The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils
Anthropogenic activities have globally increased nitrogen (N) deposition and carbon dioxide (CO₂) gas emissions. It is proposed that anthropogenic N deposition may increase the size of boreal forest CO₂ sink, because boreal ecosystems are N limited. Despite studies that have helped to clarify the ma...
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ftslunivuppsala:oai:pub.epsilon.slu.se:13700 2023-05-15T17:45:05+02:00 The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils Maaroufi, Nadia 2016-09-30 application/pdf https://pub.epsilon.slu.se/13700/ https://pub.epsilon.slu.se/13700/1/maaroufi_n_160930.pdf en eng eng https://pub.epsilon.slu.se/13700/1/maaroufi_n_160930.pdf Maaroufi, Nadia (2016). The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 2016:98 ISBN 978-91-576-8698-5 eISBN 978-91-576-8699-2 [Doctoral thesis] Ecology Forest Science Soil Science Doctoral thesis NonPeerReviewed info:eu-repo/semantics/doctoralThesis 2016 ftslunivuppsala 2022-07-28T16:13:49Z Anthropogenic activities have globally increased nitrogen (N) deposition and carbon dioxide (CO₂) gas emissions. It is proposed that anthropogenic N deposition may increase the size of boreal forest CO₂ sink, because boreal ecosystems are N limited. Despite studies that have helped to clarify the magnitude by which N deposition enhances carbon (C) sequestration in the vegetation, there remains a paucity of studies evaluating how soils respond. This thesis aims to clarify the magnitude to which C sequestration in boreal forests responds to N enrichments, including rates that realistically simulated N deposition (≤ 12.5 kg N ha⁻¹ yr⁻¹). This work was conducted in two long-term experiments in northern Sweden. The N treatments consisted of ambient, low N addition (3-12.5 kg N ha⁻¹ yr⁻¹) and high N addition (50 kg N ha⁻¹ yr⁻¹) rates, in a Norway spruce and a Scots pine forest, maintained since 1996 and 2004, respectively. The organic soil C pool positively responded to N enrichment, especially at the high N addition level. This increase corresponded to a relationship between C sequestration and N addition of 10 kg C kg⁻¹ N. Further, low N addition treatments had no effect on microbial biomass and soil respiration (i.e. soil C outputs, microbial activity), while high N addition decreased total microbial, ectomycorrhizal fungal biomasses and soil respiration. The actinomycetes were the only microbes showing an increase with N addition. Annual litter production showed a minor impact on aboveground litter C inputs. Only mosses were the only major litter component showing significant quantitative and qualitative changes in response to N additions. Further, litter quality mediated by N enrichment was not the main driver of litter decomposition, while shifts in soil microbes strongly influence the early stages of litter decomposition. Low N addition rates had little effect on litter and humus decomposition, whereas high N addition rates impeded the early stage of decomposition of both substrates. The decline of litter ... Doctoral or Postdoctoral Thesis Northern Sweden Swedish University of Agricultural Sciences (SLU): Epsilon Open Archive Norway |
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Open Polar |
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Swedish University of Agricultural Sciences (SLU): Epsilon Open Archive |
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ftslunivuppsala |
language |
English |
topic |
Ecology Forest Science Soil Science |
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Ecology Forest Science Soil Science Maaroufi, Nadia The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
topic_facet |
Ecology Forest Science Soil Science |
description |
Anthropogenic activities have globally increased nitrogen (N) deposition and carbon dioxide (CO₂) gas emissions. It is proposed that anthropogenic N deposition may increase the size of boreal forest CO₂ sink, because boreal ecosystems are N limited. Despite studies that have helped to clarify the magnitude by which N deposition enhances carbon (C) sequestration in the vegetation, there remains a paucity of studies evaluating how soils respond. This thesis aims to clarify the magnitude to which C sequestration in boreal forests responds to N enrichments, including rates that realistically simulated N deposition (≤ 12.5 kg N ha⁻¹ yr⁻¹). This work was conducted in two long-term experiments in northern Sweden. The N treatments consisted of ambient, low N addition (3-12.5 kg N ha⁻¹ yr⁻¹) and high N addition (50 kg N ha⁻¹ yr⁻¹) rates, in a Norway spruce and a Scots pine forest, maintained since 1996 and 2004, respectively. The organic soil C pool positively responded to N enrichment, especially at the high N addition level. This increase corresponded to a relationship between C sequestration and N addition of 10 kg C kg⁻¹ N. Further, low N addition treatments had no effect on microbial biomass and soil respiration (i.e. soil C outputs, microbial activity), while high N addition decreased total microbial, ectomycorrhizal fungal biomasses and soil respiration. The actinomycetes were the only microbes showing an increase with N addition. Annual litter production showed a minor impact on aboveground litter C inputs. Only mosses were the only major litter component showing significant quantitative and qualitative changes in response to N additions. Further, litter quality mediated by N enrichment was not the main driver of litter decomposition, while shifts in soil microbes strongly influence the early stages of litter decomposition. Low N addition rates had little effect on litter and humus decomposition, whereas high N addition rates impeded the early stage of decomposition of both substrates. The decline of litter ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Maaroufi, Nadia |
author_facet |
Maaroufi, Nadia |
author_sort |
Maaroufi, Nadia |
title |
The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
title_short |
The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
title_full |
The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
title_fullStr |
The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
title_full_unstemmed |
The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
title_sort |
effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils |
publishDate |
2016 |
url |
https://pub.epsilon.slu.se/13700/ https://pub.epsilon.slu.se/13700/1/maaroufi_n_160930.pdf |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_relation |
https://pub.epsilon.slu.se/13700/1/maaroufi_n_160930.pdf Maaroufi, Nadia (2016). The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 2016:98 ISBN 978-91-576-8698-5 eISBN 978-91-576-8699-2 [Doctoral thesis] |
_version_ |
1766147832707809280 |