Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics
Arctic tundra is a globally important store for carbon (C). However, there is a lack of reference sites characterising C exchange dynamics across annual cycles. Based on the Greenland Ecosystem Monitoring (GEM) programme, here we present 9–11 years of flux and ecosystem data across the period 2008–2...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/ab865b |
| _version_ | 1797747524883185664 |
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| author | Efrén López-Blanco Marcin Jackowicz-Korczynski Mikhail Mastepanov Kirstine Skov Andreas Westergaard-Nielsen Mathew Williams Torben R Christensen |
| author_facet | Efrén López-Blanco Marcin Jackowicz-Korczynski Mikhail Mastepanov Kirstine Skov Andreas Westergaard-Nielsen Mathew Williams Torben R Christensen |
| author_sort | Efrén López-Blanco |
| collection | DOAJ |
| description | Arctic tundra is a globally important store for carbon (C). However, there is a lack of reference sites characterising C exchange dynamics across annual cycles. Based on the Greenland Ecosystem Monitoring (GEM) programme, here we present 9–11 years of flux and ecosystem data across the period 2008–2018 from two wetland sites in Greenland: Zackenberg (74°N) and Kobbefjord (64°N). The Zackenberg fen was a strong C sink despite its higher latitude and shorter growing seasons compared to the Kobbefjord fen. On average the ecosystem in Zackenberg took up ∼−50 g C m ^−2 yr ^−1 (range of +21 to −90 g C m ^−2 yr ^−1 ), more than twice that of Kobbefjord (mean ∼−18 g C m ^−2 yr ^−1 , and range of +41 to − 41 g C m ^−2 yr ^−1 ). The larger net carbon sequestration in Zackenberg fen was associated with higher leaf nitrogen (71%), leaf area index (140%), and plant quality (i.e. C:N ratio; 36%). Additional evidence from in-situ measurements includes 3 times higher levels of dissolved organic carbon in soils and 5 times more available plant nutrients, including dissolved organic nitrogen (N) and nitrates, in Zackenberg. Simulations using the soil-plant-atmosphere ecosystem model showed that Zackenberg’s stronger CO _2 sink could be related to measured differences in plant nutrients, and their effects on photosynthesis and respiration. The model explained 69% of the variability of net ecosystem exchange of CO _2 , 80% for photosynthesis and 71% for respiration over 11 years at Zackenberg, similar to previous results at Kobbefjord (73%, 73%, and 50%, respectively, over 8 years). We conclude that growing season limitations of plant phenology on net C uptake have been more than counterbalanced by the increased leaf nutrient content at the Zackenberg site. |
| first_indexed | 2024-03-12T15:51:49Z |
| format | Article |
| id | doaj.art-61bc3c6386794149b8f92c934ce27728 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:51:49Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-61bc3c6386794149b8f92c934ce277282023-08-09T15:06:05ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115909400710.1088/1748-9326/ab865bMulti-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamicsEfrén López-Blanco0https://orcid.org/0000-0002-3796-8408Marcin Jackowicz-Korczynski1https://orcid.org/0000-0002-6574-5703Mikhail Mastepanov2https://orcid.org/0000-0002-5543-0302Kirstine Skov3https://orcid.org/0000-0003-1234-3687Andreas Westergaard-Nielsen4https://orcid.org/0000-0003-1021-0530Mathew Williams5https://orcid.org/0000-0001-6117-5208Torben R Christensen6https://orcid.org/0000-0002-4917-148XDepartment of Bioscience, Arctic Research Center, Aarhus University , Roskilde, DenmarkDepartment of Bioscience, Arctic Research Center, Aarhus University , Roskilde, Denmark; Department of Physical Geography and Ecosystem Science, Lund University , Lund, SwedenDepartment of Bioscience, Arctic Research Center, Aarhus University , Roskilde, Denmark; Oulanka Research Station, Oulu University , Kuusamo, FinlandDepartment of Bioscience, Arctic Research Center, Aarhus University , Roskilde, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen , Copenhagen, DenmarkCenter for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen , Copenhagen, DenmarkSchool of GeoSciences, University of Edinburgh , Edinburgh, United KingdomDepartment of Bioscience, Arctic Research Center, Aarhus University , Roskilde, DenmarkArctic tundra is a globally important store for carbon (C). However, there is a lack of reference sites characterising C exchange dynamics across annual cycles. Based on the Greenland Ecosystem Monitoring (GEM) programme, here we present 9–11 years of flux and ecosystem data across the period 2008–2018 from two wetland sites in Greenland: Zackenberg (74°N) and Kobbefjord (64°N). The Zackenberg fen was a strong C sink despite its higher latitude and shorter growing seasons compared to the Kobbefjord fen. On average the ecosystem in Zackenberg took up ∼−50 g C m ^−2 yr ^−1 (range of +21 to −90 g C m ^−2 yr ^−1 ), more than twice that of Kobbefjord (mean ∼−18 g C m ^−2 yr ^−1 , and range of +41 to − 41 g C m ^−2 yr ^−1 ). The larger net carbon sequestration in Zackenberg fen was associated with higher leaf nitrogen (71%), leaf area index (140%), and plant quality (i.e. C:N ratio; 36%). Additional evidence from in-situ measurements includes 3 times higher levels of dissolved organic carbon in soils and 5 times more available plant nutrients, including dissolved organic nitrogen (N) and nitrates, in Zackenberg. Simulations using the soil-plant-atmosphere ecosystem model showed that Zackenberg’s stronger CO _2 sink could be related to measured differences in plant nutrients, and their effects on photosynthesis and respiration. The model explained 69% of the variability of net ecosystem exchange of CO _2 , 80% for photosynthesis and 71% for respiration over 11 years at Zackenberg, similar to previous results at Kobbefjord (73%, 73%, and 50%, respectively, over 8 years). We conclude that growing season limitations of plant phenology on net C uptake have been more than counterbalanced by the increased leaf nutrient content at the Zackenberg site.https://doi.org/10.1088/1748-9326/ab865barctic tundraGreenlandnet ecosystem exchangephotosynthesisecosystem respirationnutrient availability |
| spellingShingle | Efrén López-Blanco Marcin Jackowicz-Korczynski Mikhail Mastepanov Kirstine Skov Andreas Westergaard-Nielsen Mathew Williams Torben R Christensen Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics Environmental Research Letters arctic tundra Greenland net ecosystem exchange photosynthesis ecosystem respiration nutrient availability |
| title | Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics |
| title_full | Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics |
| title_fullStr | Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics |
| title_full_unstemmed | Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics |
| title_short | Multi-year data-model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem C dynamics |
| title_sort | multi year data model evaluation reveals the importance of nutrient availability over climate in arctic ecosystem c dynamics |
| topic | arctic tundra Greenland net ecosystem exchange photosynthesis ecosystem respiration nutrient availability |
| url | https://doi.org/10.1088/1748-9326/ab865b |
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