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Research article - Peer-reviewed, 2012

The below-ground perspective of forest plants: soil provides mainly organic nitrogen for plants and mycorrhizal fungi

Inselsbacher, Erich; Näsholm, Torgny

Abstract

Nitrogen (N) availability has a major impact on a wide range of biogeochemical processes in terrestrial ecosystems. Changes in N availability modify the capacity of plants to sequester carbon (C), but despite the crucial importance for our understanding of terrestrial ecosystems, the relative contribution of different N forms to plant N nutrition in the field is not known. Until now, reliably assessing the highly dynamic pool of plant-available N in soil microsites was virtually impossible, because of the lack of adequate sampling techniques. For the first time we have applied a novel microdialysis technique for disturbance-free monitoring of diffusive fluxes of inorganic and organic N in 15 contrasting boreal forest soils in situ. We found that amino acids accounted for 80% of the soil N supply, while ammonium and nitrate contributed only 10% each. In contrast to common soil extractions, microdialysis revealed that the majority of amino acids are available for plant and mycorrhizal uptake. Our results suggest that the N supply of boreal forest soils is dominated by organic N as a major component of plant-available N and thus as a regulator of growth and C sequestration.

Keywords

amino acids; diffusive flux; microdialysis; plant nutrition; soil nutrients

Published in

New Phytologist
2012, volume: 195, number: 2, pages: 329-334
Publisher: WILEY-BLACKWELL

Authors' information

Inselsbacher, Erich
Swedish University of Agricultural Sciences, Department of Forest Ecology and Management
Swedish University of Agricultural Sciences, Department of Forest Ecology and Management
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology

Sustainable Development Goals

SDG15 Life on land

UKÄ Subject classification

Forest Science

Publication Identifiers

DOI: https://doi.org/10.1111/j.1469-8137.2012.04169.x

URI (permanent link to this page)

https://res.slu.se/id/publ/40659