Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing
The following article, Bokhorst, S., Berg, M.P., Edvinsen, G.K., Ellers, J., Heitman, A., Jaakola, L., . Bjerke, J.W. (2018). Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing. Frontiers in Plant Sci...
Published in: | Frontiers in Plant Science |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers Media
2018
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Subjects: | |
Online Access: | https://hdl.handle.net/10037/14915 https://doi.org/10.3389/fpls.2018.01787 |
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ftunivtroemsoe:oai:munin.uit.no:10037/14915 |
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openpolar |
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Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 cryptogam CO2 fluxes fatty acids frost geometrid moth herbivory multiple stress snow |
spellingShingle |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 cryptogam CO2 fluxes fatty acids frost geometrid moth herbivory multiple stress snow Bokhorst, Stef Berg, Matty P. Edvinsen, Guro Kristine Ellers, Jacintha Heitman, Amber Jaakola, Laura Mæhre, Hanne K Phoenix, Gareth K. Tømmervik, Hans Bjerke, Jarle W. Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
topic_facet |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 cryptogam CO2 fluxes fatty acids frost geometrid moth herbivory multiple stress snow |
description |
The following article, Bokhorst, S., Berg, M.P., Edvinsen, G.K., Ellers, J., Heitman, A., Jaakola, L., . Bjerke, J.W. (2018). Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing. Frontiers in Plant Science, 9 , can be accessed at https://doi.org/10.3389/fpls.2018.01787 . Climate change is one of many ongoing human-induced environmental changes, but few studies consider interactive effects between multiple anthropogenic disturbances. In coastal sub-arctic heathland, we quantified the impact of a factorial design simulating extreme winter warming (WW) events (7 days at 6–7∘C) combined with episodic summer nitrogen (+N) depositions (5 kg N ha-1) on plant winter physiology, plant community composition and ecosystem CO2 fluxes of an Empetrum nigrum dominated heathland during 3 consecutive years in northern Norway. We expected that the +N would exacerbate any stress effects caused by the WW treatment. During WW events, ecosystem respiration doubled, leaf respiration declined (-58%), efficiency of Photosystem II (Fv/Fm) increased (between 26 and 88%), while cell membrane fatty acids showed strong compositional changes as a result of the warming and freezing. In particular, longer fatty acid chains increased as a result of WW events, and eicosadienoic acid (C20:2) was lower when plants were exposed to the combination of WW and +N. A larval outbreak of geometrid moths ( Epirrita autumnata and Operophtera brumata ) following the first WW led to a near-complete leaf defoliation of the dominant dwarf shrubs E. nigrum (-87%) and Vaccinium myrtillus (-81%) across all experimental plots. Leaf emergence timing, plant biomass or composition, NDVI and growing season ecosystem CO2 fluxes were unresponsive to the WW and +N treatments. The limited plant community response reflected the relative mild winter freezing temperatures (-6.6∘C to -11.8∘C) recorded after the WW events, and that the grazing pressure probably overshadowed any potential treatment effects. The grazing pressure and WW both induce damage to the evergreen shrubs and their combination should therefore be even stronger. In addition, +N could have exacerbated the impact of both extreme events, but the ecosystem responses did not support this. Therefore, our results indicate that these sub-arctic Empetrum -dominated ecosystems are highly resilient and that their responses may be limited to the event with the strongest impact. |
format |
Article in Journal/Newspaper |
author |
Bokhorst, Stef Berg, Matty P. Edvinsen, Guro Kristine Ellers, Jacintha Heitman, Amber Jaakola, Laura Mæhre, Hanne K Phoenix, Gareth K. Tømmervik, Hans Bjerke, Jarle W. |
author_facet |
Bokhorst, Stef Berg, Matty P. Edvinsen, Guro Kristine Ellers, Jacintha Heitman, Amber Jaakola, Laura Mæhre, Hanne K Phoenix, Gareth K. Tømmervik, Hans Bjerke, Jarle W. |
author_sort |
Bokhorst, Stef |
title |
Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
title_short |
Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
title_full |
Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
title_fullStr |
Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
title_full_unstemmed |
Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing |
title_sort |
impact of multiple ecological stressors on a sub-arctic ecosystem: no interaction between extreme winter warming events, nitrogen addition and grazing |
publisher |
Frontiers Media |
publishDate |
2018 |
url |
https://hdl.handle.net/10037/14915 https://doi.org/10.3389/fpls.2018.01787 |
geographic |
Arctic Norway |
geographic_facet |
Arctic Norway |
genre |
Arctic Arctic Climate change Empetrum nigrum Northern Norway |
genre_facet |
Arctic Arctic Climate change Empetrum nigrum Northern Norway |
op_relation |
Frontiers in Plant Science info:eu-repo/grantAgreement/RCN/KLIMAFORSK/225006/Norway/Winter disturbance and nitrogen deposition: Unraveling the mechanisms behind ecosystem response to combined effects of climate and pollution// http://hdl.handle.net/11250/2576027 Bokhorst, S., Berg, M.P., Edvinsen, G.K., Ellers, J., Heitman, A., Jaakola, L., . Bjerke, J.W. (2018). Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing. Frontiers in Plant Science, 9 . https://doi.org/10.3389/fpls.2018.01787 FRIDAID 1639036 doi:10.3389/fpls.2018.01787 1664-462X https://hdl.handle.net/10037/14915 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.3389/fpls.2018.01787 |
container_title |
Frontiers in Plant Science |
container_volume |
9 |
_version_ |
1766301652644528128 |
spelling |
ftunivtroemsoe:oai:munin.uit.no:10037/14915 2023-05-15T14:27:45+02:00 Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing Bokhorst, Stef Berg, Matty P. Edvinsen, Guro Kristine Ellers, Jacintha Heitman, Amber Jaakola, Laura Mæhre, Hanne K Phoenix, Gareth K. Tømmervik, Hans Bjerke, Jarle W. 2018-11-30 https://hdl.handle.net/10037/14915 https://doi.org/10.3389/fpls.2018.01787 eng eng Frontiers Media Frontiers in Plant Science info:eu-repo/grantAgreement/RCN/KLIMAFORSK/225006/Norway/Winter disturbance and nitrogen deposition: Unraveling the mechanisms behind ecosystem response to combined effects of climate and pollution// http://hdl.handle.net/11250/2576027 Bokhorst, S., Berg, M.P., Edvinsen, G.K., Ellers, J., Heitman, A., Jaakola, L., . Bjerke, J.W. (2018). Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing. Frontiers in Plant Science, 9 . https://doi.org/10.3389/fpls.2018.01787 FRIDAID 1639036 doi:10.3389/fpls.2018.01787 1664-462X https://hdl.handle.net/10037/14915 openAccess VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 cryptogam CO2 fluxes fatty acids frost geometrid moth herbivory multiple stress snow Journal article Tidsskriftartikkel Peer reviewed 2018 ftunivtroemsoe https://doi.org/10.3389/fpls.2018.01787 2021-06-25T17:56:28Z The following article, Bokhorst, S., Berg, M.P., Edvinsen, G.K., Ellers, J., Heitman, A., Jaakola, L., . Bjerke, J.W. (2018). Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing. Frontiers in Plant Science, 9 , can be accessed at https://doi.org/10.3389/fpls.2018.01787 . Climate change is one of many ongoing human-induced environmental changes, but few studies consider interactive effects between multiple anthropogenic disturbances. In coastal sub-arctic heathland, we quantified the impact of a factorial design simulating extreme winter warming (WW) events (7 days at 6–7∘C) combined with episodic summer nitrogen (+N) depositions (5 kg N ha-1) on plant winter physiology, plant community composition and ecosystem CO2 fluxes of an Empetrum nigrum dominated heathland during 3 consecutive years in northern Norway. We expected that the +N would exacerbate any stress effects caused by the WW treatment. During WW events, ecosystem respiration doubled, leaf respiration declined (-58%), efficiency of Photosystem II (Fv/Fm) increased (between 26 and 88%), while cell membrane fatty acids showed strong compositional changes as a result of the warming and freezing. In particular, longer fatty acid chains increased as a result of WW events, and eicosadienoic acid (C20:2) was lower when plants were exposed to the combination of WW and +N. A larval outbreak of geometrid moths ( Epirrita autumnata and Operophtera brumata ) following the first WW led to a near-complete leaf defoliation of the dominant dwarf shrubs E. nigrum (-87%) and Vaccinium myrtillus (-81%) across all experimental plots. Leaf emergence timing, plant biomass or composition, NDVI and growing season ecosystem CO2 fluxes were unresponsive to the WW and +N treatments. The limited plant community response reflected the relative mild winter freezing temperatures (-6.6∘C to -11.8∘C) recorded after the WW events, and that the grazing pressure probably overshadowed any potential treatment effects. The grazing pressure and WW both induce damage to the evergreen shrubs and their combination should therefore be even stronger. In addition, +N could have exacerbated the impact of both extreme events, but the ecosystem responses did not support this. Therefore, our results indicate that these sub-arctic Empetrum -dominated ecosystems are highly resilient and that their responses may be limited to the event with the strongest impact. Article in Journal/Newspaper Arctic Arctic Climate change Empetrum nigrum Northern Norway University of Tromsø: Munin Open Research Archive Arctic Norway Frontiers in Plant Science 9 |