Density profile and microstructural analysis of densified beech wood (Fagus sylvatica L.) plasticized by microwave treatment

Author

• Jakub DöményEmail author
• Petr Čermák
• Vojtěch Koiš
• Jan Tippner
• Radim Rousek

DOI: 10.1007/s00107-017-1173-z

Cite this article as: 

Dömény, J., Čermák, P., Koiš, V. et al. Eur. J. Wood Prod. (2017). doi:10.1007/s00107-017-1173-z

Abstract

This study was carried out in order to determine the efficacy of microwave (MW) plasticization for wood densification purposes. The plasticization process was carried out using a continuous feed laboratory MW at a frequency of 2.45 GHz. European beech (Fagus sylvatica L.) specimens measuring 50 mm × 40 mm × 8 mm were MW treated (plasticized) with an output of 3.5 kW at a conveyor speed of 0.4 m/min. Afterwards, MW plasticized specimens were densified with a ratio of 50%. Microscopic structure changes of densified wood were detected using a scanning electron microscope (SEM) and density profiles were measured using the X-ray densitography. An average density of 677 kg m−3 and 771 kg m−3increased significantly to 951 kg m−3 for radially densified and to 1194 kg m−3 for tangentially densified specimens. X-ray densitography results show uniformity of density profiles through specimen thickness, which confirmed the evenly plasticized volume of wood. Microscopic structure observation revealed that the MW plasticization was not accompanied by any fractures, and deformations present in the densified wood were due to viscoelastic buckling of cell walls without crack propagation. Therefore, MW treatment can be considered as an effective method for wood plasticization.

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Assessment of ecosystem services at the national level in Germany—Illustration of the concept and the development of indicators by way of the example wood provision

Published Date
Ecological Indicators
November 2016, Vol.70:181–195, doi:10.1016/j.ecolind.2016.06.010

Navigating Urban Complexity: Advancing Understanding of Urban Social – Ecological Systems for Transformation and Resilience

• Author 

• Karsten Grunewald ^a,,
• Hendrik Herold ^a,
• Stefan Marzelli ^b,
• Gotthard Meinel ^a,
• Benjamin Richter ^a,
• Ralf-Uwe Syrbe ^a,
• Ulrich Walz ^c,

• aLeibniz Institute of Ecological Urban and Regional Development, Weberplatz 1, 01217 Dresden, Germany
• bIfuplan – Institut für Umweltplanung und Raumentwicklung, Amalienstr. 79, 80799 München, Germany
• cHochschule für Technik und Wirtschaft Dresden (HTW), Friedrich-List-Platz 1, 01069 Dresden, Germany

Received 4 February 2016. Revised 30 May 2016. Accepted 7 June 2016. Available online 22 June 2016. 

Highlights

• •
  Explanation of the “German framework” following MAES and CICES recommendations.
• •
  Priorisation of 21 ecosystem services classes to be handled.
• •
  Principles of the description of indicandum and indicator (template).
• •
  Illustration of the procedure by the example raw wood production.
• •
  Discussion of the indicator in relationship to sustainability and biodiversity.

Abstract

The EU Biodiversity Strategy stipulates in Target 2, Action 5 that the member states must map and assess the state of the ecosystems and their services and promote the integration into the reporting systems at the EU and national level by 2020. Therefore indicators for capturing and assessing ecosystem services (ES) are needed. In this paper we report for which ES class types currently ES indicators are being developed for Germany in the context of an ongoing research project. Additionally, we provide the indicator specifications, which are based on underlying framework concept. By way of the example of the provisioning service ‘raw wood production’ and the development of the main-indicator ‘annual wood accrual’ and six sub-indicators, we illustrate the concrete procedure, including discussion of results and target values. The indicators for the ES wood provision are not only suitable for an exemplary illustration of procedure, data selection and data basis in Germany. Furthermore, it shows that indicators for provisioning ES can eminently conflict with biodiversity and other ES.

Keywords

Biodiversity

CICES classification

Ecosystem services

Forest management

Raw wood production

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• ⁎ 
  Corresponding author.

© 2016 Elsevier Ltd. All rights reserved.

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http://www.sciencedirect.com/science/article/pii/S1470160X16303090

Underground riparian wood: Buried stem and coarse root structures of Black Poplar (Populus nigraL.)

Published Date
Geomorphology
15 February 2017, Vol.279:188–198, doi:10.1016/j.geomorph.2016.08.002
Dynamics and ecology of Wood in World Rivers

• Author 

• James V. Holloway ^a,,
• Matthias C. Rillig ^b,c
• Angela M. Gurnell ^a

• aQueen Mary University of London, School of Geography, Mile End Road, London, E1 4NS, United Kingdom
• bFreie Universität Berlin, Institut für Biologie, Plant Ecology, Altensteinstr. 6, Berlin D-14195, Germany
• cBerlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin D-14195, Germany

Received 23 December 2015. Revised 31 July 2016. Accepted 2 August 2016. Available online 4 August 2016. 

Highlights

• •
  The underground biomass of Black Poplar is deep and morphologically complex.
• •
  Roots extend to below the bar surface where the original tree established.
• •
  The main buried axis is typically a stem from which new shoots and roots emanate.
• •
  Steps and bends in the main axis reflect the surrounding sediment structure.
• •
  This underground wood possesses traits that may tighten fluvial wood budgets.

Abstract

Despite the potential importance of tree species in influencing the processes of wood recruitment, transport, retention, and decay that control river wood budgets, focus has been relatively limited on this theme within fluvial wood research. Furthermore, one of the least investigated topics is the belowground living wood component of riparian trees.

This paper presents observations of the morphology and age of buried stem and coarse root structures of eight Populus nigra individuals located in the riparian woodland of two sites on the middle to lower Tagliamento River, Italy. This species was selected because of its wide distribution along European rivers and its frequent dominance of riparian woodland.

Each tree was excavated by hand to expose a minimum of half of the root system with complete exposure of the main axis. Smaller roots were then removed and larger protruding roots cut back to permit access to the main axis. The excavated structures were photographed from multiple angles for photogrammetric modelling; the structure and character of the exposed sediments around the tree's main axis were recorded; and wood samples were taken from the main aboveground stem(s), sections of the main buried axis, and major roots for dendrochronological analysis. Results from these field observations and laboratory dating of the wood samples were combined to describe the belowground morphology of each tree and to draw inferences concerning the impact of fluvial disturbances.

Common features of these excavated structures included: (i) rooting depths to below the bar surface where the original tree established, with many young roots also existing at depth; (ii) translocation of the main buried axis in a downstream direction; (iii) a main buried axis comprised mainly of stems that have become buried and then generated new shoots, including multistem patches, and adventitious roots; (iv) the presence of steps and bends in the main buried axis associated with the generation of coarse lateral roots, that reflect the sedimentary structure of the surrounding aggraded bank sediments; and (v) grafting of roots within and between some sampled trees.

Overall, the sampled trees possessed extremely complex three-dimensional buried wood structures that permeate bank sediments and tie the tree and aggraded bank sediments to basal gravels. These properties and the considerable amount of underground wood that is present have great significance for anchoring trees and giving uprooted trees and root wads a propensity to snag once they enter the fluvial system. Furthermore, the ability of this underground biomass to sprout suggests that uprooted and remaining components of root networks following tree uprooting may resprout, generating new vegetation canopies that can trap mobile wood. Overall, this underground wood offers many traits that may tighten wood budgets, and it is likely that other riparian Salicaceae species with similar traits may have similar wood budget impacts.

Keywords

Populus nigra

Underground wood

Buried stems

Adventitious roots

Root system architecture

Structure-from-motion

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• ⁎ 
  Corresponding author.

© 2016 Elsevier B.V. All rights reserved.

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