Publication
Title
Summer drought alters carbon allocation to roots and root respiration in mountain grassland
Author
Abstract
Drought affects the carbon (C) source and sink activities of plant organs, with potential consequences for belowground C allocation, a key process of the terrestrial C cycle. The responses of belowground C allocation dynamics to drought are so far poorly understood. We combined experimental rain exclusion with C-13 pulse labelling in a mountain meadow to analyse the effects of summer drought on the dynamics of belowground allocation of recently assimilated C and how it is partitioned among different carbohydrate pools and root respiration. Severe soil moisture deficit decreased the ecosystem C uptake and the amounts and velocity of C allocated from shoots to roots. However, the proportion of recently assimilated C translocated belowground remained unaffected by drought. Reduced root respiration, reflecting reduced C demand under drought, was increasingly sustained by C reserves, whilst recent assimilates were preferentially allocated to root storage and an enlarged pool of osmotically active compounds. Our results indicate that under drought conditions the usage of recent photosynthates is shifted from metabolic activity to osmotic adjustment and storage compounds.
Language
English
Source (journal)
New phytologist. - Oxford
Publication
Oxford : 2015
ISSN
0028-646X
Volume/pages
205 :3 (2015) , p. 1117-1127
ISI
000348730600024
Full text (Publisher's DOI)
UAntwerpen
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 18.10.2018
Last edited 28.08.2021