Summer drought alters carbon allocation to roots and root respiration in mountain grassland. Issue 3 (10th November 2014)

• Record Type: Journal Article
• Authors: Hasibeder, Roland; Fuchslueger, Lucia; Richter, Andreas; Bahn, Michael
• Is Part Of: New phytologist. Volume 205:Issue 3(2015)
• Page Start: 1117
• Page End: 1127
• Publication Date: 2014-11-10
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13146
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13146-abs-0001"> <title>Summary</title> <p> <list id="nph13146-list-0001" list-type="bullet"> <list-item> <p>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.</p> </list-item> <list-item> <p>We combined experimental rain exclusion with ¹³C 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.</p> </list-item> <list-item> <p>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.</p> </list-item> <list-item> <p>Our results indicate that under drought conditions the usage of recent photosynthates is shifted from metabolic activity to osmotic adjustment and storage compounds.</p> </list-item> </list> </p> </abstract>