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In situ 13 CO 2 pulse‐labelling of upland grassland demonstrates a rapid pathway of carbon flux from arbuscular mycorrhizal mycelia to the soil
Author(s) -
Johnson D.,
Leake J. R.,
Ostle N.,
Ineson P.,
Read D. J.
Publication year - 2002
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.0028-646x.2001.00316.x
Subject(s) - mycelium , botany , biology , labelling , agronomy , carbon fibers , grassland , flux (metallurgy) , chemistry , biochemistry , materials science , organic chemistry , composite number , composite material
Summary• The flux of pulse‐derived 13 C from upland pasture plants to the external mycelium of their arbuscular mycorrhizal (AM) symbionts was traced and quantified over a 7‐d post‐labelling period. • Mesh cores, which allowed in‐growth of native AM mycelium but were impenetrable to roots, were inserted into unlimed and limed plots and the surrounding vegetation was exposed to 13 CO 2 at ambient CO 2 concentrations. • Release of 13 CO 2 from cores colonized by AM mycelium peaked 9–14 h after labelling and declined within 24 h after severance of mycelial connections to roots. Between 5 and 8% of carbon lost by plants was respired by AM mycelium over the first 21 h after labelling. Liming increased the amount of carbon fixed by plants and subsequently allocated to fine roots and AM mycelium. • The results demonstrate for the first time under field conditions that AM mycelia provide a rapid and important pathway of carbon flux from plants to the soil and atmosphere.