EGU24-8023, updated on 08 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Carbon recalcitrance and stabilization processes vary across mangrove eco-geomorphologies

Marion Maceiras1, Marie Arnaud1, Catherine Lovelock2, Alex Pearse2, Huyen Dang3, Sarah Robin4, Cyril Marchand4, Axel Felbacq1, Samuel Abiven5,6, Johanne Lebrun Thauront5, Nicolas Bottinelli1, Amrit kumar Mishra7, Syed Hilal Farooq8, Tuhin Bhadra9, and Cornelia Rumpel1
Marion Maceiras et al.
  • 1CNRS, Sorbonne Université, INRAE, Institute of Ecology and Environmental Sciences (IEES), Paris, France
  • 2School of Biological Sciences, The University of Queensland, Brisbane, Australia
  • 3Faculty of Geology and Petroleum Engineering, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh, Vietnam
  • 4Institut de Sciences Exactes et Appliquées (ISEA EA7484), Université de la Nouvelle-Calédonie, Nouméa, New Caledonia
  • 5École normale supérieure, Laboratoire de Géologie, Département de Géosciences, PSL University, Institut Pierre Simon Laplace, Paris, France
  • 6CEREEP-Ecotron Ile De France, ENS, CNRS, PSL University, St-Pierre-lès-Nemours, France
  • 7Centre for Tropical Water & Aquatic Ecosystem Research (TropWater), James Cook University, Townsville, Australia
  • 8School of Earth Ocean and Climate Sciences, Indian Institute of Technology, Bhubaneswar, Odisha, India
  • 9Department of Geography, School of Basic and Applied Sciences, Adamas University, Kolkata, India

Mangrove ecosystems are one of the most carbon dense ecosystems worldwide. Yet, the stabilization and recalcitrance of carbon (C) and organic matter (OM) are little understood in mangroves, especially across eco-geomorphological settings and depths. Here, we characterized the sediment C and OM of Indo-Pacific mangroves, located in four distinct eco-geomorphological settings (i.e., delta, estuary, non-carbonated open coast, carbonated open coast) and at two different depths (i.e., 0-20 cm and 80-100 cm). We quantified the fraction of C within (i) mineralized associated organic matter (MAOM), and (ii) within particulate organic matter (POM). We coupled these analyses with lignin quantity and composition, as well as stable C isotopes analysis in mangrove sediments.

We found significant variation in the quantity of MAOM and POM across mangrove eco-geomorphological settings, but not across mangrove sediment depths. The terrigenous deltaic mangrove exhibited up to three times more MAOM than the carbonate open coast mangrove, which was dominated by POM. Mangroves of the carbonate coast type had higher C content than other eco-geomorphic types. The  was not different across mangrove eco-geomorphologies, but was different across mangrove sediment depths. Regarding OM recalcitrance, the lignin content displayed strong variations across the different eco-geomorphologies, however, there was no clear pattern of lignin degradation stage across depths. Finally, an inverse correlation between sediment C recalcitrance (i.e., lignin content) and stabilization (MAOM) processes were determined across mangroves.

Our findings suggest that the processes leading to OM preservation differ among mangroves in various eco-geomorphological settings. Those results have important implications to guide mangrove restoration for carbon persistence and to model carbon pools across mangrove areas.

How to cite: Maceiras, M., Arnaud, M., Lovelock, C., Pearse, A., Dang, H., Robin, S., Marchand, C., Felbacq, A., Abiven, S., Lebrun Thauront, J., Bottinelli, N., Mishra, A. K., Hilal Farooq, S., Bhadra, T., and Rumpel, C.: Carbon recalcitrance and stabilization processes vary across mangrove eco-geomorphologies, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8023,, 2024.