UV light impact on ellagitannins and wood surface colour of European oak (Quercus petraea and Quercus robur)

2007 ◽  
Vol 253 (11) ◽  
pp. 4985-4989 ◽  
Author(s):  
S. Zahri ◽  
C. Belloncle ◽  
F. Charrier ◽  
P. Pardon ◽  
S. Quideau ◽  
...  
Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 1032-1045
Author(s):  
MONIKA SARVAŠOVÁ KVIETKOVÁ ◽  
MIROSLAV GAŠPARÍK

This paper deals with the effect of saw blade type (24, 40 and 60 teeth) and sawn distance on the primary profile (Pz) of tranvesre surface of European oak (Quercus robur L.) after transversal cutting. Transversal cutting was provided at constant cutting speed vc = 62 m.s-1and with manual feeding using circular saw blade. An additional parameter was to determine the maximum sawn distance for each type of saw blade up to the point where the saw blade overheated, as well as the beginning of the blackening of the wood surface. The highest values of the primary profile (Pz) were achieved with a saw blade with 24 teeth, lower values were measured on wood cut with a 40 tooth blade and the lowest values after cutting with a 60 tooth blade. As the saw distance increased, there was no rapid and steep increase in the primary profile values, but these values gradually increased slightly, probably due to the gradual blunting of the tool.


PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0134935 ◽  
Author(s):  
Peter Annighöfer ◽  
Philip Beckschäfer ◽  
Torsten Vor ◽  
Christian Ammer

2007 ◽  
pp. 55-67 ◽  
Author(s):  
Slobodan Milanovic

The development of Gypsy moth (Lymantria dispar L) was monitored in laboratory conditions, on the foliage of the species Quercus cerris L. Quercus petraea (Matt) Liebl. and Quercus robur L. The experiment was established in the controlled environmental conditions, at the temperature of 25?C, photoperiod 14:10 (day: night) and relative humidity 70%. The objective of the research was to determine the suitability of the study host plant species for gypsy moth development. The study results show that Gypsy moth caterpillars cultivated on Q. petraea foliage had a lower survival, higher number of moultings, longer preadult development and lower fecundity, which makes this species less suitable compared to the other two. Gypsy moth caterpillars cultivated on Q. cerris foliage had the highest survival degree the lowest number of moultings, the shortest preadult development and the highest fecundity, which makes this species the most favourable for gypsy moth development. Q. robur was between the former two species in this respect.


Metabolites ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 684
Author(s):  
Gaëlle Buche ◽  
Cyril Colas ◽  
Laëtitia Fougère ◽  
Emilie Destandau

Two species of oak are dominant in French forests: pedunculate oak (Quercus robur L.) and sessile oak (Quercus petraea Liebl.). Their differentiation is not straightforward but is essential to better understand their respective molecular content in order to better valorize them. Thus, to improve oak species identification, an untargeted UHPLC-HRMS/MS method associated with a two-step data treatment was developed to analyze a wide range of specialized metabolites enabling the comparison of both species of oak extracts. Pooled extracts from sessile and pedunculate oaks, composed of extracts from several trees of pure species from various origins, were compared using first the Venn diagram, as a quick way to get an initial idea of how close the extracts are, and then using a molecular network to visualize, on the one hand, the ions shared between the two species and, on the other hand, the compounds specific to one species. The molecular network showed that the two species shared common clusters mainly representative of tannins derivatives and that each species has specific molecules with similar fragmentation patterns, associated in specific clusters. This methodology was then applied to compare these two pooled extracts to unknown individuals in order to determine the species. The Venn diagram allowed for the quick presumption of the species of the individual and then the species could be assigned more precisely with the molecular network, at the level of specific clusters. This method, developed for the first time, has several interests. First, it makes it possible to discriminate the species and to correctly assign the species of unknown samples. Moreover, it gave an overview of the metabolite composition of each sample to better target oak tree utilization and valorization.


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