Elevated pCO2 affects N-metabolism of young poplar plants (Populus tremula × P. alba) differently at deficient and sufficient N-supply.

摘要: Summary • The effects of N-availability and elevated atmospheric CO 2 partial pressure ( pCO2) on growth, allometry N-metabolism poplar plants are reported here. • Poplar were grown hydroponically at deficient sufficient N-supply under ambient pCO2. The N-fluxes within the estimated by comparing fate newly acquired 15N-NO3− in either severely N-limited or with N-supply. • At N-supply, accumulated less biomass exhibited an increased root : shoot ratio compared N-supply; a larger fraction 15 N was allocated to youngest leaves immediately after exchange nutrient solution. Increasing external from shifted site nitrate reduction roots leaves. • Elevated pCO2 total but had no effect N-supply. Elevated decreased rates N-uptake both treatments. Increased coincided enhanced root also allocation 15N leaves. Root as possible factor controlling N-allocation is discussed.