Mould growth on coated wood is today a genuine challenge for house owners. Environmentally sound wooden facades with long service lives and acceptable appearance are desired. The objective in this ...study was to investigate the accumulated mould growth on 13 different wood substrates with 3 surface coating systems by identifying the factors that contribute to the variation and to predict future performance. A generalized linear mixed model was fit to the data with the analysis showing that coating and exposure time both had highly significant influences on mould growth. Further, wood substrate was significant, but comparatively less than coating and exposure time. A smaller coefficient for mould coverage in the beginning of the exposure period gave the panels with one of the coating systems, BAP, a delay in mould growth, and the extrapolated values for years 6-12 indicate a longer aesthetic service life than panels with the two other coating systems. Coated heartwood as wood type was less susceptible to mould growth than coated mixed wood and coated sapwood. Acetylated pine as wood substrate and aspen as wood species had lower resistance to mould growth than the other wood substrates and wood species, respectively.
Background and Aims Wood formation in trees represents a carbon sink that can be modified in the case of stress. The way carbon metabolism constrains growth during stress periods (high temperature ...and water deficit) is now under debate. In this study, the amounts of non-structural carbohydrates (NSCs) for xylogenesis in black spruce, Picea mariana, saplings were assessed under high temperature and drought in order to determine the role of sugar mobilization for osmotic purposes and its consequences for secondary growth.MethodsFour-year-old saplings of black spruce in a greenhouse were subjected to different thermal conditions with respect to the outside air temperature (T0) in 2010 (2 and 5 °C higher than T0) and 2011 (6 °C warmer than T0 during the day or night) with a dry period of about 1 month in June of each year. Wood formation together with starch, NSCs and leaf parameters (water potential and photosynthesis) were monitored from May to September.Key Results With the exception of raffinose, the amounts of soluble sugars were not modified in the cambium even if gas exchange and photosynthesis were greatly reduced during drought. Raffinose increased more than pinitol under a pre-dawn water potential of less than –1 Mpa, presumably because this compound is better suited than polyol for replacing water and capturing free radicals, and its degradation into simple sugar is easier. Warming decreased the starch storage in the xylem as well the available hexose pool in the cambium and the xylem, probably because of an increase in respiration.Conclusions Radial stem growth was reduced during drought due to the mobilization of NSCs for osmotic purposes and due to the lack of cell turgor. Thus plant water status during wood formation can influence the NSCs available for growth in the cambium and xylem.
•Pretreated eucalyptus wood gave higher bio-oil yield than original eucalyptus wood.•Contents of ketones and acids in bio-oil were lowered by hydrothermal pretreatment.•Hydrothermal pretreatment ...significantly enhanced levoglucosan content in bio-oil.•Hydrothermal pretreatment improved fuel quality of bio-oil.
Eucalyptus wood powder was first subjected to hydrothermal pretreatment in a high-pressure reactor at 160–190°C, and subsequently fast pyrolyzed in a fluidized bed reactor at 500°C to obtain high quality bio-oil. This study focused on investigating effect of hydrothermal pretreatment on bio-oil properties. Hemicellulose and some metals were effectively removed from eucalyptus wood, while cellulose content was enhanced. No significant charring and carbonization of constituents was observed during hydrothermal pretreatment. Thus pretreated eucalyptus wood gave higher bio-oil yield than original eucalyptus wood. Chemical composition of bio-oil was examined by GC/MS and 13C NMR analyses. Bio-oil produced from pretreated eucalyptus wood exhibited lower contents of ketones and acids, while much higher levoglucosan content than bio-oil produced from original eucalyptus wood, which would help to improve thermal stability of bio-oil and extract levoglucosan from bio-oil. Hydrothermal pretreatment also improved bio-oil fuel quality through lowering water content and enhancing heating value.
For the first time, two types of highly anisotropic, highly transparent wood composites are demonstrated by taking advantage of the macro‐structures in original wood. These wood composites are highly ...transparent with a total transmittance up to 90% but exhibit dramatically different optical and mechanical properties.
Aim
European temperate forests have lost dead wood and the associated biodiversity owing to intensive management over centuries. Nowadays, some of these forests are being restored by enrichment with ...dead wood, but mostly only at stand scales. Here, we investigated effects of a seminal dead‐wood enrichment strategy on saproxylic organisms at the landscape scale.
Location
Temperate European beech forest in southern Germany.
Methods
In a before–after control–impact design, we compared assemblages and gamma diversities of saproxylic organisms in strictly protected old‐growth forest areas (reserves) and historically moderately and intensively managed forest areas before and a decade after starting a landscape‐wide strategy of dead‐wood enrichment.
Results
Before enrichment with dead wood, the gamma diversity of saproxylic organisms in historically intensively managed forest stands was significantly lower than in reserves and historically moderately managed forest stands; this difference disappeared after 10 years of dead‐wood enrichment. The species composition of beetles in forest stands of the three historical management intensities differed before the enrichment strategy, but a decade thereafter, the species compositions of previously intensively logged and forest reserve plots were similar. However, the differences in fungal species composition between historical management categories before and after 10 years of enrichment persisted.
Main conclusions
Our results demonstrate that intentional enrichment of dead wood at the landscape scale is a powerful tool for rapidly restoring saproxylic beetle communities and for restoring wood‐inhabiting fungal communities, which need longer than a decade for complete restoration. We propose that a strategy of area‐wide active restoration combined with some permanent strict refuges is a promising means of promoting the biodiversity of age‐long intensively managed Central European beech forests.
Wood Buffalo National Park is located in the heart of Dénesųłıuné homelands, where Dene people have lived from time immemorial. Central to the creation, expansion, and management of this park, Canada ...'s largest at nearly 45, 000 square kilometers, was the eviction of Dénesųłıuné people from their home, the forced separation of Dene families, and restriction of their Treaty rights. Remembering Our Relations tells the history of Wood Buffalo National Park from a Dene perspective and within the context of Treaty 8. Oral history and testimony from Dene Elders, knowledge-holders, leaders, and community members place Dénesųłıuné voices first. With supporting archival research, this book demonstrates how the founding, expansion, and management of Wood Buffalo National Park fits into a wider pattern of promises broken by settler colonial governments managing land use throughout the twentieth and twenty-first centuries. By prioritizing Dénesųłıuné histories Remembering Our Relations deliberately challenges how Dene experiences have been erased, and how this erasure has been used to justify violence against Dénesųłıuné homelands and people. Amplifying the voices and lives of the past, present, and future, Remembering Our Relations is a crucial step in the journey for healing and justice Dénesųłıuné peoples have been pursuing for over a century.
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► Cellulose can be effectively extracted from pine in AmimCl. The purity of the pine cellulose can reach as high as 85%. The reaction time is significantly reduced by microwave ...irradiation. IL dissolves pine by destroying inter and intramolecular hydrogen bonds. IL could be easily recycled and reused after extraction.
In the present study, 1-allyl-3-methylimidazolium chloride (AmimCl), an ionic liquid (IL), was used to extract cellulose from pine, poplar, Chinese parasol, and catalpa wood chips. Results show that pine is the most suitable wood species for cellulose extraction with ILs. Its cellulose extraction rate can reach as high as 62% under optimized conditions and its cellulose content is as high as 85% when DMSO/water is used as the precipitant. The dissolution process can be clearly observed by hot stage optical microscopy, and the reaction time can be significantly reduced by microwave irradiation. 13C CP/MAS NMR, FTIR, XRD, and SEM were used to analyze the cellulose-rich extracts of pine. Results show that IL dissolves pine wood by destroying inter and intramolecular hydrogen bonds between lignocelluloses. The major component of pine extract is cellulose with a homogeneous and dense structure. After extraction, AmimCl can be easily recycled and reused.
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