Mechanisms of below-ground carbon cycling in subarctic ecosystems
Some components of the below-ground carbon (C) cycle in terrestrial ecosystems are still poorly understood. A better understanding will be necessary to predict adequately the impacts of global change factors on C cycling and storage, especially in high-latitude ecosystems, where much of the C is sto...
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Maria Olsrud, CGB, Lund Sweden
2004
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ftulundlup:oai:lup.lub.lu.se:4e2f3903-16de-4a6c-a77d-7a82f16901cb 2023-05-15T18:28:04+02:00 Mechanisms of below-ground carbon cycling in subarctic ecosystems Olsrud, Maria 2004 https://lup.lub.lu.se/record/467318 eng eng Maria Olsrud, CGB, Lund Sweden https://lup.lub.lu.se/record/467318 urn:isbn:91-974997-0-6 scopus:5144228667 Physical Geography cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi pedology geomorphology subarctic tundra phosphorous mobilization organic acids open top chamber experiment 15N natural abundance Ericoid mycorrhizas global change 14C pulse-labelling Carbon allocation thesis/doccomp info:eu-repo/semantics/doctoralThesis text 2004 ftulundlup 2023-02-01T23:28:19Z Some components of the below-ground carbon (C) cycle in terrestrial ecosystems are still poorly understood. A better understanding will be necessary to predict adequately the impacts of global change factors on C cycling and storage, especially in high-latitude ecosystems, where much of the C is stored below-ground. In this work some of the mechanisms of the below-ground C cycle in subarctic ecosystems were studied and responses to present and potential future environmental conditions assessed. Using 14C pulse-labelling, C allocation to above-ground biomass, rhizomes, coarse roots, fine roots, hair roots, ericoid mycorrhizas, microbes and dissolved organic C (DOC) was determined repeatedly over the growing season in four of the most common vegetation types of the Scandinavian subarctic: (1) Dry dwarf shrub tundra; (2) Semi-wet mire; (3) Wet mire; and (4) the understorey of subarctic birch forest. Effects of increased temperatures, increased atmospheric CO2 concentrations and both factors in combination on below-ground C allocation, ericoid mycorrhizal colonisation and functioning were studied in an full-factorial open-top chamber experiment. Furthermore, responses of ericoid mycorrhizal colonisation rates to environmental variation during the growing season were investigated. Ecosystem C partitioning varied temporally in all studied ecosystems, possibly indicating changes in growth, nutrient uptake or C storage by vegetation. The relative importance of C pools with "fast" versus "slow" turnover rates varied spatially, among vegetation types. Therefore it is important for global change studies to consider the possible effects of vegetation changes on ecosystem C dynamics. Allocation of recent assimilates to fast-turnover C pools such as hair roots and DOC was particularly high in a dwarf shrub tundra making them quantitatively interesting pools to consider in studies of ecosystem C dynamics. Furthermore, a significant proportion of assimilates in the DOC pool were allocated to P-mobilizing organic acids, ... Doctoral or Postdoctoral Thesis Subarctic Tundra Lund University Publications (LUP) |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Physical Geography cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi pedology geomorphology subarctic tundra phosphorous mobilization organic acids open top chamber experiment 15N natural abundance Ericoid mycorrhizas global change 14C pulse-labelling Carbon allocation |
spellingShingle |
Physical Geography cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi pedology geomorphology subarctic tundra phosphorous mobilization organic acids open top chamber experiment 15N natural abundance Ericoid mycorrhizas global change 14C pulse-labelling Carbon allocation Olsrud, Maria Mechanisms of below-ground carbon cycling in subarctic ecosystems |
topic_facet |
Physical Geography cartography climatology Fysisk geografi geomorfologi marklära kartografi klimatologi pedology geomorphology subarctic tundra phosphorous mobilization organic acids open top chamber experiment 15N natural abundance Ericoid mycorrhizas global change 14C pulse-labelling Carbon allocation |
description |
Some components of the below-ground carbon (C) cycle in terrestrial ecosystems are still poorly understood. A better understanding will be necessary to predict adequately the impacts of global change factors on C cycling and storage, especially in high-latitude ecosystems, where much of the C is stored below-ground. In this work some of the mechanisms of the below-ground C cycle in subarctic ecosystems were studied and responses to present and potential future environmental conditions assessed. Using 14C pulse-labelling, C allocation to above-ground biomass, rhizomes, coarse roots, fine roots, hair roots, ericoid mycorrhizas, microbes and dissolved organic C (DOC) was determined repeatedly over the growing season in four of the most common vegetation types of the Scandinavian subarctic: (1) Dry dwarf shrub tundra; (2) Semi-wet mire; (3) Wet mire; and (4) the understorey of subarctic birch forest. Effects of increased temperatures, increased atmospheric CO2 concentrations and both factors in combination on below-ground C allocation, ericoid mycorrhizal colonisation and functioning were studied in an full-factorial open-top chamber experiment. Furthermore, responses of ericoid mycorrhizal colonisation rates to environmental variation during the growing season were investigated. Ecosystem C partitioning varied temporally in all studied ecosystems, possibly indicating changes in growth, nutrient uptake or C storage by vegetation. The relative importance of C pools with "fast" versus "slow" turnover rates varied spatially, among vegetation types. Therefore it is important for global change studies to consider the possible effects of vegetation changes on ecosystem C dynamics. Allocation of recent assimilates to fast-turnover C pools such as hair roots and DOC was particularly high in a dwarf shrub tundra making them quantitatively interesting pools to consider in studies of ecosystem C dynamics. Furthermore, a significant proportion of assimilates in the DOC pool were allocated to P-mobilizing organic acids, ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Olsrud, Maria |
author_facet |
Olsrud, Maria |
author_sort |
Olsrud, Maria |
title |
Mechanisms of below-ground carbon cycling in subarctic ecosystems |
title_short |
Mechanisms of below-ground carbon cycling in subarctic ecosystems |
title_full |
Mechanisms of below-ground carbon cycling in subarctic ecosystems |
title_fullStr |
Mechanisms of below-ground carbon cycling in subarctic ecosystems |
title_full_unstemmed |
Mechanisms of below-ground carbon cycling in subarctic ecosystems |
title_sort |
mechanisms of below-ground carbon cycling in subarctic ecosystems |
publisher |
Maria Olsrud, CGB, Lund Sweden |
publishDate |
2004 |
url |
https://lup.lub.lu.se/record/467318 |
genre |
Subarctic Tundra |
genre_facet |
Subarctic Tundra |
op_relation |
https://lup.lub.lu.se/record/467318 urn:isbn:91-974997-0-6 scopus:5144228667 |
_version_ |
1766210411437228032 |