Rhizosphere activity in an old-growth forest reacts rapidly to changes in soil moisture and shapes whole-tree carbon allocation
Autor: | Matthias Haeni, Günter Hoch, Benjamin Stern, Willy Werner, Ansgar Kahmen, Bernhard Backes, Ivano Brunner, Jobin Joseph, Jörg Luster, Gerd Gleixner, Decai Gao, Nadine K. Ruehr, Kaisa Rissanen, Thomas Wohlgemuth, Christian Hug, Mai-He Li, Leonie Schönbeck, Roland A. Werner, Marcus Schaub, Frank Hagedorn, Marco M. Lehmann, Arthur Gessler, Andreas Rigling, Frank M. Thomas, Corinne Bloch, Martina Peter, Christian Poll, Matthias Saurer, Henrik Hartmann |
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Přispěvatelé: | Department of Forest Sciences, Ecosystem processes (INAR Forest Sciences), Institute for Atmospheric and Earth System Research (INAR community) |
Rok vydání: | 2020 |
Předmět: |
DYNAMICS
0106 biological sciences IMPACT drought Forests Plant Roots 01 natural sciences Sink (geography) Trees BIOMASS Soil Water content 4112 Forestry Rhizosphere Multidisciplinary geography.geographical_feature_category biology food and beverages Pinus sylvestris sink control Biological Sciences Old-growth forest Droughts CO2 C-|13 pulse labeling Climate Change 010603 evolutionary biology drought release FINE ROOTS Ecosystem SCOTS PINE geography Topsoil PHOTOSYNTHESIS fungi Scots pine Water 15. Life on land SEASONAL-VARIATIONS biology.organism_classification Carbon Plant Leaves Agronomy 13. Climate action Soil water Environmental science RESPONSES 010606 plant biology & botany |
Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proc Natl Acad Sci U S A |
ISSN: | 1091-6490 0027-8424 |
Popis: | Drought alters carbon (C) allocation within trees, thereby impairing tree growth. Recovery of root and leaf functioning and prioritized C supply to sink tissues after drought may compensate for drought -induced reduction of assimilation and growth. It remains unclear if C allocation to sink tissues during and following drought is controlled by altered sink metabolic activities or by the availability of new assimilates. Understanding such mechanisms is required to predict forests' resilience to a changing climate. We investigated the impact of drought and drought release on C allocation in a 100-y-old Scots pine forest. We applied (CO2)-C-13 pulse labeling to naturally dry control and long-term irrigated trees and tracked the fate of the label in aboveand belowground C pools and fluxes. Allocation of new assimilates belowground was ca. 53% lower under nonirrigated conditions. A short rainfall event, which led to a temporary increase in the soil water content (SWC) in the topsoil, strongly increased the amounts of C transported belowground in the nonirrigated plots to values comparable to those in the irrigated plots. This switch in allocation patterns was congruent with a tipping point at around 15% SWC in the response of the respiratory activity of soil microbes. These results indicate that the metabolic sink activity in the rhizosphere and its modulation by soil moisture can drive C allocation within adult trees and ecosystems. Even a subtle increase in soil moisture can lead to a rapid recovery of belowground functions that in turn affects the direction of C transport in trees. |
Databáze: | OpenAIRE |
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