Project

Back to overview

Minimum levels of carbon reserves in temperate trees at severe carbon limitation and drought stress (Acronym: MinCarbRes)

Applicant Hoch Günter
Number 156944
Funding scheme Project funding (Div. I-III)
Research institution Botanisches Institut Universität Basel
Institution of higher education University of Basel - BS
Main discipline Ecology
Start/End 01.02.2015 - 31.07.2018
Approved amount 307'776.00
Show all

All Disciplines (4)

Discipline
Ecology
Environmental Research
Botany
Biochemistry

Keywords (8)

trees; carbohydrates; non-structural carbon reserves; carbon starvation; source-sink balance; 13C labeling; forest ecology; drought stress

Lay Summary (German)

Lead
Die Ökophysiologie der Kohlenstoffspeicherung in Bäumen ist bisher unzureichend untersucht. Dieses Projekt soll dazu Beitragen, biologische Regelmechanismen der Speicherung von Kohlenstoffreserven in verholzten Geweben zu verstehen. Darüber hinaus wird in einer experimentellen Studie die Bedeutung von Kohlenstoffreserven für das Überleben von Bäumen unter Trockenstress untersucht. Die Ergebnisse dieses Projektes werden wichtige Erkenntnisse zur Ökologie europäischer Baumarten in einer CO2-reichen, trockeneren Zukunft liefern.
Lay summary

Die Analyse von Kohelnstoff(C)-Reservekonzentrationen (vor allem Stärke und freie Zucker) in pflanzlichem Gewebe wurde in den letzten Jahren zunehmend dazu verwendet um Aussagen über die aktuelle C-Versorgung von Pflanzen zu treffen. Diesem Ansatz stehen aber vor allem in mehrjährigen, verholzten Arten grosse Wissenslücken bezüglich der physiologischen Kontrolle von C-Speicherung und der Funktion von C-Reserveverbindungen gegenüber. Unser bisheriges Konzept von C-Reserven in Bäumen entspricht generell dem eines 'Überlaufbeckens' für Photoassimilate, dessen Poolgrösse alleine durch die Aktivität von Photosynthese auf der einen Seite und von C-verbrauchenden Prozessen (Atmung, Wachstum, etc.) auf der anderen Seite bestimmt wird. Dieses Projekt wird Hinweise darauf liefern, ob und zu welchem Ausmass C-Reserven in Bäumen auch entgegen dem laufenden C-Bedarf anderer Prozesse akkumuliert werden.

Wir untersuchen die zeitliche Dynamik der C-Speicherung in Bäumen und gehen im Besonderen der Frage nach, welche Auswirkungen eine Limitation der photosynthetischen Assimilation auf die Grösse und die Zusammensetzung von C-Reserven in verholzten Geweben hat. Erst wenn die organspezifischen Minimalkonzentrationen von C-Reserven unter C-Limitation bekannt sind, können quantitative Analysen dieser Verbindungen eindeutig Aussagen darüber liefern, ob eine untersuchte Pflanze unter C-Limitation leidet oder nicht. In einem zusätzlichen Trockenstress-Experiment wird die Rolle von C-Reserven für das Überleben von Bäumen unter Wassermangel untersucht.

Wissenschaftlicher und gesellschaftlicher Kontext
Die Ergebnisse dieses Projektes werden dazu beitragen grundsätzliche Fragen zur Regulation und Funktion von C-Reserven in Bäumen zu beantworten. Durch Einbezug möglichst vieler europäischer Forstbaumarten werden die Forschungsergebnisse vor allem in Hinblick auf zukünftige Klimaänderungen auch relevante Informationen für Forstwirtschaft und Waldmanagement liefern.

Direct link to Lay Summary Last update: 03.11.2014

Responsible applicant and co-applicants

Employees

Publications

Publication
High carbon storage in carbon‐limited trees
Weber Raphael, Gessler Arthur, Hoch Günter (2018), High carbon storage in carbon‐limited trees, in New Phytologist, nph.15599-nph.15599.
Living on next to nothing: tree seedlings can survive weeks with very low carbohydrate concentrations
Weber Raphael, Schwendener Andrea, Schmid Sandra, Lambert Savoyane, Wiley Erin, Landhäusser Simon M., Hartmann Henrik, Hoch Günter (2018), Living on next to nothing: tree seedlings can survive weeks with very low carbohydrate concentrations, in New Phytologist, 218(1), 107-118.

Collaboration

Group / person Country
Types of collaboration
Prof. Dr. Simon Landhaeusser, University of Alberta Canada (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Henrik Hartmann, Max Plack Institute for Biogeochemistry, Jena Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Botanical Colloquium at the University of Basel Individual talk Minimum levels and dynamics of carbon reserves in temperate trees at severe carbon limitation 24.05.2018 Basel, Switzerland Weber Raphael;
BES/GfÖ Joint Meeting 2017 Poster Trees in deep shade save their carbon 11.12.2017 Gent, Belgium Hoch Günter; Weber Raphael;
European dendrological fieldweek Talk given at a conference Shaded trees save their carbon 10.09.2017 Kranjska Gora, Slovenia Weber Raphael;
EGU Annual Meeting 2017 Poster Shaded trees save their carbon 24.04.2017 Vienna, Austria Hoch Günter; Weber Raphael;
Swiss Global Change Day 2017 Poster Shaded trees save their carbon 11.04.2017 Bern, Switzerland Weber Raphael; Hoch Günter;
Special colloquium on carbon reserves, Weizmann Institute Individual talk Controls and functions of non-structural carbon reserves in trees 07.02.2017 Rehovot, Israel Schmid Sandra; Hoch Günter; Weber Raphael;
PSC Zürich-Basel Symposium 2016 Poster Controls of carbon reserves in temperate trees at long-term carbon limitation 01.12.2016 Zürich, Switzerland Weber Raphael; Hoch Günter;
ESA Annual Meeting 2016 Talk given at a conference Carbon limitation and starvation in trees: Controls and functions of non-structural carbon reserves 07.08.2016 Sacramento, United States of America Weber Raphael; Hoch Günter;
EGU Annual Meeting 2016 Poster How low can you go? Minimum levels of NSC in carbon limited tree saplings 18.04.2016 Vienna, Austria Hoch Günter;
Swiss Global Change Day 2016 Poster Controls of carbon reserves in temperate trees at long-term carbon limitation 12.04.2016 Bern, Switzerland Weber Raphael; Hoch Günter;
Swiss Plant Science Web Meeting 2016 Poster Do carbon reserves concentrations really indicate the carbon balance of trees? 25.01.2016 Les Diablerets, Switzerland Hoch Günter;
NLU Kolloquium Talk given at a conference Der Kohlenstoff-Haushalt von Bäumen im Klimawandel 09.11.2015 Basel, Switzerland Hoch Günter;
GfÖ Annual Meeting 2015, Göttingen Talk given at a conference Do carbon reserve concentrations really indicate the carbon balance of trees? 31.08.2015 Göttingen, Germany Hoch Günter;


Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
Fachaustausch in Biologie für Gymnasiallehrer beider Basel Talk 15.09.2016 University of Basel, Switzerland Hoch Günter;


Awards

Title Year
European Geophysical Union (EGU): Outstanding student poster award 2017

Abstract

A detailed understanding of the carbon (C)-relations of trees is key to understand their physiological reaction to climatic change and the associated changes in biochemical cycles at the local and global scale. An increasing number of studies are using carbon reserve concentrations of plant tissues as proxies for a plant's net C balance. Especially with respect to the effect of environmental stress like drought, analyses of non-structural carbohydrates (NSC) reserves have been frequently used to assess the absences or presence of C-limitation for growth and survival of trees, assuming that NSC concentrations are largely mirroring C-over or -undersupply. However, recent research questioned the indicative value of C reserve concentrations for a plant's C-relation, emphasizing the active nature of reserve formation, which can also occur against prevailing C-sink demands, and thus might be in direct competition with growth. Within this research project we will address fundamental, but so far largely unexplored questions regarding the dynamic of C storage in trees to better assess the potential of C reserve tissue concentrations as indicators of a plant's C balance.In detail, we are aiming to (1) monitor the effects of severe shading on growth and C storage of tree saplings by sequential harvests over the course of 2.5 years, in order to identify the reaction of non-structural C reserves to long-term C-limitation and to identify possible trade-offs between growth and storage. To arrive at general patterns and identify species-specific differences, we will investigate different tissues of 10 temperate tree species form 5 different functional types. In an additional experiment, we will (2) investigate the absolute minimum concentrations of different C reserve compounds (NSC and lipids, but also cell-wall hemicelluloses as potential reserves) by exposing saplings of four different species (two deciduous broad-leaved, two evergreen conifers) to either continuous darkness or repeated defoliation until the death of the saplings due to C-starvation. Finally, (3) after one growing season, a subset of shaded and un-shaded trees from the long-term shading experiment will be treated with continuous drought, in order to test the significance of the initial C reserve tissue concentrations for the survival of tree saplings under hydraulic stress. This experiment will again use two deciduous broad-leaved and two evergreen conifer species. In addition, we will apply 13C-pulse labeling at different dates into drought to assess the effect of hydraulic constraints on the phloem transport of current photoassimilates and the persistence of newly formed C-reserves under drought.The experiments planned for this project will deliver very basic information that has not been addressed systematically so far. The project will significantly contribute to close a major gap in our understanding of the C relations and C reserve dynamics in trees. The main applicant, Günter Hoch, and the co-applicant, Arthur Gessler, are both established researchers in the field of the ecophysiology of C reserves and stress physiology of plants. This project will further run in collaboration with the research group of Prof. Simon Landhäusser, University of Alberta, Canada, who will simultaneously perform complementary experiments on the C reserve dynamics of aspen trees under C-limitation. Because the comparative analyses of C reserve tissue concentrations has become a widely used tool to asses the C relations of plants, the gained knowledge on the physiological minimum values of C reserve concentrations, possible growth-storage trade-offs under C-limitation, and the significance of C reserves for drought survival, will be of prime importance for all researches working on the C dynamics of plants, especially with respect to climate change effects. The comparison of several species and functional tree types will further deliver implications for our understanding of climate-driven species distribution and forest composition, and the deriving consequences for the ecosystem fluxes of C, water and nutrients.
-