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Projekt Druckansicht

Verbesserte Abschätzung der Bruttoprimärproduktion

Antragsteller Dr. Tarek El-Madany, seit 9/2021
Fachliche Zuordnung Ökologie und Biodiversität der Pflanzen und Ökosysteme
Biochemie und Biophysik der Pflanzen
Geodäsie, Photogrammetrie, Fernerkundung, Geoinformatik, Kartographie
Pflanzenphysiologie
Förderung Förderung von 2018 bis 2021
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 404943228
 
Erstellungsjahr 2022

Zusammenfassung der Projektergebnisse

The aim of the project was to reduce the uncertainties of current estimates of carbon uptake by vegetation and ecosystem respiration. The approach is based on a combination of carbonyl sulphide (COS) exchange measurements and sun-induced chlorophyll fluorescence (SIF). The COS measurements describe the diffusive transport of CO2 through the stomata into the leaves and SIF measurements describe the energy-providing component of leaf photosynthesis. First, the leaf relative uptake rate (LRU) of COS compared to CO2 was quantified under real measurement conditions and shown to be much more variable than previously assumed by the scientific community. The reason for the variability is that under different environmental conditions the conductivity of COS into the stomata is not identical to the conductivity of CO2. This variability in LRU has a direct impact on the quantification of carbon uptake by vegetation using COS measurements. The relationship between SIF and GPP is not always the same, but is modulated by the release of heat, the so-called non-photochemical quenching (NPQ). Under great stress, e.g. heat or lack of water, when NPQ takes over a large part of the energy release, the relationship between SIF and GPP can even be reversed. Our results show that a joint determination of photochemical reflectance index (PRI) and NPQ help to achieve a better estimation of GPP using satellite-based SIF measurements. Both of the above results can be seen as "surprises", as they add unexpected insights to previous findings. In 2021, a report on the contribution of the Austrian partners to the project was broadcast on Austrian TV.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

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