Dynamics of initial carbon allocation after drought release in mature Norway spruce-Increased belowground allocation of current photoassimilates covers only half of the carbon used for fine-root growth
Abstract
After drought events, tree recovery depends on sufficient carbon (C) allocation to the sink organs. The present study aimed to elucidate dynamics of tree-level C sink activity and allocation of recent photoassimilates (Cnew ) and stored C in c. 70-year-old Norway spruce (Picea abies) trees during a 4-week period after drought release. We conducted a continuous, whole-tree 13 C labeling in parallel with controlled watering after 5 years of experimental summer drought. The fate of Cnew to growth and CO2 efflux was tracked along branches, stems, coarse- and fine roots, ectomycorrhizae and root exudates to soil CO2 efflux after drought release. Compared with control trees, drought recovering trees showed an overall 6% lower C sink activity and 19% less allocation of Cnew to aboveground sinks, indicating a low priority for aboveground sinks during recovery. In contrast, fine-root growth in recovering trees was seven times greater than that of controls. However, only half of the C used for new fine-root growth was comprised of Cnew while the other half was supplied by stored C. For drought recovery of mature spruce trees, in addition to Cnew , stored C appears to be critical for the regeneration of the fine-root system and the associated water uptake capacity.
Bibliografische Daten
Originalsprache | Englisch |
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ISSN | 1354-1013 |
DOIs | |
Status | Veröffentlicht - 12.2022 |
Extern publiziert | Ja |
Anmerkungen des Dekanats
© 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
PubMed | 36039835 |
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