A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate?
International audience Background and Aims: The complexity of fossil forest ecosystems is difficult to reconstruct due to the fragmentary nature of the fossil record. However, detailed morpho-anatomical studies of well-preserved individual fossils can provide key information on tree growth and ecolo...
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ftciradhal:oai:HAL:hal-04647642v1 2024-09-15T17:47:32+00:00 A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? Decombeix, Anne-Laure Hiller, Philipp Bomfleur, Benjamin Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP) Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM) Westfälische Wilhelms-Universität Münster = University of Münster (WWU) 2024-07-10 https://hal.inrae.fr/hal-04647642 https://doi.org/10.1093/aob/mcae106 en eng HAL CCSD Oxford University Press (OUP) info:eu-repo/semantics/altIdentifier/doi/10.1093/aob/mcae106 hal-04647642 https://hal.inrae.fr/hal-04647642 doi:10.1093/aob/mcae106 ISSN: 0305-7364 EISSN: 1095-8290 Annals of Botany https://hal.inrae.fr/hal-04647642 Annals of Botany, In press, ⟨10.1093/aob/mcae106⟩ Paleobotany Triassic Conifer Antarctica Fossil wood Growth-rings Suppressed Greenhouse climate High-latitude Polar forest [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2024 ftciradhal https://doi.org/10.1093/aob/mcae106 2024-07-18T23:35:53Z International audience Background and Aims: The complexity of fossil forest ecosystems is difficult to reconstruct due to the fragmentary nature of the fossil record. However, detailed morpho-anatomical studies of well-preserved individual fossils can provide key information on tree growth and ecology, including in biomes with no modern analog such as the lush forests that developed in the polar regions during past greenhouse climatic episodes. Methods: We describe an unusual-looking stem from Middle Triassic (ca 240 Ma) deposits of Antarctica with over 100 very narrow growth-rings and conspicuous persistent vascular traces through the wood. Sections of the specimen were prepared using the cellulose acetate peel technique to determine its systematic affinities and analyse its growth. Key Results: The new fossil shows similarities with the form genus Woodworthia and with conifer stems from the Triassic of Antarctica, and is assigned to the conifers. Vascular traces are interpreted as those of small branches retained on the trunk. Growth-ring analyses reveal one of the slowest growth rates reported in the fossil record, with an average of 0.2 mm/season. While the tree was growing within the Triassic polar circle, sedimentological data and growth-ring information from other fossil trees, including from the same locality, support the presence of favorable conditions in the region. Conclusions: The specimen is interpreted as a dwarf conifer tree that grew under a generally favorable regional climate but whose growth was suppressed due to stressful local site conditions. This is the first time that a tree with suppressed growth is identified as such in the fossil record, providing new insights on the structure of polar forests under greenhouse climates and, more generally, on the complexity of tree communities in deep time. Article in Journal/Newspaper Antarc* Antarctica CIRAD: HAL (Agricultural Research for Development) Annals of Botany |
institution |
Open Polar |
collection |
CIRAD: HAL (Agricultural Research for Development) |
op_collection_id |
ftciradhal |
language |
English |
topic |
Paleobotany Triassic Conifer Antarctica Fossil wood Growth-rings Suppressed Greenhouse climate High-latitude Polar forest [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] [SDE]Environmental Sciences |
spellingShingle |
Paleobotany Triassic Conifer Antarctica Fossil wood Growth-rings Suppressed Greenhouse climate High-latitude Polar forest [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] [SDE]Environmental Sciences Decombeix, Anne-Laure Hiller, Philipp Bomfleur, Benjamin A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
topic_facet |
Paleobotany Triassic Conifer Antarctica Fossil wood Growth-rings Suppressed Greenhouse climate High-latitude Polar forest [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE] [SDE]Environmental Sciences |
description |
International audience Background and Aims: The complexity of fossil forest ecosystems is difficult to reconstruct due to the fragmentary nature of the fossil record. However, detailed morpho-anatomical studies of well-preserved individual fossils can provide key information on tree growth and ecology, including in biomes with no modern analog such as the lush forests that developed in the polar regions during past greenhouse climatic episodes. Methods: We describe an unusual-looking stem from Middle Triassic (ca 240 Ma) deposits of Antarctica with over 100 very narrow growth-rings and conspicuous persistent vascular traces through the wood. Sections of the specimen were prepared using the cellulose acetate peel technique to determine its systematic affinities and analyse its growth. Key Results: The new fossil shows similarities with the form genus Woodworthia and with conifer stems from the Triassic of Antarctica, and is assigned to the conifers. Vascular traces are interpreted as those of small branches retained on the trunk. Growth-ring analyses reveal one of the slowest growth rates reported in the fossil record, with an average of 0.2 mm/season. While the tree was growing within the Triassic polar circle, sedimentological data and growth-ring information from other fossil trees, including from the same locality, support the presence of favorable conditions in the region. Conclusions: The specimen is interpreted as a dwarf conifer tree that grew under a generally favorable regional climate but whose growth was suppressed due to stressful local site conditions. This is the first time that a tree with suppressed growth is identified as such in the fossil record, providing new insights on the structure of polar forests under greenhouse climates and, more generally, on the complexity of tree communities in deep time. |
author2 |
Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP) Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM) Westfälische Wilhelms-Universität Münster = University of Münster (WWU) |
format |
Article in Journal/Newspaper |
author |
Decombeix, Anne-Laure Hiller, Philipp Bomfleur, Benjamin |
author_facet |
Decombeix, Anne-Laure Hiller, Philipp Bomfleur, Benjamin |
author_sort |
Decombeix, Anne-Laure |
title |
A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
title_short |
A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
title_full |
A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
title_fullStr |
A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
title_full_unstemmed |
A dwarf conifer tree from the Triassic of Antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
title_sort |
dwarf conifer tree from the triassic of antarctica: the first fossil evidence of suppressed growth in a favorable climate? |
publisher |
HAL CCSD |
publishDate |
2024 |
url |
https://hal.inrae.fr/hal-04647642 https://doi.org/10.1093/aob/mcae106 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
ISSN: 0305-7364 EISSN: 1095-8290 Annals of Botany https://hal.inrae.fr/hal-04647642 Annals of Botany, In press, ⟨10.1093/aob/mcae106⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1093/aob/mcae106 hal-04647642 https://hal.inrae.fr/hal-04647642 doi:10.1093/aob/mcae106 |
op_doi |
https://doi.org/10.1093/aob/mcae106 |
container_title |
Annals of Botany |
_version_ |
1810496940715016192 |