Projektbeschreibung
Die Rolle der Diazotrophie im Kohlenstoffkreislauf kartieren
Diazotrophe Mikroorganismen unterstützen die Produktivität der Weltmeere, indem sie Stickstoff umwandeln und zu Kohlenstoffsenken beitragen. Es ist jedoch nicht bekannt, wie viel Kohlenstoff aus der Diazotrophie in die Tiefsee gelangt. Diese Frage soll im EU-finanzierten Projekt HOPE beantwortet werden, um so bessere Prognosen zur Rolle der Meere bei der CO2-Sequestrierung und der Eindämmung des Klimawandels zu ermöglichen. Mittels Einzelzell-Isotopentechniken werden die Forschenden diese prokaryotische Kohlenstoffpumpe untersuchen und deren vorübergehenden und saisonalen Eigenschaften bestimmen. In einer geeigneten Wassersäule werden die Forschenden auch untersuchen, wie diazotrophe Mikroorganismen sich ansammeln, absenken und remineralisiert werden. Außerdem wird über eine autonome Messplattform kontrolliert, wie Umweltfaktoren die Wirksamkeit der Pumpe regulieren. Letztendlich führt die Arbeit zu neuen globalen Schätzungen zu dem über Diazotrophie exportierten CO2.
Ziel
Diazotrophs regulate marine productivity in 60% of our oceans by alleviating nitrogen limitation, contributing to carbon (C) sequestration through the N2-primed Prokaryotic C Pump (PCP). Yet we don’t know how much diazotroph-derived organic C (OC) is exported to the deep ocean, which prevents robust predictions of how the ocean contributes to CO2 sequestration and climate change mitigation. This knowledge gap is due to the multiple and complex pathways by which diazotrophs are exported to the deep ocean, which quantification and drivers of variability are impossible to capture with current methods. HOPE will bridge this gap thanks to a new isotopic technique I developed and to a coupling between lab and in situ approaches examining processes occurring at different spatiotemporal scales, and capable of capturing both transient and seasonal features of the PCP. HOPE will: 1.Determine how various diazotrophs aggregate, sink and are remineralized by using an automated experimental water column I designed for this proposal 2.Decipher by which pathways diazotroph-derived OC is exported to the deep ocean thanks to a pioneer approach combining single-cell isotopic analyses, in-depth microbiological characterization of sinking particles and geochemical budgets 3.Investigate how environmental drivers control the whole process, from the surface diazotroph community up to their eventual export to the deep ocean, by deploying a cutting-edge autonomous platform, unique as it performs synoptic measurements both in and below the euphotic zone at high resolution (hourly/daily). In its final stage, HOPE will use the generated data to provide global, spatially resolved estimates of the contribution of diazotrophs to overall OC export. Based on my expertise at the interface between microbial oceanography and geochemistry, HOPE has the potential to deliver a multidisciplinary and ground-breaking knowledge leading to potential scientific-based recommendations to fight climate change.
Wissenschaftliches Gebiet
- natural sciencesearth and related environmental sciencesgeochemistry
- social scienceseconomics and businesseconomicsproduction economicsproductivity
- natural sciencesbiological sciencesecologyecosystems
- natural sciencesearth and related environmental sciencesoceanography
- natural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changes
Programm/Programme
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Thema/Themen
Finanzierungsplan
HORIZON-AG - HORIZON Action Grant Budget-BasedGastgebende Einrichtung
13572 Marseille
Frankreich