Record ID No. |
3825 |
Author(s) |
Inselsbacher E, Näsholm T. , 2012 |
Affiliation |
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden. erich.inselsbacher@slu.se |
Title |
The below-ground perspective of forest plants: Soil provides mainly organic nitrogen for plants and mycorrhizal fungi |
Source. Vol.(no):Page |
New Phytol. 195(2):329-34p. |
Categories |
Mycorrhiza General |
Subjects |
Biochemistry |
Sub-subjects |
Nitrogen metabolism |
Host |
Plants |
Organism |
Mycorrhiza |
Country |
Sweden, Europe |
Abstracts |
• 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.
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