Structures et fonctions du bois des branches et du tronc chez l'Epicéa commun

Abstract : The structures of the branch provide several functions: support and mechanical resistance, hydraulic and protection. Here, we wanted to formalize and demonstrate the existence of relationships between functions and structures of the branches. Branches of two Norway spruce trees were analyzed, one tree positioned on the edge, another in the center of the same stand. Usually, the branch has smaller radial and longitudinal dimensions compared to the trunk. However, the branch is not a simple miniaturization of the trunk because it contains a high proportion of compression wood. Miniaturization is only effective in terms of size of ray and lumen without compression wood. Interverticillate axis A2 and axis A3 are less long-lived than the verticillate axis A2, so we wonder if the safety factor were lower. This was not the case; no difference in safety factor was observed between the three types of axis. Similarly, the protection function was expected to be stronger. This has not been demonstrated for verticillate and interverticillate A2: there have no differences between the two types of axis. Finally, the external forces should influence the hydraulic function. In fact, only the tree positioned in the center of the stand shows a difference in hydraulic structure between trunk and branch. On the contrary, no difference was observed among different branch types.
Document type :
Master thesis
File URL :
http://docnum.univ-lorraine.fr/prive/BUS_M_2013_GUO_ZIYU.pdf
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https://hal.univ-lorraine.fr/hal-01779403
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Submitted on : Thursday, April 26, 2018 - 3:36:16 PM
Last modification on : Friday, April 27, 2018 - 1:13:55 AM

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  • HAL Id : hal-01779403, version 1

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Ziyu Guo. Structures et fonctions du bois des branches et du tronc chez l'Epicéa commun. Sciences de l'environnement. 2013. ⟨hal-01779403⟩

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