Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene
Ongoing climate change is causing and will continue to cause significant changes in the structure and biodiversity of forest ecosystems. Boreal forests, which are among the world's largest forest biomes (32% of the world's forest cover), are particularly affected by such changes. Fires are...
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ftccsdartic:oai:HAL:tel-02542715v1 2023-05-15T18:30:46+02:00 Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene Histoire des feux, dynamique de la végétation et variabilité climatique de l’Holocène en République de Komi Barhoumi, Chéïma 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 Montpellier Odile Peyron Ahmed Adam Ali 2019-11-18 https://tel.archives-ouvertes.fr/tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715/document https://tel.archives-ouvertes.fr/tel-02542715/file/2019_BARHOUMI_archivage.pdf fr fre HAL CCSD NNT: 2019MONTG055 tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715/document https://tel.archives-ouvertes.fr/tel-02542715/file/2019_BARHOUMI_archivage.pdf info:eu-repo/semantics/OpenAccess https://tel.archives-ouvertes.fr/tel-02542715 Ecologie, Environnement. Université Montpellier, 2019. Français. ⟨NNT : 2019MONTG055⟩ Boreal ecosystems Fire Paleoclimate Biomarker Russia Holocene Forêts boréales Feux Paléoclimats Biomarqueurs Russie Holocène [SDV.EE]Life Sciences [q-bio]/Ecology environment info:eu-repo/semantics/doctoralThesis Theses 2019 ftccsdartic 2021-11-21T00:53:52Z Ongoing climate change is causing and will continue to cause significant changes in the structure and biodiversity of forest ecosystems. Boreal forests, which are among the world's largest forest biomes (32% of the world's forest cover), are particularly affected by such changes. Fires are major perturbators and contribute to the dynamics of these forests. The recent increase in fire activity in these ecosystems raises ecological and socio-economic issues. The consequences of global warming are already being observed in these regions, particularly in Canada and Russia, where warmer winters and springs (2 to 3°C increase) have been recorded since the 1960s. In addition, ongoing climate change is reversing the net carbon storage of boreal forests, which now appears to be shifting from their carbon sink state to a carbon source state. In order to better understand the mechanisms underlying the functioning of this type of forest, and to anticipate future changes, the study of its past dynamics allows us to provide some answers. The aim of this phD is to study and understand the interactions between the dynamics of Holocene fire, vegetation and climate (last 11700 years) in the Republic of Komi, a region of Russia, where these questions have been very poorly documented. Vegetation dynamics during the Holocene were reconstructed from pollen grain analysis and the REVALS model. An open light forest (a particular type of boreal forest) developed in the early Holocene, from 10,000 to 6,000 cal. yr BP. Then, from 10000 to 3500 cal. yr BP, a dark taiga settled. Then from 3500 cal. yr BP, we observe the gradual return of the light taiga. Paleoclimatic reconstructions based on a dual approach, pollen and molecular biomarkers (brGDGts), have shown a climatic optimum between 7000 and 4000 cal. yr BP. The relationship between these results led us to conclude that for the first half of the Holocene, climate had a major influence on vegetation. Then from 3500 cal. yr BP, the change in fire frequency below a threshold value (FRI, ... Doctoral or Postdoctoral Thesis taiga Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Canada |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
French |
topic |
Boreal ecosystems Fire Paleoclimate Biomarker Russia Holocene Forêts boréales Feux Paléoclimats Biomarqueurs Russie Holocène [SDV.EE]Life Sciences [q-bio]/Ecology environment |
spellingShingle |
Boreal ecosystems Fire Paleoclimate Biomarker Russia Holocene Forêts boréales Feux Paléoclimats Biomarqueurs Russie Holocène [SDV.EE]Life Sciences [q-bio]/Ecology environment Barhoumi, Chéïma Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
topic_facet |
Boreal ecosystems Fire Paleoclimate Biomarker Russia Holocene Forêts boréales Feux Paléoclimats Biomarqueurs Russie Holocène [SDV.EE]Life Sciences [q-bio]/Ecology environment |
description |
Ongoing climate change is causing and will continue to cause significant changes in the structure and biodiversity of forest ecosystems. Boreal forests, which are among the world's largest forest biomes (32% of the world's forest cover), are particularly affected by such changes. Fires are major perturbators and contribute to the dynamics of these forests. The recent increase in fire activity in these ecosystems raises ecological and socio-economic issues. The consequences of global warming are already being observed in these regions, particularly in Canada and Russia, where warmer winters and springs (2 to 3°C increase) have been recorded since the 1960s. In addition, ongoing climate change is reversing the net carbon storage of boreal forests, which now appears to be shifting from their carbon sink state to a carbon source state. In order to better understand the mechanisms underlying the functioning of this type of forest, and to anticipate future changes, the study of its past dynamics allows us to provide some answers. The aim of this phD is to study and understand the interactions between the dynamics of Holocene fire, vegetation and climate (last 11700 years) in the Republic of Komi, a region of Russia, where these questions have been very poorly documented. Vegetation dynamics during the Holocene were reconstructed from pollen grain analysis and the REVALS model. An open light forest (a particular type of boreal forest) developed in the early Holocene, from 10,000 to 6,000 cal. yr BP. Then, from 10000 to 3500 cal. yr BP, a dark taiga settled. Then from 3500 cal. yr BP, we observe the gradual return of the light taiga. Paleoclimatic reconstructions based on a dual approach, pollen and molecular biomarkers (brGDGts), have shown a climatic optimum between 7000 and 4000 cal. yr BP. The relationship between these results led us to conclude that for the first half of the Holocene, climate had a major influence on vegetation. Then from 3500 cal. yr BP, the change in fire frequency below a threshold value (FRI, ... |
author2 |
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 Montpellier Odile Peyron Ahmed Adam Ali |
format |
Doctoral or Postdoctoral Thesis |
author |
Barhoumi, Chéïma |
author_facet |
Barhoumi, Chéïma |
author_sort |
Barhoumi, Chéïma |
title |
Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
title_short |
Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
title_full |
Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
title_fullStr |
Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
title_full_unstemmed |
Fire history, vegetation and climate dynamic of the Republic of Komi during the Holocene |
title_sort |
fire history, vegetation and climate dynamic of the republic of komi during the holocene |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://tel.archives-ouvertes.fr/tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715/document https://tel.archives-ouvertes.fr/tel-02542715/file/2019_BARHOUMI_archivage.pdf |
geographic |
Canada |
geographic_facet |
Canada |
genre |
taiga |
genre_facet |
taiga |
op_source |
https://tel.archives-ouvertes.fr/tel-02542715 Ecologie, Environnement. Université Montpellier, 2019. Français. ⟨NNT : 2019MONTG055⟩ |
op_relation |
NNT: 2019MONTG055 tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715 https://tel.archives-ouvertes.fr/tel-02542715/document https://tel.archives-ouvertes.fr/tel-02542715/file/2019_BARHOUMI_archivage.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766214356210548736 |