Mangrove distribution and diversity during three Cenozoic thermal maxima in the Northern Hemisphere (pollen records from the Arctic–North Atlantic–Mediterranean regions)

• Published in: Journal of Biogeography
• Main Authors: Popescu, Speranta‐maria, Suc, Jean‐pierre, Fauquette, Séverine, Bessedik, Mostefa, Jiménez‐moreno, Gonzalo, Robin, Cécile, Labrousse, Loïc
• Other Authors: GeoBioStratData.Consulting, Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS), Université d'Oran 1 Ahmed Ben Bella Oran, Universidad de Granada = University of Granada (UGR), Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), IODP-France, Total S.A., Université de Rennes 1, Université Sorbonne Paris Cité, ANR-11-BS56-0031,PYRAMID,Le Nord des Pyrénées: évaluation intégrée de l'histoire de la Migration des fluides, l'Inversion du rift, le rôle des processus de surface et la Déformation dans un (rétro)prisme orogénique.(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy; Arctic; Nypa; Pacific; Global warming; North Atlantic
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03349012; https://hal-insu.archives-ouvertes.fr/insu-03349012/document; https://hal-insu.archives-ouvertes.fr/insu-03349012/file/Popescu%20et%20al.,%20Journal%20of%20Biogeography,%202021,%20fichier%20accept%C3%A9.pdf; https://doi.org/10.1111/jbi.14238

International audience AimPast pollen records reveal the changes in latitudinal distribution of plants in relation to climate, particularly their expansion in response to global warming. The maximum northward expansion of the mangrove genus Avicennia since the Early Eocene is known, but this information is missing for other mangrove taxa. Here, we evaluate the diversity of past mangroves with respect to latitude during three Cenozoic thermal maxima (PETM: 56 Ma; EECO: 54–49 Ma; MMCO: 17–14 Ma).LocationNorth Atlantic, Mediterranean.TaxaAvicennia, other mangrove taxa (Rhizophoraceae, Nypa, Xylocarpus, Pelliciera, etc.).MethodWe collected well-dated marine sediments along a Northern Hemisphere latitudinal transect and we analysed their pollen content in order to compare the past distribution of mangrove taxa with the present. The analysis of 89 samples (PETM: 13; EECO: 31; MMCO: 45) was performed and interpreted using a robust botanical background for identification of pollen grains and their representativeness in marine sediments.ResultsDuring the Early Eocene, two palaeolatitudinal thresholds at 65–70°N and 35°N, respectively, delimited the Avicennia-only mangrove from a diversified but scrawny mangrove and finally from a diversified and well-developed mangrove. The Avicennia threshold was selective at 40°N during the Mid-Miocene. The Avicennia range limit was up to 10–15° poleward of the limit for other mangrove taxa during the Early Eocene and the Mid-Miocene compared with 9° at present.Main conclusionsA buffer zone characterised by a diversified but scrawny mangrove co-occurring with a few megathermal plants occurred in the Early Eocene between 35°N and 65–70°N. This finding questions the relative influence of a more ‘equable’ climate and/or the ability of some taxa to expand towards areas with cooler conditions in the past. Mangrove provincialism, which was established progressively after the Early Eocene, was probably forced by plate tectonics. The taxonomic impoverishment of the Atlantic East Pacific ...