IMPACT4SOIL OpenAire UnpayWall Publikationenserver der Georg-August-Universität Göttingen Crossref Microsoft Academic Graph Europe PubMed Central Tree Physiology Open Access 2012-01-20 Effects of elevated CO2 concentration ([CO2]) on carbon (C) and nitrogen (N) uptake and N source partitioning (N2 fixation versus mineral soil N uptake) of 1-year-old Robinia pseudoacacia were determined in a dual 13C and 15N continuous labeling experiment. Seedlings were grown for 16 weeks in ambient (350 ppm) or elevated [CO2] (700 ppm) with 15NH4 15NO3 as the only mineral nitrogen source. Elevated [CO2] increased the fraction of new C in total C, but it did not alter C partitioning among plant compartments. Elevated [CO2] also increased the fraction of new N in total N and this was coupled with a shift in N source partitioning toward N2 fixation. Soil N uptake was unaffected by elevated [CO2], whereas N2 fixation was markedly increased by the elevated [CO2] treatment, mainly because of increased specific fixation (mg N mg(-1) nodule). As a result of increased N2 fixation, the C/N ratio of tree biomass tended to decrease in the elevated [CO2] treatment. Partitioning of N uptake among plant compartments was unaffected by elevated [CO2]. Total dry mass of root nodules doubled in response to elevated [CO2], but this effect was not significant because of the great variability of root nodule formation. Our results show that, in the N2-fixing R. pseudoacacia, increased C uptake in response to increased [CO2] is matched by increased N2 fixation, indicating that enhanced growth in elevated [CO2] might not be restricted by N limitations. 0106 biological sciences Seedlings Nitrogen Fixation Robinia 0401 agriculture, forestry, and fisheries 04 agricultural and veterinary sciences Carbon Dioxide 15. Life on land 01 natural sciences Trees Feng, Zhe, Dyckmans, Jens, Flessa, Heiner, 2004-03-01 journalpaper Effects of elevated CO2 concentration ([CO2]) on carbon (C) and nitrogen (N) uptake and N source partitioning (N2 fixation versus mineral soil N uptake) of 1-year-old Robinia pseudoacacia were determined in a dual 13C and 15N continuous labeling experiment. Seedlings were grown for 16 weeks in ambient (350 ppm) or elevated [CO2] (700 ppm) with 15NH4 15NO3 as the only mineral nitrogen source. Elevated [CO2] increased the fraction of new C in total C, but it did not alter C partitioning among plant compartments. Elevated [CO2] also increased the fraction of new N in total N and this was coupled with a shift in N source partitioning toward N2 fixation. Soil N uptake was unaffected by elevated [CO2], whereas N2 fixation was markedly increased by the elevated [CO2] treatment, mainly because of increased specific fixation (mg N mg(-1) nodule). As a result of increased N2 fixation, the C/N ratio of tree biomass tended to decrease in the elevated [CO2] treatment. Partitioning of N uptake among plant compartments was unaffected by elevated [CO2]. Total dry mass of root nodules doubled in response to elevated [CO2], but this effect was not significant because of the great variability of root nodule formation. Our results show that, in the N2-fixing R. pseudoacacia, increased C uptake in response to increased [CO2] is matched by increased N2 fixation, indicating that enhanced growth in elevated [CO2] might not be restricted by N limitations. Effects Of Elevated Carbon Dioxide Concentration On Growth And N-2 Fixation Of Young Robinia Pseudoacacia 10.1093/treephys/24.3.323 https://doi.org/10.1093/treephys/24.3.323