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This study aims to promote comprehensive utilization of woody biomass by providing a knowledgebase on the utility of aspen bark as a new alternative source for fossil-based chemicals. The research focused on the analysis of clonal variation in: (1) major chemical components, i.e., hemicelluloses, cellulose, and lignin; (2) extraneous materials, i.e., bark extractives, and suberic acid; (3) condensed tannins content and composition; and (4) screening differences in antioxidative properties and total phenolic content of hot water extracts and ethanol-water extracts of hybrid aspen bark. Results of this study, the discovery of clonal variation in utilizable chemicals, pave the way for further research on added-value potential of under-utilized hybrid aspen and its bark. Clonal variation was found in notable part of chemicals with potential for utilization. Based on the results, an appropriate bark raw material can be selected for tailored processing, thus improving the resource efficiency. The results also indicate that by applying cascade processing concepts, bark chemical substances could be more efficiently utilized with more environmentally friendly methods.

The magnitude and variation in DOC fluxes in bulk deposition (BD), stand throughfall (TF) and percolation water (PW) were determined on seven Scots pine and five Norway spruce plots in Finland during 1998–2004. Water fluxes for PW were calculated using an anion budget method. The relationships between the DOC fluxes and climatic and stand parameters were also investigated. The mean DOC flux in TF varied between 2 and 6 g C m–2 a–1 and between 3 and 8 g C m–2 a–1 on the pine and spruce plots, respectively. The output flux of DOC in PW at the 40-cm depth varied between 1 and 10 g C m–2 a–1 on all the plots. The DOC fluxes in TF and net TF correlated positively with the effective temperature sum and growing season length on the pine and spruce plots, i.e. the highest DOC fluxes were recorded in southern Finland and the fluxes decreased towards the north. The TF and net TF DOC fluxes correlated positively with the amount of precipitation on the pine plots, and the net TF DOC fluxes with the stem volume on the spruce plots.

Ash dieback (ADB) is threatening populations of European ash (Fraxinus excelsior & F. angustifolia) for more than three decades. Although much knowledge has been gathered in the recent past, practical conservation measures have been mostly implemented at local scale. Since range contraction in both ash species will be exacerbated in the near future by westward expansion of the emerald ash borer and climate change, systematic conservation frameworks need to be developed to avoid long-term population-genetic consequences and depletion of genomic diversity. In this article, we address the advantages and obstacles of conservation approaches aiming to conserve genetic diversity in-situ or ex-situ during tree pandemics. We are reviewing 47 studies which were published on ash dieback to unravel three important dimensions of ongoing conservation approaches or perceived conservation problems: i) conservation philosophy (i.e. natural selection, resistance breeding or genetic conservation), ii) the spatial scale (ecosystem, country, continent), and iii) the integration of genetic safety margins in conservation planning. Although nearly equal proportions of the reviewed studies mention breeding or active conservation as possible long-term solutions, only 17% consider that additional threats exist which may further reduce genetic diversity in both ash species. We also identify and discuss several knowledge gaps and limitations which may have limited the initiation of conservation projects at national and international level so far. Finally, we demonstrate that there is not much time left for filling these gaps, because European-wide forest health monitoring data indicates a significant decline of ash populations in the last 5 years.

The role of genotype in the durability of Scots pine (Pinus sylvestris L.) wood against decay by brown rot fungus (Coniophora puteana (Schum. ex Fr.) Karst. (strain Bam EBW 15)) was studied in a laboratory test. The wood material was obtained from 32-year-old half-sib progenies of Scots pine. The increment core samples of sapwood and juvenile heartwood were decayed using a modification of the standardized EN 113 method. The mean densities of the sapwood and heartwood samples were 391 and 337 mg(.)cm(-3), respectively, and the mean mass losses were 114 and 80 mg(.)cm(-3), respectively. The additive genetic components were small compared with the total phenotypic variance, which resulted in small narrow-sense heritabilities in mass loss. The most marked feature was the wide phenotypic variation in mass loss observed in heartwood (range 199 mg(.)cm(-3)) compared with sapwood (range 72 mg(.)cm(-3)) samples. Low heritability, together with the relatively high coefficient of additive genetic variation (CV(A)) in heartwood mass loss, suggests that advances in breeding can only be made through intensive testing in the environments which the studied experiment represents.