Darbo objektas – Eglės žievė paimta iš lentpjūvių ir biokuro sandėliavimo vietų. Darbo tikslas – Nustatyti eglės žievės, skirtos kūrenti šildymo katilines, masės ir tūrio kitimo dėsningumus. Darbo metodai – Empirinio tyrimo metodas paremtas duomenų rinkimu – parenkant mėginius, sveriant medienos žievę ir ją džiovinant. Kiekybinis palyginimas - statistinis duomenų apdorojimas paremtas dispersine ir regresine analize. Visą tiriamąją medžiagą sudarė 68 mėginiai paimti iš lentpjūvių ir biokuro sandėliavimo vietų, o gautų rezultatų palyginimui buvo paimti duomenys iš UAB ,,Vilniaus energijos“ žaliavų apskaitos duomenų bazės (98 mėginiai). Vertinant susidariusios žievės kiekį ir jos energetinę vertę buvo pasinaudota Lietuvos nepriklausomų medienos matuotojų asociacijos duomenų baze. Darbo rezultatai – Iš surinktų duomenų buvo nustatyta, kad didžiausias santykinis medienos žievės drėgnis lentpjūvėse yra lapkričio – sausio mėnesiais (55,5 – 62,62 %), o pagal ,,Vilniaus energija“ pateiktus duomenis lapkričio – kovo mėnesiais (56,35 – 60,62 %). Pavasarį medienai pradėjus džiūti, drėgmė išgaruoja, vandens kiekis medienoje pradeda mažėti. Mažiausias žievės drėgnis lentpjūvėse vasaros laikotarpiu yra birželio – rugsėjo mėnesiais (45 – 46 %), o pagal ,,Vilniaus energija“ pateiktus duomenis mažiausias žievės drėgnis būna gegužės – rugsėjo mėnesiais (35,66 – 40,42 %). Standartinė lentpjūvėse svyruoja nuo 0,45 iki 1,53 %, o pagal ,,Vilniaus energija“ duomenis nuo 0,71 iki 5,4 %. Įdomu tai... [toliau žr. visą tekstą] / The Object of work – The Spruce bark taken from sawmills and biofuel storage places. The aim of the work – To determine the Spruce, used for burning boiler plants, bark wheight and dencity change regularities. The methods of work – The method is based on data collection – choosing the samples, drying and weighing a timber bark. Quantitative comparison – statistical data treatment in a variance and regression analysis. The investigated material were 68 samples, taken from sawmills and biofuel storage places. To compare the results data were taken from ,,Vilniaus energijos“ (limited liability company ) material accounting data base ( 98 samples). In assessing the amount of the bark and its energy value was used Independent Lithuanian Timber Measurers Association database. The results – The results shows that the biggest relative timber bark humidity in a sawmills is between November – January (55,5 – 62,62 %), according to the data from „Vilniaus energija“ November – March (56,35 – 60,62 %). In spring a timber starts to dry, the humidity level decreases, water amount in a timber starts to decrease. The lowest humidity in a sawmills is in summer between June – September (45 – 46 %), according to ,,Vilniaus energija“ data, the lowest bark humidity is between May - September (35,66 – 40,42 %). Standard humidity deflection in the sawmills varies from 0,45 to 1,53 %, according to ,,Vilniaus energija“ data, standard humidity deflection varies from 0,71 to 5,4 %... [to full text]

Spruce Bark contains several fundamental main substances; lignin, non-cellulose polysaccharides, cellulose and extractives. This undergraduate study focuses on developing a process to extract each of these components from spruce bark using a biorefinery concept, with a main focus on extracting lignin without degradation. The purpose of the Bark biorefinery concept is to contribute to a circular bioeconomy, by making use of natural resources. With extended research on the area, it will be possible to produce polymers, green chemicals and biofuel from the components in bark.  This report covers the extraction of the bark components with soxhlet extraction, Hot-water extraction, organosolv extraction and peracetic acid delignification. The extraction was made on two samples, matchstick-sized bark (MS) and 20 mesh-sized bark with a diameter of 0.8 mm (20M). The purpose was to be able to compare the efficiency of the extraction between the two samples. Afterwards, the characterisation of extracts and residue was executed with carbohydrate analysis, 2D HSQC-NMR and FTIR-analysis.  The results showed that a smaller particle size led to more efficient extractions of all components as well as more pure extract solutions. Lignin concentration determinations of samples at each step showed that a significant amount of lignin was lost prior to the organosolv extraction. Future research should look into ways to reduce this loss in order to increase the lignin yield. The findings in the FTIR and NMR analyses correlates with what could be seen in other reports, discussing similar subjects. For upscaling of this process, future research should go toward optimization of all extraction methods in order to make an upscaling of the process economically viable.

The diploma thesis deals with the issues of the spruce monocultures in the relation to the incidence of the bark beetle (Ips typographus) in the Šumava National park. The aim of the thesis is not only to unify and arrange the information, but also find out the level of knowledge about this topic among the pupils of the ninth grade of the basic school. The work also shows the level of knowledge of the pupils about the related problems and what are their opinions and suggested solutions. The thesis is divided into the theoretical and practical part. The theoretical part consists of eight chapters, that are devoted to the history of the Šumava forests, pine tree monocultures with the closer focus on the Norway spruce (Picea abies), the differences among the "natural" and "economical" forest and to the uniqueness of the Boubín primeval forest. In one of the chapters we get information about the huriccane Kyrill and its effects on the Šumava forests and followed by the information about the bark beetle calamities and about the bark beetle on its own. The last two chapters are devoted the solution of the current situation in the Šumava forests and their future perspectives. The practical part of the thesis contains mainly of the questionnaire survey proceeded among the pupils of the ninth grade of the...

The aim of the thesis was to evaluate the damage caused by bark beetle on forest stand in the district of Stribne Hute which is managed by Forest Management Tabor. Forest stands are being damaged by various harmful effects which reduce theirs ecological stability. The damage is defined as a reduction of utility value or as a damage caused by adverse effects. Spruce bark beetle (Ips typographus L.) is significant part of entomocenosis and it is being considered as the most serious pest of spruce stands. Data from 2007 - 2012 were processed, it consisted of bark beetle matter production records, evaluation of timber harvest (especially random harvest) and calculation of revenues. The price lists of average values of spruce logs KH and A/B quality was used to calculate revenues from bark beetle matter and standard quality. The comparison of revenues was used to determinate the loss caused by bark beetle. Losses were minimal due to the quantity of bark beetle which did not reach state of emergency.

Nos recherches abordent, par une approche multidisciplinaire, l’écologie spatiale et la dynamique d’invasion du ravageur de l’épicéa Ips typographus (Coleoptera :Scolytinae) en Belgique. Bien que cette espèce ne puisse pas être considérée au sens strict comme invasive en Belgique où elle est implantée depuis le milieu du 19ème siècle, de très vraisemblables introductions de souches exotiques en provenance de Russie et des Pays baltes, en font un modèle exceptionnel pour l’étude de ces processus.<p><p>Une analyse en milieu urbain, suivant des transects centre-périphérie, a d’une part suggéré l’introduction probable de ces souches exotiques et d’autre part permis d’étudier ce ravageur forestier dans un milieu qui lui est a priori défavorable. Il en résulte que, malgré un effet de la structure urbaine sur l’abondance du scolyte, sa présence a été observée partout, y compris dans les zones densément bâties du centre de Bruxelles. Cela suggère, en terme de dispersion, que cette espèce est capable d’atteindre des arbres isolés, et en terme d’infestation, que tout épicéa constitue un hôte potentiel tant en milieu forestier qu’en milieu ouvert ou urbain.<p><p>Une étape préliminaire dans l’estimation des risques liés aux invasions biologiques est d’effectuer une analyse de filière, afin d’analyser les différentes voies d’introduction et les risques liés aux pays d’origine des marchandises importées. Sur base de l’analyse de l’ensemble des sources de données statistiques disponibles, nous avons déterminé l’ampleur du commerce de grumes d’épicéa entre l’est de l’Europe et la Belgique, les modes de transport utilisés, les origines et destinations des grumes, ainsi que la variabilité de la localisation et du nombre des différents points d’entrée de ces marchandises sur le territoire belge d’une année à l’autre, depuis le début des importations en 1996. Notre analyse illustre les difficultés inhérentes à ce genre d’étude, particulièrement au niveau de la disponibilité des données à une échelle appropriée.<p> <p>Par une approche de modélisation, nous avons envisagé différents scénarios de dispersion de souches introduites d’Ips typographus afin d’estimer l’expansion de celles-ci en Belgique.<p>Notre modèle a permis de mettre en évidence l’importance de la bonne connaissance de certains paramètres biologiques caractétistiques de l’espèce étudiée (phénologie, capacité de dispersion, taux de croissance). Par ailleurs, les volumes d’importation et la localisation des points d’entrée des marchandises semblent jouer un rôle secondaire.<p><p>Enfin, nous avons utilisé des marqueurs génétiques afin d’essayer de prouver l’introduction de souches russes et baltes du scolyte de l’épicéa en Belgique. Des échantillons ont été collectés dans neuf pays européens ainsi que sur l’ensemble du territoire wallon. La structure génétique observée n’a pas permis de mettre en évidence une différenciation entre les populations de l’est et de l’ouest de l’Europe. La présence d’haplotypes communs à l’est et à l’ouest rejoint l’hypothèse d’une homogénéisation des populations en relation avec le large pouvoir de dispersion du typographe. Cependant, un grand nombre de mutations a été observé entre 2 haplotypes. Des introductions d’origines lointaines telles que la Sibérie ne sont donc pas improbables.<p><p>Les résultats détaillés de chacune de ces études sont développés dans les différents articles constituant cette thèse. La discussion générale met ceux-ci en relation et aborde les perspectives découlant de nos recherches. / Doctorat en sciences, Spécialisation géographie / info:eu-repo/semantics/nonPublished

PFAS are anthropogenic substances used in many different industrial operations and products because of their unique properties. Due to their negative impact on human health and environmental bioaccumulative characteristics different authorities have addressed the issue. In Sweden the limit is4 ng/L for four different PFAS in drinking water. Another risk to human health is elevated concentrations of toxic elements, causing Sweden to include them in the drinking water regulations withlimits such as 5 µg/L for arsenic, 25 µg/L for chromium and 5 µg/L for lead.This study is a continuation of an investigation for PFAS remediation in contaminated water by sorption to pine and spruce bark. The earlier study was a laboratory scale and implied that pine and spruce have some sorption capacity for long-chain PFAS. In this study pine and spruce bark were used as sorbent at an industrial site. The analysis was performed by weak-anion exchange extraction followed bysupercritical fluid chromatography coupled with a tandem mass spectrometer (SFC-MS/MS) and liquid chromatography coupled with tandem mass spectrometer (LC-MS/MS) for instrumental analyses of target ultra-short-chain PFAS, short- and long chain PFAS and branched PFOS isomers. An elemental analysis was executed with inductively coupled plasma mass spectrometry. The obtained results indicated removal for certain long-chain PFAS, potential for sorption of a specific ultra-short-chain PFAS and the elemental analysis implied some reduction of the chromium concentrations.

Revised; Originally published: 2006 / 5 pp. / Recent events in the forests of the Southwest, and across western North America, have prompted scientists to consider the role of climate variability in insect and disease cycles. Studies focusing on Arizona and other southwestern states point to multiple, interacting climate-related mechanisms that increase the propensity for forest mortality. Effects of insects on forests are complex, and species and site dependent. Many influences, such as drought, decreased precipitation, increased temperature, increased vapor pressure deficit, and increased stand density, combined in nonlinear and overlapping ways to create the recent and devastating pine bark beetle outbreaks in Arizona forests. Climate clearly plays a role in many, but not all, Southwest insect cycles. It is important that educators demonstrate the complexity of all of the interplaying issues, in order to communicate no false impressions of an “easy” or “one-size- fits-all” solution” for land managers.

7 pp. / Preventing catastrophic stand replacing events are best accomplished through thinning. Lower tree densities result in greater tree growth. Stands with lower tree densities have greater plant diversity. Determining stand conditions will provide a baseline for formulating a plan to improve stand conditions. Thinning around individual trees can improve individual tree health reducing the likelihood of damage from bark beetles, fire or drought.

4 pp. / This is part of a series on climate variability and forested ecosystems / Recent events in the forests of the Southwest have prompted scientists to consider the role of climate variability in insect and disease cycles. Over 70 million pine trees along with millions of other conifers died in 2002-03. Average temperature increases of 3°C enabled the MPB at those high elevations to achieve univoltine (having one generation per year) reproduction leading to previously unheard of outbreaks in white bark pine at high elevation sites in Idaho.Aspen defoliation in Arizona and New Mexico averaged ~ 20,375 acres from 1990 to 1997. A series of events has contributed to the decline of aspen since 1997.

The main objective of this study was to find factors that influence the occurrence of three-toed woodpecker (Picoides tridactylus) in Šumava at a time when the bark beetle gradation caused by Kyrill subside. The research was conducted on five transects. To prove the presence of three-toed woodpecker was opted the method of an acoustic provocation, which reliability was well proven. The hypothesis was that the three-toed woodpecker prefers the trees infested by bark beetle instead of healthy trees. Surprisingly, however, he also prefered the stands where the main attack took place several years ago. Regardless of their health status the tree- toed woodpecker preferred non-intervention stands instead of the on- going management forest. Among other factors, the exposure was applied (preferred south and west) and elevation (median, minimum altitude of about 1100 m.). Another important result is that Picoides tridactylus prefers for its food stands still alive or just dead spruce trees infested by the bark beetle. Overall, it appears that the three-toed species has narrowly defined biotope demands, which are linked to the natural spruce forest unaffected by people. The results of this study could be used to better understanding of the ecology three-toed woodpecker, eventually can help to create a...