Work

Carbon–nitrogen relations of ectomycorrhizal mycelium across a natural nitrogen supply gradient in boreal forest

Year: 2021

Type: article

Abstract: Summary The supply of carbon (C) from tree photosynthesis to ectomycorrhizal (ECM) fungi is known to decrease with increasing plant nitrogen (N) supply, but how this affects fungal nutrition and growth remains to be clarified. We placed mesh‐bags with quartz sand, with or without an organic N (15N‐, 13C‐labeled) source, in the soil along a natural N supply gradient in boreal forest, to measure growth and use of N and C by ECM extramatrical mycelia. Mycelial C : N declined with increasing N supply. Addition of N increased mycelial growth at the low‐N end of the gradient. We found an inverse relationship between uptake of added N and C; the use of added N was high when ambient N was low, whereas use of added C was high when C from photosynthesis was low. We propose that growth of ECM fungi is N‐limited when soil N is scarce and tree belowground C allocation to ECM fungi is high, but is C‐limited when N supply is high and tree belowground C allocation is low. This suggests that ECM fungi have a major role in soil N retention in nutrient‐poor, but less so in nutrient‐rich boreal forests.

Source: New Phytologist

DOI: 10.1111/nph.17701

Authors: Mona N. Högberg, Peter Högberg, Håkan Wallander, Lars‐Ola Nilsson

Institutions: Swedish University of Agricultural Sciences, Lund University, University of Copenhagen, Halmstad University

Language: English

Topic: Mycorrhizal Fungi and Plant Interactions

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Life on land

Open Access status: hybrid

Estimated APC paid: $3,000