Browsing by discipline "skoglig ekologi och resurshushållning"

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.

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.

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.

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.

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.

Birch wood discoloration called pith flecks is caused by a birch stem miner Phytobia betulae Kangas (Diptera: Agromyzidae), which is a very common species in Finland in both silver and downy birch (Betula pendula Erhr. and Betula pubescens Roth). There is a strong positive correlation between fast tree growth and abundance of P. betulae. Female flies lay their eggs into the young upper shoots of the birch, and the larvae start to move downwards in the stem in the newly differentiated xylem layer under the bark and phloem. The larvae form long vertical tunnels which the tree fills with brown parenchyma cells. In tangential cutting the tunnels look like brown stripes, but in cross-sectional cutting they are like small brown spots in the annual growth rings of the stem. The larval tunnels don’t affect the wood strength, but they cause an aesthetic disadvantage especially for veneer and furniture industry. So far the only reliable and accurate method for counting the larval tunnels has been to cut the trees, take experimental discs from breast height and count the tunnels by using stereomicroscope. The tree trials for forest tree breeding are extensive. To study the genetic susceptibility of birch to P. betulae a quicker and more feasible method would be needed for measuring the larval tunnels of P. betulae. The aim of this study was to investigate: 1) whether it is reliable to count the pith flecks by naked eye and how equivalent the different measuring methods are, and 2) if it would be possible to use an increment core for measuring pith flecks from a growing tree. Genetic susceptibility of silver birch families to P. betulae was studied from forest tree breeding field trials in which the larval tunnels were counted by naked eye. The research data was collected from the experimental field trials of Natural Resources Institute Finland in Parikkala and Punkaharju. Reliability of different measuring methods was studied in young trees by comparing the amount of larval tunnels counted by naked eye, from one sector of the disc and from an increment core to the amount of tunnels counted by using stereomicro-scope. The clones were ranked by their susceptibility to P. betulae from the lowest to the highest by using every method of the test. In aged trees with big diameters the larval tunnels were counted from one vertical slice and from one sector of the experimental disc. When studying the open-pollinated progeny of B. pendula with southern and central Finnish provenances the birch families were ranked by their susceptibility to P. betulae. In that data the larval tunnels were measured by naked eye. The order of the families was compared before taking the growth effect into account and after that, when the most and least susceptible families could be separated from the others. The results of the study revealed that the amount of the larval tunnels of P. betulae can be counted pretty reliably by naked eye and the counting can be done from one part of the experimental disc. Cutting the trees is still demanded, because the results of the increment cores were far too unreliable. In case of aged trees both counting the tunnels from one vertical slice and from one sector of the disc proved to be useful methods. When studying the birch families the results showed that fast tree growth alone does not increase the birch susceptibility to P. betulae, but there are also other factors affecting it. Heritabil-ity in the progeny trials on former agricultural land varied from 0.18 to 0.34. Measuring the pith flecks from large breeding data is too slow and laborious, and a quick method for counting the larval tunnels would be needed e.g. if a genetic marker would be searched for the trait in the future.

Tiivistelmä – Referat – Abstract Finland has one of the highest percentage of peatlands in the world, so peatlands have inevitably been taken into cultivation use. Agricultural peatlands however generate a significant amount of greenhouse gas emissions, especially carbon dioxide (CO2) and nitrous oxide (N2O). Thus, agricultural usage of peatlands is considered one of the most unfavorable uses of land for the climate. Peatlands have been drained in order to improve food services, which in turn negatively affects other ecosystem services. Some of the ecosystem services can be restored by rewetting the land. If rewetting is combined with paludiculture, the land’s production services will not be lost. The goal of this thesis was to compare the greenhouse gas emissions and the carbon footprints of two paludicultural products’ life cycles. The compared products were cattail insulation board and common reed seedbed. The intent was to produce comparable data on different options for the paludiculture of agricultural peatlands. The data obtained from the life cycle assessment of the products was compared to similar non-paladiculture products, rock wool insulation board and horticultural peat. The material was reviewed with the life cycle assessment method following the ISO 144040 standard, but the work was limited only on climatic effects. Based on the analysis, key sources of climatic effect in the product system were identified and means to reduce them were considered. The intent was to calculate the carbon footprint and to identify where in the life cycle the emissions were generated. After this, the portion of agricultural peatlands in in the life cycle’s environmental effects was estimated. The material for this thesis was collected from scientific literature and life cycle assessment databases (ecoinvent v.3). The material of peatlands and other parts of the process were collected from studies made around the world in the boreal and temperate zone. A model was assembled based on the material, which included all phases of the paludicultural product’s life cycle and their effects on the climate with regards to carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), The emissions in a paludicultural product’s life cycle are mostly generated during its cultivation and processing. The carbon footprint of both paludicultural products was most likely negative, so they slowed down climate change. Based on the study, the most benefit was achieved by moving the cultivation of barley from agricultural peatlands to mineral soil and replacing it with paludiculture. By using paludiculture, it’s possible to reduce greenhouse gas emissions of agricultural peatlands, but it won’t achieve carbon neutrality. The study had a significant amount of uncertainty, so further studies are recommended especially in Finland.

Pohjois-boreaalisessa metsässä puun lahoaminen on hidas prosessi, joka vaikuttaa merkittävästi metsän rakenteeseen, dynamiikkaan ja kasvuolosuhteisiin. Hajotessaan lahopuu tuottaa vettä ja hiilidioksidia ja tarjoaa ravinteikkaan kasvupaikan kasveille, pieneliöille ja mikrobeille. Metsikön rakenteen muutoksen ja hiilen kierron ymmärtämiseksi tulee lahopuudynamiikkaa tutkia luonnontilaisessa metsässä. Tämän tutkimuksen tavoitteena oli selvittää kuolleen pysty- ja maalahopuun lahoamisnopeutta luonnontilaisessa metsässä. Lahopuut luokiteltiin viiteen laholuokkaan niiden lahoamisasteen perusteella ja laskettiin puiden viipymäaika kussakin laholuokassa. Lahoamisnopeus määritettiin lahopuun siirtymisellä näiden luokkien välillä iän funktiona. Lisäksi laskettiin pystyyn kuolleiden puiden kaatumistodennäköisyys vertaamalla pystyssä olevien lahopuiden määrää kaikkiin lahopuihin ja suhteuttamalla se viipymän pituuteen. Tulosten esittelyä varten laholuokista muodostettiin kolme eriasteisesti lahonnutta luokkaa: Tuore lahopuu, keskinkertaisesti lahonnut ja merkittävästi lahonnut. Lahopuuaineistoa kerättiin kolmesta paikasta; Värriön ja Maltion luonnonpuistoista sekä Venäjän Kazkimista. Koealoja oli yhteensä 48 kappaletta. Koealoilta mitattiin kaikki rinnankorkeusläpimitaltaan yli 10 cm kuolleet puut. Pystypuista kairattiin lustonäyte, maapuista sahattiin kiekkonäyte, joista puiden kuolinvuodet ajoitettiin dendrokronologisin menetelmin. Yhteensä 519 rungosta saatiin määritettyä kuolemisesta kulunut aika. Puulajeina oli mänty (Pinus sylvestris), kuusi (Picea abies) ja koivu (Betula spp.). Lahoamisnopeutta tarkasteltiin luomalla graafinen kuvaaja ajan funktiona, jonka avulla voitiin ennustaa kuinka kauan mittaustilanteessa löydetty lahopuusto lahoaa. Männyn lahoaminen näyttäytyi merkittävästi hitaampana kuin kuusen ja koivun. Männyn pystylaho-puista lahosi 95 % totaalisesti tai siirtyi kolmanteen, merkittävästi lahonneeseen laholuokkaan 210 vuodessa, kuusella vastaava lahoaminen kesti 85 ja koivulla 105 vuotta. Männyn maapuiden vastaa-va 95 % osuus vei 140 vuotta, kuusella 85 ja koivulla 105 vuotta. Tulosten perusteella pohjoisboreaa-lisessa metsässä pystyynkuolleiden puiden vuosittainen kaatumistodennäköisyys on pieni, vaihdellen 0 - 3 % välillä. Hidas, jopa 200 vuotta kestävä lahoamisprosessi on merkittävä tekijä pohjoisboreaalisessa metsässä ja vaikuttaa pitkällä aikavälillä kokonaisvaltaisesti ympäristönsä rakenteeseen ja dynamiikkaan.

Kuusen puuosa jakautuu kosteaan pintapuuhun ja kuivaan sydänpuuhun. Kuusipölkkyä sorvatessa syntyy viilumatto, jonka alkupää on kosteaa pintapuuviilua ja loppupää kuivaa sydänpuuviilua. Viilut leikataan arkeiksi ja lajitellaan kosteusluokkiin, jotta eri kosteussuhteisia viiluja voidaan kuivata niille sopivalla ajonopeudella ja oikeassa lämpötilassa. Eräällä vaneritehtaalla on viilun valmistusprosessiin lisätty uusi vaihe, jossa märkiä viiluja esikuivataan ennen varsinaista kuivausta märkäpuristamalla. Tämän vaiheen tarkoituksena on tasata kosteuden hajontaa ja laskea viilujen kosteussuhdetta. Esikuivaus nopeuttaa viilun kuivaamiseen käytettävää aikaa ja vähentää varsinaisen kuivauksen energian kulutusta. Tutkimuksen tavoitteena oli kirjallisuuden perusteella selvittää, mitkä asiat kuusen rakenteessa vaikuttavat sorvattujen viilujen kosteusjakaumiin. Laboratoriokokeiden tavoitteena oli selvittää, kuinka märkäpuristusolosuhteiden hallinta ja kosteusluokkien sekoittaminen vaikuttavat esikuivauksen tulokseen. Tavoitteena oli minimoida märkäpuristuksen jälkeinen kosteuden hajonta ja poistaa viiluista mahdollisimman paljon vettä jo esikuivauksessa, jotta niiden kuivaaminen varsinaisessa kuivauksessa olisi tehokkaampaa. Tutkimusta varten näytteet otettiin vaneritehtaan prosessista ja kokeet tehtiin laboratoriossa. Esikuivaukseen käytettiin laboratoriokäyttöön tehtyä yksivälistä puristinta, jossa viilupinkkoja puristettiin 50 kappaleen erissä. Viilut punnittiin yksitellen ennen ja jälkeen esikuivauksen. Lisäksi kaikki viilut kuivattiin absoluuttisen kuiviksi ja punnittiin kuivina. Näin saatiin selville poistuneen veden määrä, kosteussuhde ennen esikuivausta sekä sen jälkeen ja kuiva-tuoretiheys. Kirjallisuuskatsauksen mukaan kosteusjakaumia viiluissa aiheuttaa sydän- ja pintapuun vaihtelu viiluissa. Kosteusjakaumiin vaikuttaa myös oksien korkeampi tiheys. Koska kuusen oksat ovat tiheämpiä kuin runkopuu, ne eivät sido itseensä yhtä paljon kosteutta kuin oksattomat kohdat. Laboratoriokokeissa havaittiin, että märkäpuristusolosuhteiden hallinta vaikuttaa esikuivauksen tulokseen. Myös kosteusluokkien sekoittamisella havaittiin olevan vaikutusta esikuivauksen tulokseen. Johtopäätöksien mukaan märkäpuristusolosuhteiden hallinnalla voidaan saavuttaa esikuivausprosessissa parempia kuivaustuloksia ja energiasäästöjä. Märkäpuristusolosuhteisiin voidaan vaikuttaa tehtaalla märkävaraston logistiikkaa muuttamalla ja tarvittaessa myös laitteistolisäinvestoinnein. Tutkimuksessa jo tehtyjen märkäpuristusolosuhdemuutoksien vaikutuksia viilun rakennemuutokseen esikuivauksen jälkeen olisi tarpeen tutkia viilun saannon parantamiseksi.

A diameter distribution describes the size distribution of a forest and is used, for example, in forest planning. Stand characteristics can also be produced without a diameter distribution, but the diameter distribution allows utilization of tree-level models in the calculation of stand level variables and improves the estimation accuracy. In this thesis estimation methods for diameter distribution prediction were compared and the suitability of the methods and materials evaluated by using error indices. The two comparative diameter distribution estimation methods used in this study were the k most similar neighbor method (k-MSN) and the prediction of diameter distribution using the theoretical distribution model: Weibull-distribution. Both study methods utilised laser scanning-, field plot- and harvester measurement data collected from mature Norway spruce dominant forests in Southern Finland. When the k-MSN method is applied, the measured diameter distribution and stand characteristics of the nearest neighbor were imputed to the target grid of the stand. Stand characteristics were used for the prediction of Weibull-distribution parameters. Weibull parameters were estimated by modelling and by parameter recovery. Field and harvester plots were used as a reference data for the k-MSN. The suitability of the Weibull distribution for the description of the diameter distribution was evaluated by estimating the diameter distribution directly on the harvester data of the corresponding region. Maximum likelihood estimation and prediction of the Weibull-distribution were applied. As a result of the suitability testing, the Weibull distribution is seen as suitable for describing the diameter distribution of a mature, even aged, stand. With the maximum likelihood method and parameter recovery, the produced diameter distribution corresponded appropriately with the measured diameter distribution. The results of the k-MSN show that the imputation of diameter distribution gave the most accurate prediction of diameter distribution. Harvester or field plots gave nearly as accurate results and are both suitable for diameter distribution prediction