Soil diffusive fluxes constitute the bottleneck to tree nitrogen nutrition in a Scots pine forest

Autor(en)

Olusegun Ayodeji Oyewole, Sandra Jamtgard, Linda Gruffman, Erich Inselsbacher, Torgny Näsholm

Abstrakt

In nutrient poor environments, plant nitrogen (N) acquisition is governed by soil diffusive fluxes and root uptake capacities. However, the relationship between these two processes is not well understood. We explored a way of comparing the processes, enabling identification of the limiting factor for tree N acquisition.

The study comprised N-fertilized and N-limited Scots pine stands, and measurements of uptake capacities of detached tree roots and of induced soil diffusive fluxes (through in-situ microdialysis) done at the onset and the end of the growing season.

Soil N fluxes were higher at the onset than at the end of the growing season and amino acids comprised a larger fraction of N than inorganic N. N fertilization reduced root uptake capacities of NH4 (+), glycine and NO3 (-) but not of arginine. For all N compounds except NO3 (-), diffusive fluxes were significantly lower than root N uptake capacities.

Our results suggest that soil N supply in both, N-fertilized and N-limited forest stands, is dominated by amino acids, thus being the major component of plant-available N. Uptake of N appears more constrained by the diffusive fluxes of N compounds rather than root uptake capacity, except for NO3 (-).

Organisation(en)

Institut für Geographie und Regionalforschung

Externe Organisation(en)

Swedish University of Agricultural Sciences (SLU)

Journal

Plant and Soil: international journal on plant-soil relationships

Band

399

Seiten

109-120

Anzahl der Seiten

12

ISSN

0032-079X

DOI

https://doi.org/10.1007/s11104-015-2680-5

Publikationsdatum

2016

Peer-reviewed

Ja

ÖFOS 2012

106030 Pflanzenökologie, 105405 Geoökologie

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/soil-diffusive-fluxes-constitute-the-bottleneck-to-tree-nitrogen-nutrition-in-a-scots-pine-forest(2aa3828e-25ae-4e7d-8536-81502895f783).html