The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment
Warming may increase the extent and intensity of insect defoliations within Arctic ecosystems. A thorough understanding of the implications of this for litter decomposition is essential to make predictions of soil-atmosphere carbon (C) feedbacks. Soil nitrogen (N) and C cycles naturally are interlin...
Published in: | Biogeochemistry |
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Language: | English |
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Umeå universitet, Institutionen för ekologi, miljö och geovetenskap
2018
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149026 https://doi.org/10.1007/s10533-018-0448-8 |
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ftumeauniv:oai:DiVA.org:umu-149026 2023-10-09T21:49:27+02:00 The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment Kristensen, Jeppe A. Metcalfe, Daniel B. Rousk, Johannes 2018 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149026 https://doi.org/10.1007/s10533-018-0448-8 eng eng Umeå universitet, Institutionen för ekologi, miljö och geovetenskap Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden Biogeochemistry, 0168-2563, 2018, 138:3, s. 323-336 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149026 doi:10.1007/s10533-018-0448-8 ISI:000433339900006 Scopus 2-s2.0-85046488756 info:eu-repo/semantics/openAccess Subarctic birch forest soil respiration nitrogen mineralisation soil microbial ecology herbivory biogeochemistry Ecology Ekologi Article in journal info:eu-repo/semantics/article text 2018 ftumeauniv https://doi.org/10.1007/s10533-018-0448-8 2023-09-22T13:50:12Z Warming may increase the extent and intensity of insect defoliations within Arctic ecosystems. A thorough understanding of the implications of this for litter decomposition is essential to make predictions of soil-atmosphere carbon (C) feedbacks. Soil nitrogen (N) and C cycles naturally are interlinked, but we lack a detailed understanding of how insect herbivores impact these cycles. In a laboratory microcosm study, we investigated the growth responses of heterotrophic soil fungi and bacteria as well as C and N mineralisation to simulated defoliator outbreaks (frass addition), long-term increased insect herbivory (litter addition at higher background N-level) and non-outbreak conditions (litter addition only) in soils from a Subarctic birch forest. Larger amounts of the added organic matter were mineralised in the outbreak simulations compared to a normal year; yet, the fungal and bacterial growth rates and biomass were not significantly different. In the simulation of long-term increased herbivory, less litter C was respired per unit mineralised N (C:N of mineralisation decreased to 20 +/- 1 from 38 +/- 3 for pure litter), which suggests a directed microbial mining for N-rich substrates. This was accompanied by higher fungal dominance relative to bacteria and lower total microbial biomass. In conclusion, while a higher fraction of foliar C will be respired by insects and microbes during outbreak years, predicted long-term increases in herbivory linked to climate change may facilitate soil C-accumulation, as less foliar C is respired per unit mineralised N. Further work elucidating animal-plant-soil interactions is needed to improve model predictions of C-sink capacity in high latitude forest ecosystems. Correction: Kristensen, J.A., Metcalfe, D.B., Rousk, J. The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic: a microcosm simulation experiment. Biogeochemistry. 2018;138:337. https://doi.org/10.1007/s10533-018-0451-0 Article in Journal/Newspaper Arctic Climate change Subarctic Umeå University: Publications (DiVA) Arctic Kristensen ENVELOPE(-159.667,-159.667,-86.333,-86.333) Metcalfe ENVELOPE(-66.942,-66.942,-67.976,-67.976) Biogeochemistry 138 3 323 336 |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
Subarctic birch forest soil respiration nitrogen mineralisation soil microbial ecology herbivory biogeochemistry Ecology Ekologi |
spellingShingle |
Subarctic birch forest soil respiration nitrogen mineralisation soil microbial ecology herbivory biogeochemistry Ecology Ekologi Kristensen, Jeppe A. Metcalfe, Daniel B. Rousk, Johannes The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
topic_facet |
Subarctic birch forest soil respiration nitrogen mineralisation soil microbial ecology herbivory biogeochemistry Ecology Ekologi |
description |
Warming may increase the extent and intensity of insect defoliations within Arctic ecosystems. A thorough understanding of the implications of this for litter decomposition is essential to make predictions of soil-atmosphere carbon (C) feedbacks. Soil nitrogen (N) and C cycles naturally are interlinked, but we lack a detailed understanding of how insect herbivores impact these cycles. In a laboratory microcosm study, we investigated the growth responses of heterotrophic soil fungi and bacteria as well as C and N mineralisation to simulated defoliator outbreaks (frass addition), long-term increased insect herbivory (litter addition at higher background N-level) and non-outbreak conditions (litter addition only) in soils from a Subarctic birch forest. Larger amounts of the added organic matter were mineralised in the outbreak simulations compared to a normal year; yet, the fungal and bacterial growth rates and biomass were not significantly different. In the simulation of long-term increased herbivory, less litter C was respired per unit mineralised N (C:N of mineralisation decreased to 20 +/- 1 from 38 +/- 3 for pure litter), which suggests a directed microbial mining for N-rich substrates. This was accompanied by higher fungal dominance relative to bacteria and lower total microbial biomass. In conclusion, while a higher fraction of foliar C will be respired by insects and microbes during outbreak years, predicted long-term increases in herbivory linked to climate change may facilitate soil C-accumulation, as less foliar C is respired per unit mineralised N. Further work elucidating animal-plant-soil interactions is needed to improve model predictions of C-sink capacity in high latitude forest ecosystems. Correction: Kristensen, J.A., Metcalfe, D.B., Rousk, J. The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic: a microcosm simulation experiment. Biogeochemistry. 2018;138:337. https://doi.org/10.1007/s10533-018-0451-0 |
format |
Article in Journal/Newspaper |
author |
Kristensen, Jeppe A. Metcalfe, Daniel B. Rousk, Johannes |
author_facet |
Kristensen, Jeppe A. Metcalfe, Daniel B. Rousk, Johannes |
author_sort |
Kristensen, Jeppe A. |
title |
The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
title_short |
The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
title_full |
The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
title_fullStr |
The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
title_full_unstemmed |
The biogeochemical consequences of litter transformation by insect herbivory in the Subarctic : a microcosm simulation experiment |
title_sort |
biogeochemical consequences of litter transformation by insect herbivory in the subarctic : a microcosm simulation experiment |
publisher |
Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2018 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149026 https://doi.org/10.1007/s10533-018-0448-8 |
long_lat |
ENVELOPE(-159.667,-159.667,-86.333,-86.333) ENVELOPE(-66.942,-66.942,-67.976,-67.976) |
geographic |
Arctic Kristensen Metcalfe |
geographic_facet |
Arctic Kristensen Metcalfe |
genre |
Arctic Climate change Subarctic |
genre_facet |
Arctic Climate change Subarctic |
op_relation |
Biogeochemistry, 0168-2563, 2018, 138:3, s. 323-336 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149026 doi:10.1007/s10533-018-0448-8 ISI:000433339900006 Scopus 2-s2.0-85046488756 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/s10533-018-0448-8 |
container_title |
Biogeochemistry |
container_volume |
138 |
container_issue |
3 |
container_start_page |
323 |
op_container_end_page |
336 |
_version_ |
1779312470906634240 |