Annual shoot-growth in Nothofagus antarctica (G. Forster) Oersted (Nothofagaceae) from northern Patagonia

• Published in: Trees
• Main Authors: Stecconi, M., Marina, Puntieri, Javier G., Barthélémy, Daniel
• Other Authors: Universidad Nacional del Comahue Neuquén (UNCOMA), BotAnique et BioinforMatique de l'Architecture des Plantes (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Recherche pour le Développement (IRD France-Ouest )-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2000
• Subjects: Extension period; Extension rate; Nothofagus; Plant architecture; Shoot growth; [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics; Phylogenetics and taxonomy; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Patagonia; Antarc*; Antarctica
• Online Access: https://hal.inrae.fr/hal-03769607; https://doi.org/10.1007/PL00009770

International audience The growth dynamics of annual shoots of Nothofagus antarctica shrubs from northern Patagonia was studied. The pattern of extension of the shoots derived from the three most distal buds of 100 parent shoots was registered. Weekly measurements and observations of extending shoots were carried out during the 1996–1997 growth season. The date of shoot extension initiation was less variable than the date of shoot extension cessation. Extension curves had an asymmetrically sigmoid outline. Most extension took place uninterruptedly between mid-September 1996 and the end of January 1997. Extension rate reached its highest value in the second half of the extension period. Leaf unfolding rate had a peak early in the extension period and fluctuated irregularly later on. The apical meristem of all shoots died by the end of shoot extension. In general terms, shoot length, diameter, leaf number and extension duration decreased from the first to the third position from the parent shoot’s apex, although exceptions to this pattern were found. Shoot extension rate was affected by maximum and minimum daily temperatures but not by the amount of precipitation during the extension period. The size of a bud was not related to the size of the shoot derived from it. The size of shoots in the third position from the apex was related to parent shoot size; this was not the case for more distal shoots.