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  • Author or Editor: Juan Guo x
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Abstract

Compression combined with steam (CS) treatment is postulated to be an environmentally friendly and efficient modification method to improve the dimensional stability, durability, and mechanical strength of wood. The influences of CS treatment with different radial compression ratios (RCRs) (25% and 50%) and different steam temperatures (140, 160 and 180°C) on chemical components, porosity, and hygroscopicity of earlywood and latewood in Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were investigated respectively on a cellular level by imaging Fourier Transform Infrared (FT-IR) microscopy, Confocal Raman Microscopy (CRM), nitrogen adsorption and dynamic vapor sorption (DVS). The results indicated that the degradation of carbonyl groups of the glucuronic acid component of xylan in earlywood and latewood was mainly responsible for the low hygroscopicity of CS-treated wood. Also, a significant decrease in the amount of C=O and C=C linked to the lignin aromatic skeleton involved in either crosslinking reactions or the degradation reactions could be another contributor to the reduction in wood hygroscopicity. CS-treated wood with a steam temperature of 180°C possessed a lower hygroscopicity that correlated well with the depolymerization of crystalline and amorphous cellulose. A more deformed structure of CS-treated wood led to the formation of greater amounts of mesopores in the cell walls, which could lead to increased degradation of the chemical components of wood cell walls. Furthermore, a higher equilibrium moisture content (EMC) level was found for CS-treated wood with a 50% compression ratio compared to a 25% compression ratio.

In: IAWA Journal

ABSTRACT

Pterocarpus santalinus, listed in CITES Appendix II, is an endangered timber species as a result of illegal harvesting due to its high value and commercial demand. The growing demand for P. santalinus and timbers with the morphologically similar Pterocarpus tinctorius has resulted in confusion as well as identification problems. Therefore, it is of vital importance to explore reliable ways to accurately discriminate between P. santalinus and P. tinctorius. In this study, the method of direct analysis in real time and fourier transform ion cyclotron resonance mass spectrometry (DART-FTICR-MS), combined with multivariate statistical analysis, was used to extract chemical information from xylarium wood specimens and to explore the feasibility of distinguishing these two species. Significant differences were observed in their DART-FTICR-MS spectra. Orthogonal partial least square-discriminant analysis (OPLS-DA) showed the highest prediction, with an accuracy of 100%. These findings demonstrate the feasibility of authenticating wood types using DART-FTICR-MS coupled with multivariate statistical analysis.

In: IAWA Journal

Abstract

DNA barcoding technology has emerged as one of the most promising tools available to identify timber at the species level, contributing to the monitoring of the timber trade and the conservation of forestry sources. This paper reviews the progress, challenges, and existing problems in the development of DNA barcoding for wood identification in the last ten years. There is a focus on the optimization of DNA extraction methods for processed or ancient wood, the strategy of screening high-resolution DNA barcodes suitable for wood identification, the development of a wood DNA reference database especially for priority taxa, and the comparison and comprehensive application of sequence analytical methods to achieve accurate identification. In addition to DNA barcoding, the feasibility of other genetic methods for wood identification is also discussed. Furthermore, future research orientation and strategy of wood DNA barcoding are presented. We argue that wood DNA barcoding integrated with other methodologies including wood anatomy can offer an effective approach and a new perspective to promote legal logging for timber trade custody and global biodiversity conservation.

In: IAWA Journal

ABSTRACT

The relationship between the cell wall ultrastructure of waterlogged wooden archeological artifacts and the state of water bound to cell walls and free in voids is fundamental to develop consolidating and drying technologies. Herein, a lacquer-wooden ware and a boat-coffin dating 4th century BC were selected as representative artifacts to study. Wood anatomy results indicated that they belonged to Idesia sp. and Machilus sp., respectively. They exhibited a typical spongy texture, as revealed by SEM observations, and their water contents had increased significantly. Solid state NMR, Py-GC/MS, imaging FTIR microscopy and 2D-XRD results demonstrated that the deterioration resulted from the partial cleavages of both polysaccharide backbones and cellulose hydrogen-bonding networks, almost complete elimination of acetyl side chains of hemicellulose, the partial depletion of β-O-4 interlinks, as well as oxidation and demethylation/demethoxylation of lignin. These further caused the disoriented arrangement of crystalline cellulose, and the decrease in cellulose crystallite dimensions and crystallinity. In consequence, mesopores and macropores formed, and the number of moisture-adsorbed sites and their accessibility increased. Moreover, results on free water deduced by the changes of pore structure and the maximum monolayer water capacity achieved by the GAB model indicated that water in waterlogged archeological wooden artifacts was mainly free water in mesopores.

In: IAWA Journal

Abstract

Oaks are important tree species, providing essential biomaterial for the wood industry. We characterize and compare wood anatomical traits of plantation grown Quercus acutissima Carruth. and Q. variabilis Blume to provide more detailed information to understand xylem radial growth, structure, and function, as well as differences between sapwood and heartwood, to provide data relevant for tree breeding and value-added wood utilization of oak plantations in China. In this study, radial strips were collected at breast height from the main trunk of the two species. Latewood percentage and growth ring width were investigated by X-ray densitometry and a Tree Ring Analysis System, respectively. Vessel and fibre lumen diameter, vessel and fibre wall thickness, vessel density, fibre wall thickness/diameter ratio, tissue proportions, and pit membrane thickness in between vasicentric tracheids were observed with light microscopy and electron microscopy and quantified. There were significant differences in a few wood anatomical traits between the two species: vessel wall thickness and vessel lumen diameter were higher in Q. acutissima than in Q. variabilis, while higher axial parenchyma proportion in sapwood was found in Q. variabilis than in Q. acutissima. More abundant tyloses were found in heartwood than in sapwood of both species. Our work showed the intraspecific and interspecific variation of the two species. Most differences between sapwood and heartwood must be attributed to differences in cambial age during their formation.

In: IAWA Journal

With 60% of all primate species now threatened with extinction and many species only persisting in small populations in forest fragments, conservation action is urgently needed. But what type of action? Here we argue that restoration of primate habitat will be an essential component of strategies aimed at conserving primates and preventing the extinctions that may occur before the end of the century and propose that primates can act as flagship species for restoration efforts. To do this we gathered a team of academics from around the world with experience in restoration so that we could provide examples of why primate restoration ecology is needed, outline how primates can act as flagship species for restoration efforts of tropical forest, review what little is known about how primate populations respond to restoration efforts, and make specific recommendations of the next steps needed to make restoration of primate populations successful. We set four priorities: (1) academics must effectively communicate both the value of primates and the need for restoration; (2) more research is needed on how primates contribute to forest restoration; (3) more effort must be put into Masters and PhD level training for tropical country nationals; and finally (4) more emphasis is needed to monitor the responses of regenerating forest and primate populations where restoration efforts are initiated. We are optimistic that populations of many threatened species can recover, and extinctions can be prevented, but only if concerted large-scale efforts are made soon and if these efforts include primate habitat restoration.

In: Folia Primatologica

Abstract

Historically, Internet access has been linked to a country’s wealth. However, starting a decade ago, this situation changed dramatically and Internet access became increasingly available in primate range countries. The rapid growth of smartphone use in developing nations has created new avenues to communicate conservation. Here we assess the potential of social media to promote primate conservation at the local level within primate range countries. We interviewed 381 people in communities associated with 18 conservation projects from 11 countries to assess their use of social media. We found that 91% of the people had at least one social media account and 95% of these people checked their accounts daily. The median number of contacts per person across all platforms was 453 and 300 considering only each person’s most used platform. We also documented that local conservation projects had a diversity of information they wanted to relay to the local community through social media. Our research highlights the potential for social media to be an extremely useful communication tool for tropical conservation scientists. Thus, we encourage more conservation groups to explore using social media to communicate to local communities and to report on the impact it has on conservation.

In: Folia Primatologica