Post-drought recovery of carbon transport and allocation in mature Norway spruce after five years of repeated summer drought
AGU (Hrsg). AGU Fall Meeting 2021. 2021
Erscheinungsjahr: 2021
Publikationstyp: Diverses (Konferenzbeitrag)
Sprache: Englisch
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Inhaltszusammenfassung
The ability of trees to recover functionality during post drought events is an important factor for tree survival and productivity. To elucidate the resilience of carbon (C) transport and the role of C allocation during post-drought recovery, we performed a whole-tree 13C labeling experiment on c. 70-year-old Norway spruce (Picea abies [L.] Karst.) trees during their recovery from five years of recurrent summer droughts. In the Kranzberg Forest Roof Experiment (KROOF), precipitation throughfa...The ability of trees to recover functionality during post drought events is an important factor for tree survival and productivity. To elucidate the resilience of carbon (C) transport and the role of C allocation during post-drought recovery, we performed a whole-tree 13C labeling experiment on c. 70-year-old Norway spruce (Picea abies [L.] Karst.) trees during their recovery from five years of recurrent summer droughts. In the Kranzberg Forest Roof Experiment (KROOF), precipitation throughfall was completely excluded during the entire growing season between 2014 and 2018 to expose spruce trees to repeated summer droughts. Repetitive seasonal drought caused significant negative impacts on tree productivity, including reduced total needle surface area, stem growth, and fine root growth. To investigate recovery processes, the drought stressed trees were watered in the early summer of 2019. In parallel with the watering, we conducted whole canopy 13C labeling and traced the fate of newly assimilated C to relevant above- and belowground C sinks. Directly after drought release, the speed of C transport from the canopy to the soil CO2 efflux remained lower in trees that had experienced a previous drought stress compared to controls, but previously stressed trees fully recovered to the control level within two weeks. Hence, whole-tree C transport was resilient to repeated and prolonged drought events. Furthermore, the previously drought-stressed trees preferentially allocated newly assimilated C into belowground sinks, especially into fine and coarse-root growth, to meet the high C demand of growth after drought release. Accordingly, C allocation into aboveground sinks significantly decreased in previously drought stressed trees. The observed high resilience of C transport and the preferential C allocation towards belowground sinks both supported the regrowth of the water-absorbing fine root system. Considering predicted frequent drought events in the future, the fast physiological recovery and responses of the C supply system are essential for Norway spruce forests to regain their productivity after drought release.» weiterlesen» einklappen
Autoren
Klassifikation
DDC Sachgruppe:
Naturwissenschaften
