Evidence for Transient increase of rhizodeposition  following a severe defoliation of Plantago arenaria

TY - JOUR

T1 - Evidence for Transient increase of rhizodeposition  following a severe defoliation of Plantago arenaria

AU - Henry, Frédéric

AU - Madsen, Mette Vestergård

AU - Christensen, Søren

N1 - Keywords: Rhizodeposition; Defoliation; Carbon; Plantago arenaria; Microcosms

PY - 2007

Y1 - 2007

N2 - Plants are often grazed resulting in a sudden and significant removal of shoot tissue, which decreases photosynthesis and changes Callocation between within the plant. From results obtained in percolated sand it is possible to demonstrate an increase of rhizodepositionwithin few days after defoliation followed by a decrease of rhizodeposition. The aim of our study was to test if this pattern can be alsoobserved for plants grown in soil. We grew Plantago arenaria in microcosms and defoliated half of them after 45 d. Half of the defoliatedand non-defoliated microcosms were harvested 1.5 d, and the other half 8.5 d, after defoliation. We observed an increase of microbialbiomass 1.5 d after defoliation followed by a decrease assessed 8.5 d after the treatment. In parallel, soil soluble C and the metabolicquotient of the microbial biomass first decreased and then increased at the second harvest reaching values equivalent to those of the nondefoliatedtreatment. Based on these results together with results obtained in artificial soil, we conclude that the defoliation of P. arenariagrown in soil leads to a transient peak of root exudation.

AB - Plants are often grazed resulting in a sudden and significant removal of shoot tissue, which decreases photosynthesis and changes Callocation between within the plant. From results obtained in percolated sand it is possible to demonstrate an increase of rhizodepositionwithin few days after defoliation followed by a decrease of rhizodeposition. The aim of our study was to test if this pattern can be alsoobserved for plants grown in soil. We grew Plantago arenaria in microcosms and defoliated half of them after 45 d. Half of the defoliatedand non-defoliated microcosms were harvested 1.5 d, and the other half 8.5 d, after defoliation. We observed an increase of microbialbiomass 1.5 d after defoliation followed by a decrease assessed 8.5 d after the treatment. In parallel, soil soluble C and the metabolicquotient of the microbial biomass first decreased and then increased at the second harvest reaching values equivalent to those of the nondefoliatedtreatment. Based on these results together with results obtained in artificial soil, we conclude that the defoliation of P. arenariagrown in soil leads to a transient peak of root exudation.

KW - Faculty of Science

KW - Rhizodeposition

KW - Defoliation

KW - Carbon

KW - Plantago arenaria

KW - Microcosms

U2 - 10.1016/j.soilbio.2007.12.015

DO - 10.1016/j.soilbio.2007.12.015

M3 - Journal article

SN - 0038-0717

JO - Soil Biology & Biochemistry

JF - Soil Biology & Biochemistry

ER -