comparative research shows that boom-corridor thinning was more productive and economical than traditional thinning from below. For boom-corridor thinning method M2, in which the location of a corridor was tagged, the productivity E₀ was 18% higher than the traditional thinning from below method, when the average density of the removed trees were18 % bigger than harvesting from below. For boom-corridor thinning method M3, in which the operator chose the location of a corridor, the productivity E₀ was 4,5% lower than the traditional thinning from below method, when the average density of the removed trees was 26% lower than the other thinning methods. For boom-corridor thinning methods M2 and M3, productivity E₀ was 6,7% higher than the traditional thinning from below method. The statistical analysis shows that the differences between the harvesting methods correlate with the stem size, which was bigger in the boom-corridor thinning methods than the thinning from below, especially in the treatment M2.The boom-corridor thinning method M2 unit costs €/m³ were 15% lower than those of the traditional thinning from below method. For boom-corridor thinning method M3, joint average unit costs €/m³ were 5% higher than those of traditional thinning from below method M1 and 20 % higher than boom-corridor thinning method M2. The study concluded that boom-corridor thinning is a productive harvesting method worth developing for the first thinning of young forests. Using boom-corridor thinning methods will reduce costs of first thinning forests significantly. Compared to previous research, the main results of this study were similar, with a 16% increase in productivity. Other studies suggest productivity could be doubled with technology developed for boom-corridor thinning.
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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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