Fates of lignin and carbohydrates in Siberian soils
Permafrost-affected soils contain a huge reservoir of organic matter (OM) which, in the past, was largely persistent against microbial decomposition as consequence of cool and waterlogged conditions in the active layer, and freezing in the permafrost layer. Knowing the composition and degree of deco...
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Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
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ftunivhannover:oai:www.repo.uni-hannover.de:123456789/13190 2023-07-16T03:51:12+02:00 Fates of lignin and carbohydrates in Siberian soils Dao, Thi Thao 2022 https://www.repo.uni-hannover.de/handle/123456789/13190 https://doi.org/10.15488/13085 eng eng Hannover : Institutionelles Repositorium der Leibniz Universität Hannover DOI:https://doi.org/10.1016/j.soilbio.2017.10.032 DOI:https://doi.org/10.1029/2020JG006181 http://dx.doi.org/10.15488/13085 https://www.repo.uni-hannover.de/handle/123456789/13190 Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. frei zugänglich Permafrost soil organic matter lignin carbohydrates density fractionation climate change organische Bodensubstanz (OM) Kohlenhydrate Dichtefraktionierung Klimawandel ddc:500 status-type:publishedVersion doc-type:DoctoralThesis doc-type:Text 2022 ftunivhannover https://doi.org/10.15488/1308510.1016/j.soilbio.2017.10.03210.1029/2020JG006181 2023-06-28T10:39:19Z Permafrost-affected soils contain a huge reservoir of organic matter (OM) which, in the past, was largely persistent against microbial decomposition as consequence of cool and waterlogged conditions in the active layer, and freezing in the permafrost layer. Knowing the composition and degree of decomposition at molecular level of soil organic matter (SOM) is relevant to assess their vulnerability under impacts of climate change. This thesis investigated two major constituents of SOM, lignin and carbohydrates, across a west-east gradient in northern Siberia (longitudinal transect) and along a north-south gradient in western Siberia (latitudinal transect), aiming at identifying their fate once permafrost is thawing. The longitudinal transect included three continuous permafrost sites, from Cherskiy (CH) in north-eastern, Logata (LG) in north-central, and Tazovskiy (TZ) in north-western Siberia, which principally differ in active layer thickness and soil mineralogical properties. The latitudinal transect included all major biomes (tundra, taiga, forest steppe and steppe) from arctic to temperate ecosystems, which vary in mean annual temperature (MAT), mean annual precipitation (MAP), vegetation and soil properties. Lignin-derived phenols and neutral sugars within plant and soil samples at each horizon were analysed by CuO oxidation and trifluoroacetic acid (TFA) extraction methods respectively. Along the longitudinal transect, the stage of lignin degradation, appeared to increase from TZ to CH site. The stronger degradation of lignin and neutral sugars at TZ is supposed to be due to the higher MAT and larger active layer thickness, coinciding with better aeration and/or better mobilization of OM. In addition, the larger contents of Fe and Al (hydr)oxides likely additionally stabilized lignin-derived phenols associated with the mineral phase at these sites. With respect to the latitudinal transect, the stage of lignin degradation appeared to increase from tundra to forest steppe, then decrease to steppe. The ... Doctoral or Postdoctoral Thesis Active layer thickness Arctic Cherskiy Climate change permafrost taiga Tundra Siberia Institutional Repository of Leibniz Universität Hannover Arctic Cherskiy ENVELOPE(161.332,161.332,68.753,68.753) Logata ENVELOPE(95.783,95.783,73.208,73.208) |
institution |
Open Polar |
collection |
Institutional Repository of Leibniz Universität Hannover |
op_collection_id |
ftunivhannover |
language |
English |
topic |
Permafrost soil organic matter lignin carbohydrates density fractionation climate change organische Bodensubstanz (OM) Kohlenhydrate Dichtefraktionierung Klimawandel ddc:500 |
spellingShingle |
Permafrost soil organic matter lignin carbohydrates density fractionation climate change organische Bodensubstanz (OM) Kohlenhydrate Dichtefraktionierung Klimawandel ddc:500 Dao, Thi Thao Fates of lignin and carbohydrates in Siberian soils |
topic_facet |
Permafrost soil organic matter lignin carbohydrates density fractionation climate change organische Bodensubstanz (OM) Kohlenhydrate Dichtefraktionierung Klimawandel ddc:500 |
description |
Permafrost-affected soils contain a huge reservoir of organic matter (OM) which, in the past, was largely persistent against microbial decomposition as consequence of cool and waterlogged conditions in the active layer, and freezing in the permafrost layer. Knowing the composition and degree of decomposition at molecular level of soil organic matter (SOM) is relevant to assess their vulnerability under impacts of climate change. This thesis investigated two major constituents of SOM, lignin and carbohydrates, across a west-east gradient in northern Siberia (longitudinal transect) and along a north-south gradient in western Siberia (latitudinal transect), aiming at identifying their fate once permafrost is thawing. The longitudinal transect included three continuous permafrost sites, from Cherskiy (CH) in north-eastern, Logata (LG) in north-central, and Tazovskiy (TZ) in north-western Siberia, which principally differ in active layer thickness and soil mineralogical properties. The latitudinal transect included all major biomes (tundra, taiga, forest steppe and steppe) from arctic to temperate ecosystems, which vary in mean annual temperature (MAT), mean annual precipitation (MAP), vegetation and soil properties. Lignin-derived phenols and neutral sugars within plant and soil samples at each horizon were analysed by CuO oxidation and trifluoroacetic acid (TFA) extraction methods respectively. Along the longitudinal transect, the stage of lignin degradation, appeared to increase from TZ to CH site. The stronger degradation of lignin and neutral sugars at TZ is supposed to be due to the higher MAT and larger active layer thickness, coinciding with better aeration and/or better mobilization of OM. In addition, the larger contents of Fe and Al (hydr)oxides likely additionally stabilized lignin-derived phenols associated with the mineral phase at these sites. With respect to the latitudinal transect, the stage of lignin degradation appeared to increase from tundra to forest steppe, then decrease to steppe. The ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Dao, Thi Thao |
author_facet |
Dao, Thi Thao |
author_sort |
Dao, Thi Thao |
title |
Fates of lignin and carbohydrates in Siberian soils |
title_short |
Fates of lignin and carbohydrates in Siberian soils |
title_full |
Fates of lignin and carbohydrates in Siberian soils |
title_fullStr |
Fates of lignin and carbohydrates in Siberian soils |
title_full_unstemmed |
Fates of lignin and carbohydrates in Siberian soils |
title_sort |
fates of lignin and carbohydrates in siberian soils |
publisher |
Hannover : Institutionelles Repositorium der Leibniz Universität Hannover |
publishDate |
2022 |
url |
https://www.repo.uni-hannover.de/handle/123456789/13190 https://doi.org/10.15488/13085 |
long_lat |
ENVELOPE(161.332,161.332,68.753,68.753) ENVELOPE(95.783,95.783,73.208,73.208) |
geographic |
Arctic Cherskiy Logata |
geographic_facet |
Arctic Cherskiy Logata |
genre |
Active layer thickness Arctic Cherskiy Climate change permafrost taiga Tundra Siberia |
genre_facet |
Active layer thickness Arctic Cherskiy Climate change permafrost taiga Tundra Siberia |
op_relation |
DOI:https://doi.org/10.1016/j.soilbio.2017.10.032 DOI:https://doi.org/10.1029/2020JG006181 http://dx.doi.org/10.15488/13085 https://www.repo.uni-hannover.de/handle/123456789/13190 |
op_rights |
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. frei zugänglich |
op_doi |
https://doi.org/10.15488/1308510.1016/j.soilbio.2017.10.03210.1029/2020JG006181 |
_version_ |
1771545941730394112 |