Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: Changes in carbon uptake and allocation patterns in Quercus robur seedlings in response to elevated an 2 CO and water stress: C 13 labelling. | Ann Sci For 1997 54 597-610 Elsevier Inra 597 Original article Changes in carbon uptake and allocation patterns in Quercus robur seedlings in response to elevated CO2 and water stress an evaluation with 13c labelling p Vivin JM Guehl Equipe bioclimatologie et écophysiologie forestieres Inra Nancy 54280 Champemmx France Received 11 April 1997 accepted 2 July 1997 Summary - A semi-closed l3CO2 labelling system l3C was used to assess both carbon uptake and allocation within pedunculate oak seedlings Quercus robur L grown under ambient 350 vpm and elevated 700 vpm atmospheric CO2 concentration CO2 and in either well-watered or draughted conditions. Pulse-chase l3C labelling data highlighted the direct positive effect of elevated co2 on photosynthetic carbon acquisition. Consequently in well-watered conditions CO2-enriched plants produced times more biomass dry mass at harvest and times more dry root matter coarse plus fine roots over the 22-week growing period than plants grown under ambient CO2 . The root shoot biomass ratio was decreased both by drought and CO2 despite lower N concentrations in CO2-enriched plants. However both long-term and short-term c allocation to fine roots were not altered by CO2 and relative specific allocation RSA a parameter expressing sink strength was higher in all plant organs under 700 vpm compared to 350 vpm. Results showed that c availability for growth and metabolic processes was greater in fine roots of oaks grown under an elevated CO2 atmosphere irrespective of soil water availability. elevated CO2 drought growth 3C labelling carbon assimilation carbon allocation Resume - Effets de 1 augmentation de la concentration atmosphérique en CO2 et de la séche-resse sur 1 assimilation et la redistribution du carbone de plants de Quercus robur une approche par marquage 13c. Un sySterne semi-ferme de marquage isotopique par l3CO2 1 5 l 3C a été utilise pour évaluer 1 assimilation et la repartition du carbone pour des plants de .
