Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities
In the current context of global change, understanding the interactions between Human/Environment/Climate is necessary to develop adaptive strategies and preserve ecosystems. A retrospective approach is therefore realized in three lacustrine cores to reconstruct the paleo-environmental history durin...
Main Author: | |
---|---|
Other Authors: | , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
Published: |
HAL CCSD
2015
|
Subjects: | |
Online Access: | https://theses.hal.science/tel-01682886 https://theses.hal.science/tel-01682886/document https://theses.hal.science/tel-01682886/file/these_A_GUILLEMOT_Typhaine_2015.pdf |
id |
ftunivnantes:oai:HAL:tel-01682886v1 |
---|---|
record_format |
openpolar |
spelling |
ftunivnantes:oai:HAL:tel-01682886v1 2023-05-15T16:30:30+02:00 Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities Réponses sédimentaires et moléculaires des remplissages lacustres groenlandais aux changements climatiques holocènes et à l'évolution des pratiques agropastorales Guillemot, Typhaine Laboratoire Chrono-environnement (UMR 6249) (LCE) Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC) Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC) Université de Franche-Comté Hervé Richard Vincent Bichet 2015-12-04 https://theses.hal.science/tel-01682886 https://theses.hal.science/tel-01682886/document https://theses.hal.science/tel-01682886/file/these_A_GUILLEMOT_Typhaine_2015.pdf fr fre HAL CCSD NNT: 2015BESA2034 tel-01682886 https://theses.hal.science/tel-01682886 https://theses.hal.science/tel-01682886/document https://theses.hal.science/tel-01682886/file/these_A_GUILLEMOT_Typhaine_2015.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-01682886 Ecologie, Environnement. Université de Franche-Comté, 2015. Français. ⟨NNT : 2015BESA2034⟩ Greenland Holocene Climate change Lake sediments Pastoral activity Groenland Holocène Changement climatique Sédiments lacustres Activité agro-pastorale [SDV.EE]Life Sciences [q-bio]/Ecology environment info:eu-repo/semantics/doctoralThesis Theses 2015 ftunivnantes 2023-03-08T06:28:59Z In the current context of global change, understanding the interactions between Human/Environment/Climate is necessary to develop adaptive strategies and preserve ecosystems. A retrospective approach is therefore realized in three lacustrine cores to reconstruct the paleo-environmental history during the last five millennia. Lake Igaliku (N61°00’22’’, W45°26’28’’), located at 2km from the medieval episcopal cathedral in the historical farming center, has a sedimentation mainly driven by anthropogenic activities. A complete molecular inventory has been made on this sequence to characterize past agropastoral dynamics and their impacts on south Greenlandic ecosystems. The identified fecal biomarkers revealed two agropastoral phases, during the Norse settlement and recently, separated by the Little Ice Age (LIA) and mainly characterized by sheep breeding. Vegetation molecular biomarkers (n-alkanes, triterpenyl acetates) and palynological data showed a reduction of trees and shrubs cover during these two periods especially. Erosion biomarkers (TTHCs) and sedimentological data identified only one drastic erosion in the 1980s synchronous with the mechanized creation of fodder parcels. Moreover, an eutrophication of the lake waters was recorded with short chain length n-alkanes and mesotrophic diatoms. Lake Qallimiut (N60°43’27’’, W45°23’12’’) and Little Kangerluluup (N60°38’32’’, W45°38’11’’), less impacted by anthropogenic activities, are fed by major streams influenced by hydrological variations. Their sedimentation is therefore mainly driven by climate changes. To improve the temporal and spatial resolution of climate changes during the Holocene, a multi-proxy sedimentological study was made on these two sites. Petrophysical, mineralogical and geochemical analyses have identified flood events especially occurring during cooler and wetter periods such as the Middle to Late Holocene transition (ca. 2500 BC), the Sub-boreal/Sub-atlantic transition (ca. 700 BC) and the LIA (between ca. AD 1300 et ca. AD 1900). These ... Doctoral or Postdoctoral Thesis Greenland greenlandic Groenland groenlandais Igaliku Université de Nantes: HAL-UNIV-NANTES Greenland Igaliku ENVELOPE(-45.421,-45.421,60.988,60.988) Qallimiut ENVELOPE(-45.333,-45.333,60.700,60.700) |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
French |
topic |
Greenland Holocene Climate change Lake sediments Pastoral activity Groenland Holocène Changement climatique Sédiments lacustres Activité agro-pastorale [SDV.EE]Life Sciences [q-bio]/Ecology environment |
spellingShingle |
Greenland Holocene Climate change Lake sediments Pastoral activity Groenland Holocène Changement climatique Sédiments lacustres Activité agro-pastorale [SDV.EE]Life Sciences [q-bio]/Ecology environment Guillemot, Typhaine Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
topic_facet |
Greenland Holocene Climate change Lake sediments Pastoral activity Groenland Holocène Changement climatique Sédiments lacustres Activité agro-pastorale [SDV.EE]Life Sciences [q-bio]/Ecology environment |
description |
In the current context of global change, understanding the interactions between Human/Environment/Climate is necessary to develop adaptive strategies and preserve ecosystems. A retrospective approach is therefore realized in three lacustrine cores to reconstruct the paleo-environmental history during the last five millennia. Lake Igaliku (N61°00’22’’, W45°26’28’’), located at 2km from the medieval episcopal cathedral in the historical farming center, has a sedimentation mainly driven by anthropogenic activities. A complete molecular inventory has been made on this sequence to characterize past agropastoral dynamics and their impacts on south Greenlandic ecosystems. The identified fecal biomarkers revealed two agropastoral phases, during the Norse settlement and recently, separated by the Little Ice Age (LIA) and mainly characterized by sheep breeding. Vegetation molecular biomarkers (n-alkanes, triterpenyl acetates) and palynological data showed a reduction of trees and shrubs cover during these two periods especially. Erosion biomarkers (TTHCs) and sedimentological data identified only one drastic erosion in the 1980s synchronous with the mechanized creation of fodder parcels. Moreover, an eutrophication of the lake waters was recorded with short chain length n-alkanes and mesotrophic diatoms. Lake Qallimiut (N60°43’27’’, W45°23’12’’) and Little Kangerluluup (N60°38’32’’, W45°38’11’’), less impacted by anthropogenic activities, are fed by major streams influenced by hydrological variations. Their sedimentation is therefore mainly driven by climate changes. To improve the temporal and spatial resolution of climate changes during the Holocene, a multi-proxy sedimentological study was made on these two sites. Petrophysical, mineralogical and geochemical analyses have identified flood events especially occurring during cooler and wetter periods such as the Middle to Late Holocene transition (ca. 2500 BC), the Sub-boreal/Sub-atlantic transition (ca. 700 BC) and the LIA (between ca. AD 1300 et ca. AD 1900). These ... |
author2 |
Laboratoire Chrono-environnement (UMR 6249) (LCE) Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC) Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC) Université de Franche-Comté Hervé Richard Vincent Bichet |
format |
Doctoral or Postdoctoral Thesis |
author |
Guillemot, Typhaine |
author_facet |
Guillemot, Typhaine |
author_sort |
Guillemot, Typhaine |
title |
Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
title_short |
Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
title_full |
Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
title_fullStr |
Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
title_full_unstemmed |
Sedimentological and molecular responses of Greenlandic lakes to Holocene climate changes and pastoral activities |
title_sort |
sedimentological and molecular responses of greenlandic lakes to holocene climate changes and pastoral activities |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://theses.hal.science/tel-01682886 https://theses.hal.science/tel-01682886/document https://theses.hal.science/tel-01682886/file/these_A_GUILLEMOT_Typhaine_2015.pdf |
long_lat |
ENVELOPE(-45.421,-45.421,60.988,60.988) ENVELOPE(-45.333,-45.333,60.700,60.700) |
geographic |
Greenland Igaliku Qallimiut |
geographic_facet |
Greenland Igaliku Qallimiut |
genre |
Greenland greenlandic Groenland groenlandais Igaliku |
genre_facet |
Greenland greenlandic Groenland groenlandais Igaliku |
op_source |
https://theses.hal.science/tel-01682886 Ecologie, Environnement. Université de Franche-Comté, 2015. Français. ⟨NNT : 2015BESA2034⟩ |
op_relation |
NNT: 2015BESA2034 tel-01682886 https://theses.hal.science/tel-01682886 https://theses.hal.science/tel-01682886/document https://theses.hal.science/tel-01682886/file/these_A_GUILLEMOT_Typhaine_2015.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766020220471738368 |