O solo é um recurso natural essencial para os seres humanos. Porém, atualmente, as atividades humanas estão provocando a degradação do solo principalmente através da aceleração dos processos erosivos. Os estudos sobre estes processos ajudam na compreensão, interpretação e conservação do solo. Assim, este trabalho pretende estudar e datar os processos erosivos em uma voçoroca localizada na Estação Experimental de Tupi (Piracicaba SP) mediante o uso da dendrogeomorfologia. A dendrogeomorfologia é uma ciência relativamente recente que relaciona os anéis de crescimento das árvores com processos geomorfológicos permitindo a reconstrução cronológica e ocorrência dos eventos. A relevância deste estudo é conhecer o potencial desta ciência em áreas tropicais já que atualmente este tipo de estudos são escassos nestas áreas. Esta técnica foi aplicada utilizando raízes expostas de espécies do gênero Pinus sp. A datação do processo erosivo baseou-se nas mudanças no padrão de crescimento das raízes, tais como: a largura do anel, crescimento excêntrico, porcentagem do lenho tardio e densidade do lenho ocorridas após a sua exposição pelo processo erosivo. Através do estudo destas alterações determinou-se o primeiro ano de exposição da raiz e se calculou a taxa de erosão anual. Os resultados mostraram que a voçoroca está formada pela integração de dois sistemas de diferentes origens que confluem em um degrau de erosão. A abertura das voçorocas está influenciada pela presença de processos de \"piping\" na área, os quais também afetam a morfologia das raízes quando enterradas. A taxa de erosão vertical, segundo o método de GÄRTNER (2007), atingem valores entre 17,0 e 36,5 mm/ano quantificando o processo de afundamento da voçoroca; e a taxa de erosão horizontal, segundo o método de MALIK (2008), valores de 0,70 e 1,45 m/ano caracterizando o avanço longitudinal da mesma. Estes resultados são elevados se comparados com resultados obtidos em climas temperados por outros autores e similares aos publicados por BOVI (2013) na mesma área de estudo. Finalmente, a dendrogeomorfologia se corrobora como uma ferramenta de grande potencial em áreas tropicais. Os dados e informações obtidos podem se traduzir num banco de dados dendrogeomorfológicos e contribuir à expansão desta ciência no Brasil e áreas de ambientes tropicais. / Soil is a vital natural resource for humans. However today, human activities are causing soil degradation mainly by accelerating soil erosion. Studies of these processes help to understand, interpret and conserve the soil. This work aims to study and date the erosion in a gully located in the Experimental Station of Tupi (Piracicaba SP) using dendrogeomorphology. Dendrogeomorphology is a relatively new science that relates the growth tree rings with geomorphological processes allowing chronological reconstruction and occurrence of events. The relevance of this study is to know the potential of this science in tropical areas because currently this type of studies are lacking in these areas. This technique was applied using exposed roots of species of Pinus sp. The dating of the erosion process was based on the changes in the pattern of root growth, such as the width of the ring, eccentric growth, percentage of latewood and density of the wood that occur after exposure by erosion. Through the study of these changes the first year of root exposure was determined, and the annual rate of erosion was estimated. The results showed the gully is formed by the integration of two different systems that converge in an erosion step. The opening of the gully is influenced by the presence of piping in the area, which also affect the morphology of the roots when buried. The vertical erosion rate, according to the method of GÄRTNER (2007), reached values between 17.0 and 36.5 mm/year quantifying the deepenning process of the gully; and horizontal erosion rate according to the method of MALIK (2008), values of 0.70 and 1.45 m/year characterizing the longitudinal advancement of the gully. These results were high compared with results obtained in temperate climates by others authors, and similar to those published by BOVI (2013) in the same site. Finally, dendrogeomorphology demonstrates great potential as a tool in tropical areas. The data and information obtained can be translated into a dendrogeomorphological database and contribute to the expansion of this science in Brazil and areas of tropical environments.

Este trabalho tem como objetivo avaliar a viabilidade técnica e econômica da utilização da madeira serrada de pinus, de terceira classe de qualidade, na produção de componentes para vedação vertical destinados à habitação social, empregando a técnica da laminação vertical cavilhada. Para o desenvolvimento da pesquisa, foi realizado um estudo de caso, que teve como unidade de análise o assentamento rural Fazenda Pirituba, localizado na região Sudoeste do estado de São Paulo. A viabilidade técnica da proposta foi avaliada a partir da produção e experimentação por meios de ensaios exploratórios, de modelos em escala 1:1 e a viabilidade econômica, por sua vez, foi estudada através da simulação de diferentes cenários de produção dos componentes, considerando todas as etapas da cadeia produtiva da habitação em madeira. Os resultados obtidos com os ensaios exploratórios, indicaram a possibilidade de que a proposta seja tecnicamente viável. Contudo, a simulação de cenários de produção indicou que, para que a mesma seja viável economicamente, torna-se necessária a introdução de políticas públicas que interfiram especialmente na dinâmica da produção de madeira serrada, desde a etapa de plantios, através do estímulo à reposição florestal em pequenas propriedades rurais e uso sustentável dos recursos florestais, passando pela produção, através da introdução de relações de trabalho mais justas, até a comercialização, a partir da expansão do mercado consumidor de produtos de madeira de plantios florestais / This work has as objective to evaluate the technique and economic feasibility of the utilization of the third class sawed wood of pinus in the production of components for vertical seal for social housing, using the vertical wooden dowel lamination technique. To the development of the research, was realized a study of case that had as unit of analysis the Fazenda Pirituba rural settlement, located in the southwestern portion of the state of São Paulo, Brazil. The technique feasibility of the proposal was evaluated through the production and experimentation by exploratories assays in models made in 1:1 scale and the economic feasibility, was studied through the different scenes of production of the components simulation, having considered all the stages of the productive chain of the habitation made by wood. The gotten results had indicated the possibility that the proposal is technically feasible. However, the scenes of production simulation had indicated that: to the economic fesibility of the proposal, becomes necessary the introduction of public politics that intervene especially in the dinamic of the sawed wooden production, since the stage of plantantion, by the stimulation to the forest replacement in small properties and sustainable use of the forest resources, passing through the production, by the introduction of the works relationship more justs, until the commercialization, from the expansion of the consuming market of the products made by wood from the planted forests

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-07-26T16:32:18Z No. of bitstreams: 1 2016 - Marcelly Alves da Silva.pdf: 1109436 bytes, checksum: cf0918f898aa3347f3dda630016df417 (MD5) / Made available in DSpace on 2016-07-26T16:32:18Z (GMT). No. of bitstreams: 1 2016 - Marcelly Alves da Silva.pdf: 1109436 bytes, checksum: cf0918f898aa3347f3dda630016df417 (MD5) Previous issue date: 2016-02-26 / SILVA, Marcelly Alves da. Using of calcium and magnesium lignosulfonate in mixtures with phenol-formaldehyde in particleboard manufacturing. 2016. 33 p. Dissertation (Master in forest and Environmental Sciences). Instituto de Florestas, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, 2016. The purpose of this study was to evaluate the feasibility of using calcium and magnesium lignosulfonate (LS) in the production of Pinus caribaea var. caribaea particleboard panels, used pure and in mixtures with phenol-formaldehyde (FF). It was determined the basic and apparent density of the wood, as well as the physical and chemical properties of adhesives. In order to evaluate the effect of FF replaced by LS on the physical and chemical properties, panels were produced with different concentrations of these adhesives. The experiment consisted of two phases. The first phase was performed under temperature of 160?C and pressing time of 10 mitutes with the following compositions: 100% FF, and LS substitutions in the proportions of 20, 40, 60, 80 and 100%, with three replications each. In the second phase, the first phase of the three treatments with lower performance in the mechanical properties were tested at a temperature of 180?C and to 7 minutes. The results of basic and apparent wood density were 0.54 and 0.60 g/cm?, respectively. In the second stage the temperature increased and decreased of the pressing time were not sufficient to consolidate the panel, becoming not possible to analyze the results of this phase. In respect to the thickness swelling and water absorption, increases in the proportion of lignosulfonate in the mixture also raise up these values. The substitution of the phenol-formaldehyde adhesive of lignosulfonate was satisfactory in attendance the specific norm for mechanical properties by 80%. The lignosulfonate showed efficiency in the use as an adhesive in the production of particleboard in mixtures with phenol formaldehyde, suggesting that this is an alternative of the use of synthetic adhesives. / SILVA, Marcelly Alves da. Utiliza??o de lignosulfonato de c?lcio e magn?sio em misturas com fenol-formalde?do na produ??o de pain?is aglomerados. 2016. 33 p. Disserta??o (Mestrado em Ci?ncias Ambientais e Florestais). Instituto de Florestas, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, 2016. O objetivo deste estudo foi avaliar a viabilidade da utiliza??o do lignosulfonato de c?lcio e magn?sio (LS) na produ??o de pain?is aglomerados de Pinus caribaea var. caribaea, na forma pura e em misturas com fenol-formalde?do (FF). Foram determinadas a densidade b?sica e aparente da madeira, bem como as propriedades f?sicas e qu?micas dos adesivos. De modo a avaliar o efeito da substitui??o de FF por LS sobre as propriedades f?sicas e qu?micas, foram produzidos pain?is com diferentes concentra??es desses adesivos. O delineamento experimental foi constitu?do de duas fases. A primeira fase foi realizada sob a temperatura de 160?C e tempo de prensagem de 10 minutos, com as seguintes composi??es: 100% de FF, e as substitui??es por LS nas propor??es de 20, 40, 60, 80 e 100%, com tr?s repeti??es cada. Na segunda fase, os tr?s tratamentos da primeira fase com desempenho inferior nas propriedades mec?nicas foram testados na temperatura de 180?C em tempos de prensagem de 5 e 7 minutos. Os resultados m?dios da densidade b?sica e aparente da madeira foram de 0,54 e 0,60g/cm?, respectivamente. Na segunda fase, o aumento da temperatura e a diminui??o do tempo de prensagem n?o foram suficientes para consolidar o painel, n?o sendo poss?vel analisar os resultados desta fase. Com rela??o ao inchamento em espessura e absor??o de ?gua, ? medida que aumentou a propor??o de lignosulfonato na mistura elevaram-se tamb?m esses valores. Em at? 80%, a substitui??o do adesivo fenol-formalde?do por lignosulfonato foi satisfat?ria no atendimento a NBR 14810-2 (ABNT,2013) para propriedades mec?nicas. O lignosulfonato apresentou efici?ncia na utiliza??o como adesivo na produ??o de pain?is aglomerados em misturas com fenol-formalde?do, evidenciando que esta ? uma alternativa ? utiliza??o de adesivos sint?ticos.

A possibilidade de utilização da técnica de colorimetria para obter informações relevantes das peças de Pinus é uma excelente alternativa, uma vez que o colorímetro é um equipamento de fácil manuseio e rápida aquisição de dados, e o uso de madeira de florestas plantadas é crescente no Brasil. O objetivo desta pesquisa foi gerar modelos de regressão para estimativa da densidade aparente e das propriedades mecânicas (resistência e módulo de elasticidade) em função de parâmetros colorimétricos. Nesta pesquisa, 403 amostras de Pinus sp. foram caracterizadas de acordo com o sistema CIE L*a*b*, utilizando um colorímetro Konica Minolta. A densidade aparente, a resistência à compressão paralela às fibras e o módulo de elasticidade na compressão paralela às fibras das 403 amostras também foram determinados, de acordo com as premissas do Anexo B da norma brasileira ABNT NBR 7190 (1997). Foi proposto um modelo de regressão multivariável e testado utilizando análise de variância (ANOVA), ao nível de significância de 5%, para estimar as três propriedades citadas, em função dos parâmetros colorimétricos e do número anéis de crescimento (quantidades de lenho inicial e lenho tardio). Os resultados indicaram que a madeira apresenta coloração branco-amarelada, pois possui valor de luminosidade (L*) superior a 54. A pigmentação amarela (b*) é a principal responsável pela formação das cores no gênero Pinus. A análise de correlação entre cor, número de lenhos (Nle) e densidade revelou que apenas a luminosidade, o número de lenhos e a interação desses fatores afetaram significativamente os valores de densidade. A diminuição da luminosidade e o aumento na quantidade de lenhos implicam um aumento significativo nos valores de densidade da madeira. A análise de correlação entre cor, número de lenhos e módulo de elasticidade revelou que apenas o número de lenhos afetou significativamente os valores do módulo de elasticidade. O aumento no número lenhos implica aumento significativo no módulo de elasticidade na compressão paralela às fibras. A análise de correlação entre cor, número de lenhos e resistência à compressão paralela às fibras mostrou que apenas os fatores L*, a*, b* e as interações L*·b*, a*·b*, afetaram significativamente os valores da resistência. A interação entre os fatores L* e b* implicou na redução dos valores da resistência à compressão paralela às fibras. A técnica de colorimetria mostrou-se adequada para a estimativa de propriedades físico-mecânicas da madeira. / The possibility of using the colorimetric technique to obtain relevant information of Pinus pieces is an excellent alternative, since the colorimeter is an equipment of easy handling and quick data acquisition, and the use of wood from planted forests is growing in Brazil. This research aims to generate regression models to estimate the wood density and mechanical properties (strength and modulus of elasticity) as a function of colorimetric parameters. Here, 403 pieces of Pinus sp. have been characterized according to the CIE L*a*b* system using a Konica Minolta colorimeter. The apparent density, the compression parallel to the grain strength and the modulus of elasticity in the compression parallel to the grain of the 403 samples were also determined, according to the assumptions of Brazilian standard code ABNT NBR 7190 (1997). It was proposed a multivariate regression model and tested using analysis of variance (ANOVA), at 5% significance level, to estimate the density, the compressive strength and the modulus of elasticity as a function of the colorimetric parameters and the number of tree growth rings (earlywood and latewood). Results indicated that the wood has a yellowish-white coloration, with a value of brightness (L*) higher than 54. The yellow pigmentation (b*) is the main responsible for the color formation of the genus Pinus. Correlation analysis among color, number of tree growth rings (Nle) and density showed that only the brightness, the number of tree growth rings and the interaction of these factors affected significantly the values of density. Decreasing in brightness and increasing in the number tree growth rings implies a significant increasing in wood density values. Correlation analysis among color, number of tree growth rings and modulus of elasticity showed that only the number of tree growth rings affected significantly the values of modulus of elasticity. Increasing in the number tree growth rings implies a significant increasing in the modulus of elasticity. Correlation analysis among color, number of tree growth rings and compression parallel to the grain strength showed that only the factors L*, a*, b* and the interactions L* ·b*, a*· b*, affected significantly the values of strength. The interaction between the factors L* and b* implied the reduction of the values of the compression parallel to the grain strength. The colorimetric technique was appropriated for estimative of physico-mechanical properties of wood.

The background to the large-scale planting of Pinus contorta in northern Sweden is reviewed with an account of the distribution and characteristics ofPi nus contorta within its natural range in western North America. The threatsto successful planting of exotics are discussed in relation to the historicalbackground. Attention is also drawn to parasitic fungi which are infectingPi nus contorta in western Canada, and to the potential threat they representto the indigenous Pi nus sylvestris in Sweden.During a seven-year-period 100 provenances of Pi nus contorta have been investigatedannually with respect to different kinds of damage, primarilythose by parasitic fungi. The study indicates that damage to Pi nus contortaprimarily occurs during the first ten years after planting. Northern provenancesof Pi nus contorta are generally more resistant to pathogens than southernprovenances. Weather damage occurs almost every year among trees ofsouthern and coastal provenance. Even trees of northern provenance have sufferedfrom weather damage due to temperature oscillations during shoot elongation.Severe weather damage is a predisposing factor to infection by secondarypathogens primarily.Gremmeniella abietina. There is a minor correlation betweensevere weather damage and Phacidium infestans. Even northern provenancesof Pinus contorta are infected by Phacidi um infestans in high altitude standsin northern Sweden. Snow b light infection is, however, of a minor importanceto lodgepole pine than to Scots pine due to the rapid early growth of the former.The most productive plants of both Pinus contorta and Pinus sylvestrisare attacked by Phacidi um infestans. Plants not infected by snow b light havea lower height growth than those infected.Severe infection by Gremmeniella abietina has been recorded after voleattack, even among northern provenances of lodgepole pine. So far Pinus contortahas mainly been infected by the same fungi as Pinus sylvestris, with the |exception of Melampsora pinitorqua and Lophodermella sul ci gena. Pinus contorta iis, however more susceptible to infection by Gremmeniella abietina in connec- !tion with vole damage, depending on the more severe injuries to lodgepole pinethan to Scots pine.So far vole damage has been the most severe threat to Pinus contorta innorthern Sweden. Voles prefer lodgepole pine to Scots pine providing vole populationis moderate. At times of high vole populations even Scots pine suffersdamage. Voles attack Pinus contorta even 14 years after planting. The differencein frequency of vole damage among provenances strongly decreased with increasedvole population and repeated attacks from year to year.Tree tilting was first noted five to eight years after planting on sites exposedto strong winds and severe icing.In the central parts of northern Sweden most provenances of Pinus contortaare less attacked by pathogens than the indigenous Pinus sylvestris, and inorthern provenances of lodgepole pine are remarkably productive in thenorthernmost site, despite a relatively high frequency of Phacidium infestar^.Later investigations indicate, however, more severe damage to Pinuscontorta with increasing latitude and altitude in northern Sweden. / digitalisering@umu

Effects of stand type on ground lichen height and species richness in boreal forests.   P. contorta as an alternative to P. sylvestris in terms of providing a suitable habitat   Maria Johansson     Abstract     Lichen-rich forests are essential to reindeer but up to 50 % of the lichen-rich areas in Sweden have been lost since the 1950s. Ground lichens thrive in pine-heaths and with an increasing area of plantations of the non-native tree species Pinus contorta, as an alternative to the native P. sylvestris, it is important to investigate if P. contorta can provide such an optimal habitat to ground lichens. The purpose of this study was to assess if forest characteristics, such as tree density, canopy cover and production capacity, affect the abundance and growth of five lichen species (Cladonia rangiferina, C. arbuscula/mitis, C. stygia, C. stellaris and Cetraria islandica) and whether these characteristics differ between forests dominated by P. contorta and forests dominated by P. sylvestris. Fieldwork was conducted in Norrbotten and Västerbotten on sample plots previously used by the Swedish National Forest Inventory (SNFI). The statistical analysis was based on data collected from 22 sample plots, 11 of each forest type, visited during July and September 2015. No statistical significant differences were found between forest characteristics of the two forest types, and none of the forest characteristics were found to relate to lichen height. Forest age did not seem to have an effect on ground lichens, while both canopy cover and production capacity were found to negatively relate to the proxy for lichen biomass as well as the abundance of the most common lichen species, C. rangiferina and C. arbuscula/mitis. The result suggests that a shadier canopy as well as a higher production capacity contributes to a reduced distribution of ground lichens.   Keywords: Ground lichens, Pinus contorta, Pinus sylvestris, forest characteristics, forestry, reindeer husbandry

Annotation Il y a plusieurs périodes quad les radioactivité des radionuclides dans l��environement sont grandi . Ces périodes s’ont trouvé à cause des explosions nucléaires et d’avarie de la station atomique de Chernobyl. Les radionuclides se retrouvent dans les plantes avec les emisions d’atmosphere par les surterres partes, avec le fluide de sol par les system de la rasines. Les radionuclides s’accumulent dans les plantes. L’accumulation des radionuclides dans les plantes dépende de la pollutions, du sol type dominant, des particularités chimiques et fisiques des radionuclides, de la forme chimique des radionuclides, du type des plants, des particularités climatiques. Le pin (Pinus sylvestris L.) est très étendu en Lituanie. Très souvent les maladies des champingion et des moisissures attaquent cet type d’arbre. C'est pourquoi nous choisisons le pin (Pinus sylvestris L.), qui est attaqué des maladies des champingion et des moisissures pour les recherches. Nous avons ramassé et traité tels échantillons: du sol, des mousses, des branches, des rasines, des aiguilles, du boi. Dans notre échantillons nous avons déterminé les activités des 226Ra, 232Th, 40K, 137Cs et les facteurs de transfert des radionuclides dans le systèm sol – arbre. Dans les 27 échantillons de bois nous avons déterminé les colonies des champingions. Mais le excitateur de moisissure (Heterobasidion annosum) as déterminé seulement en un échantillon de bois. Nous avons estimé quel est l’influence des... [to full text]

Magistro darbe lyginama vieno paprastosios pušies (Pinus sylvestris L.) klono skirtingų lajos dalių sėklinių palikuonių, augančių Višakio Rūdos bandomuosiuose želdiniuose, genetinė įvairovė remiantis DNR žymenimis ir kokybiniais bei kiekybiniais požymiais. Darbo objektas – paprastosios pušies (Pinus sylvestris L.) sėklinių palikuonių želdiniai iš skirtingų lajos dalies sėklų (viršutinės, vidurinės, apatinės). Darbo metodai – genetinė įvairovė tirta atliekant želdinių kiekybinių ir kokybinių požymių analizę bei jų DNR polimorfizmo tyrimą. Darbo rezultatai. Fenotipinių požymių tyrimai parodė, kad 24 m amžiuje, viršutinės lajos dalies sėkliniai palikuonys pasižymi ženkliai didesniu išlikimu, bet esminiai nesiskiria savo kiekybinių ir kokybinių požymių įvairove nuo apatinės lajos dalies palikuonių. Gali būti, kad fenotipinių požymių įvairovei atsiskleisti trukdo nevienodas medžių išlikimas, kur esant mažesniam išlikimui, susidaro nevienodi tarpai tarp medžių, galėję įtakoti didesnę erdvinę įvairovę radialiniam prieaugiui. 6 chloroplasto DNR(cpSSR) lokusų DNR polimorfizmo tyrimai parodė, kad viršutinės lajos dalies sėklinių palikuonių genetinė įvairovė yra ženkliai didesnė nei vidurines ir apatinės lajos dalių sėklinių palikuonių. Iš 30 skirtingų cpSSR tipų (tėvinių genotipų) 18 buvo aptikti viršutinės lajos dalies palikuonyse, tuo tarpu vidurinėje dalyje – 8, o apatinėje - 10 .Visi 5 proc. savidulkinių individų aptikti tarp apatinės ir centrinės lajos dalies palikuonių (18 vnt.)... [toliau žr. visą tekstą] / The genetic diversity of the progeny from different parts of Scots pine crown of a single clone by quantitative and qualitative traits and DNA polymorphism was investigated in the work of master science. Object of the work - 24 years old progeny from different parts of Scots pine crown of a single clone. The aim of the study - to compare the diversity of quantitative and qualitative traits and DNA polymorphism of24 years old progeny from different parts of Scots pine crown of a single clone by using cpSSR DNA markers. Methods of the work - Survival, stem diameter, stem straightness, flowering, cone yield, barktype,condition,the beginning of activegrowth and other parameters of the seedling progenies were evaluated. The genetic diversity was assessed at six cpDNA loci by the aid of cpSSRs. Study results. The results showed, that the survival of the progeny from the middle and the bottom of the crown was much lower than from the top. However, there were not any significant differences nor in the other traits neither between the variances of the progeny from the different parts of the crown. A reason could be that owing to low survival of the bottom and middle progeny, the remaining trees grew in a wider spacing and this uneven spacing between the treatments disturbed the comparison. cpSSR markers revealed much greater haplotype and allele diversity of the progeny from the top of the crown. Selfing rate was 5; background pollination 50; as much as 28 of the progeny from the... [to full text]

För tallen finns många alternativa slutanvändningsområden, och kraven på virket varierar. Några egenskaper som har stor betydelse är stamrakhet, grengrovlek, grenvinkel och om det finns sprötkvist eller ej. Kvalitetsförsämringen i Sydsveriges tallskogar kan vara ett allvarligt problem och härör bl.a. till ökad produktion och rationaliseringar inom skogsbruket. Lönsamhet har varit målet, men har det skett på bekostnad av kvalitet? För att närmare belysa frågan om förekomsten av tall av god kvalitet syftar denna studie till att bedöma rotstockar i konventionellt skötta och stamkvistade bestånd samt deras potential att växa in i värdefulla klasser eller sortiment. Fältstudien är avgränsad till Bergslagen. I mätningarna har endast rotstock (upp till 3,4 m i längd) av träden bedömts, huruvida de har potential att hålla klass 1-kvalitet, sortiment stamblocks-kvalitet eller sortiment rotstock-kvalitet vid en brösthöjdsdiameter av 320 mm. Andelen rotstockar ≥ klass 1 uppskattades i de stamkvistade bestånden bli 72-94 %, då skötseln också syftat till en värdeökning.  Andelen rotstockar ≥ klass 1 i de konventionellt skötta bestånden uppskattades bli 46-56 %. Med stor sannolikhet kommer ingen av dem dock få växa in i de värdefullaste klasserna. Vanligaste nedklassningssorsakerna är för många kvistar och ibland även i kombination med krök i de konventionellt skötta bestånden samt långkrök i de stamkvistade bestånden. I rapportens teori avhandlas olika sortiment och kvalitetsklasser, och sedan undersöks kvalitetsdanande faktorer bl.a. ekologiska förutsättningar och olika skötselåtgärder. En hög röjningsstyrka kan t.ex. resultera i en grövre diameter på grenar. Likaså har sen röjning inverkan på den grövsta grenens diameter, då den minskar. Det finns alltså en potential att erhålla god virkeskvalitet av tall i våra skogar. Detta är möjligt genom aktiv skötsel, att hålla täta förband, genom att gallra ut lågkvalitativa stammar och stamkvistning. Raka tallar ur vilka kan man utvinna ett högt sågutbyte är och kommer att vara en värdefull resurs i framtiden. / In Sweden the quality of Scots pine (Pinus sylvestris) saw timber has decreased. It is especially due to increased labour cost that has led to rational and effective forest management. This study investigated the quality of Scots pine and the potential to produce high quality stems in 9 stands in Bergslagen, Sweden. Two different stand types were investigated: Pruned stands and conventional managed stands. The outcome was a high percentage of valuable stems in the pruned stands (72-94 %), and 46-56 % in the conventional managed stands. It is possible to produce high quality timber of Scots pine with active management, for example by pruning and careful selection of stems in thinnings.

Den här studien är en uppföljning av föryngringsresultatet efter maskinell sådd av contorta ( Pinus contorta Dougl. var. latifolia Engelm.) i Härjedalen. Efter tre växtsäsonger uppgick det totala antalet såddplantor till 3 700 per ha och antalet huvudplantor uppgick till 1 800 per ha. Andelen nollytor uppgick till 2 %. Det var ingen skillnad i föryngringsresultat mellan låg och hög altitud. Generellt gav maskinell sådd av contorta ett tillfredsställande föryngringsresultat. På mindre bördig mark var såväl det totala antalet såddplantor som antalet huvudplantor högre än på bördigare mark. / Mechanical regeneration by seeding of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in the province of Härjedalen in Sweden was studied. After three growing seasons the total number of seedlings were 3 700 per ha and the number of main seedlings were 1 800 per ha. 2% of the sample plots had no plants within 3 m. No difference could be found between objects on high and low altitudes. In general mechanical seeding gave satisfactory regeneration. On low fertile soils the total number of seedlings as well as the future main seedlings was higher than on more fertile soils.