Research article - Peer-reviewed, 2021
Tree water uptake enhances nitrogen acquisition in a fertilized boreal forest - but not under nitrogen-poor conditionsHenriksson, Nils; Lim, Hyungwoo; Marshall, John; Franklin, Oskar; McMurtrie, Ross E.; Lutter, Reimo; Magh, Ruth; Lundmark, Tomas; Nasholm, Torgny
AbstractUnderstanding how plant water uptake interacts with acquisition of soil nitrogen (N) and other nutrients is fundamental for predicting plant responses to a changing environment, but it is an area where models disagree. We present a novel isotopic labelling approach which reveals spatial patterns of water and N uptake, and their interaction, by trees. The stable isotopes N-15 and H-2 were applied to a small area of the forest floor in stands with high and low soil N availability. Uptake by surrounding trees was measured. The sensitivity of N acquisition to water uptake was quantified by statistical modelling. Trees in the high-N stand acquired twice as much N-15 as in the low-N stand and around half of their N uptake was dependent on water uptake (H-2 enrichment). By contrast, in the low-N stand there was no positive effect of water uptake on N uptake. We conclude that tree N acquisition was only marginally dependent on water flux toward the root surface under low-N conditions whereas under high-N conditions, the water-associated N uptake was substantial. The results suggest a fundamental shift in N acquisition strategy under high-N conditions.
KeywordsN-15; deuterium; diffusion; isotope; mass flow; nitrogen uptake; Pinus sylvestris (Scots pine); water uptake
Published inNew Phytologist
2021, volume: 232, number: 1, pages: 113-122
The Czech Academy of Sciences
Marshall, John D (Marshall, John)
International Institute for Applied Systems Analysis (IIASA)
McMurtrie, Ross E.
University of New South Wales Sydney
Estonian University of Life Sciences
UKÄ Subject classification
URI (permanent link to this page)