Articles containing the keyword 'biomechanics'

It is commonly accepted that the period of early-spring xylem sap exudation marks a stage during which a positive pressure builds inside the tree trunks. This state changes when leaves appear, initiating water transport within the trunk. It is unknown, however, how the wood anatomical structure and its mechanical resistance influences the sap. We present the results of research on the relationship between exudation of sap from Betula pendula Roth trees from the interior of a forest stand and from its edge, and the anatomical structure of the trunk wood and its bending strength. During the period between March 21 and April 18, we performed five sets of measurements of sap exudation from trees at the edge of the stand and from the forest interior. The resulting radial wood samples were tested for bending strength using a fractometer. We tested the sap for electrolytic conductivity and sugars content. For the anatomical analysis of the wood, we determined the number of vessels per 1 mm², average vessel lumen area and potential conductivity index. We found that the trees along the edge of the stand exude more sap, but it is less concentrated than the sap from the trees from the interior. Bending strength perpendicular to wood fibres is higher in the trees from the stand edge and in the western side of the trunk, where the number of vessels per 1 mm² and conductivity index are smaller. Seemingly, this is the result of western winds, which are dominant in Poland.

• Zajączkowska, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: urszula.zajaczkowska@wl.sggw.pl
• Kaczmarczyk, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: karina.kaczmarczyk@wl.sggw.pl
• Liana, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: janusz.liana@wl.sggw.pl

• Qi, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France; Institute of Automation, Chinese Academy of Sciences, LIAMA/NLPR, P.O.Box 2728, Beijing, China E-mail: qiruitree@gmail.com
• Letort, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France E-mail: vl@nn.fr
• Kang, Institute of Automation, Chinese Academy of Sciences, LIAMA/NLPR, P.O.Box 2728, Beijing, China E-mail: mk@nn.cn
• Cournède, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France; INRIA saclay Ile-de-France, EPI Digiplant, Parc Orsay Université, 91893 Orsay cedex, France E-mail: phc@nn.fr
• Reffye, INRIA saclay Ile-de-France, EPI Digiplant, Parc Orsay Université, 91893 Orsay cedex, France; CIRAD, UMR AMAP, Montpellier, F-34000 France E-mail: pdr@nn.fr
• Fourcaud, CIRAD, UMR AMAP, Montpellier, F-34000 France E-mail: tf@nn.fr