Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates
Abstract: Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to te...
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ftunivalberta:oai:era.library.ualberta.ca:49899081-bfe6-40ea-bc80-cd74c65e2274 2023-05-15T15:00:34+02:00 Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates Dimitrov, D. D. Grant, R. F. Lafleur, P. M. Humphreys, E. R. 2011 https://era.library.ualberta.ca/items/49899081-bfe6-40ea-bc80-cd74c65e2274 https://doi.org/10.7939/R3X921R5S English eng https://era.library.ualberta.ca/items/49899081-bfe6-40ea-bc80-cd74c65e2274 doi:10.7939/R3X921R5S © 2011 American Geophysical Union. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited. Water relations Model ecosys Plant biomass CO2 exchange Balance Carbon-dioxide exchange Nitrogen Enrichment face experiment Canada Forests Article (Published) 2011 ftunivalberta https://doi.org/10.7939/R3X921R5S 2022-08-22T20:10:34Z Abstract: Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to test hypotheses for these changes with CO(2) and energy fluxes measured by eddy covariance over a mesic shrub tundra at Daring Lake, Canada, under varying growing seasons. These tests corroborated substantial rises in NPP, smaller rises in Rh, and, hence, rises in net ecosystem productivity (NEP) from 17 to 45 g C m(-2) yr(-1) (net C sink), modeled with higher T(a) and longer growing seasons. However, NEP was found to decline briefly during midsummer warming events (T(a) > 20 degrees C). A model run under climate change predicted for Daring Lake indicated that rises in NPP would exceed those in Rh during the first 100 years, causing NEP to rise. Rises in NPP were driven by more rapid net N mineralization from more rapid Rh in warming soils. However, greater declines in NEP were modeled during more frequent and intense midsummer warming events as climate change progressed. Consequently, average annual NEP (+/- interannual variability) rose from 30 (+/- 13) g C m(-2) yr(-1) under current climate to 57 (+/- 40) g C m(-2) yr(-1) after 90 years but declined to 44 (+/- 51) g C m-2 yr(-1) after 150 years, indicating that gains in tundra NEP under climate change may not be indefinite. Other/Unknown Material Arctic Climate change Tundra University of Alberta: Era - Education and Research Archive Arctic Canada Daring Lake ENVELOPE(-111.635,-111.635,64.834,64.834) |
institution |
Open Polar |
collection |
University of Alberta: Era - Education and Research Archive |
op_collection_id |
ftunivalberta |
language |
English |
topic |
Water relations Model ecosys Plant biomass CO2 exchange Balance Carbon-dioxide exchange Nitrogen Enrichment face experiment Canada Forests |
spellingShingle |
Water relations Model ecosys Plant biomass CO2 exchange Balance Carbon-dioxide exchange Nitrogen Enrichment face experiment Canada Forests Dimitrov, D. D. Grant, R. F. Lafleur, P. M. Humphreys, E. R. Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
topic_facet |
Water relations Model ecosys Plant biomass CO2 exchange Balance Carbon-dioxide exchange Nitrogen Enrichment face experiment Canada Forests |
description |
Abstract: Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to test hypotheses for these changes with CO(2) and energy fluxes measured by eddy covariance over a mesic shrub tundra at Daring Lake, Canada, under varying growing seasons. These tests corroborated substantial rises in NPP, smaller rises in Rh, and, hence, rises in net ecosystem productivity (NEP) from 17 to 45 g C m(-2) yr(-1) (net C sink), modeled with higher T(a) and longer growing seasons. However, NEP was found to decline briefly during midsummer warming events (T(a) > 20 degrees C). A model run under climate change predicted for Daring Lake indicated that rises in NPP would exceed those in Rh during the first 100 years, causing NEP to rise. Rises in NPP were driven by more rapid net N mineralization from more rapid Rh in warming soils. However, greater declines in NEP were modeled during more frequent and intense midsummer warming events as climate change progressed. Consequently, average annual NEP (+/- interannual variability) rose from 30 (+/- 13) g C m(-2) yr(-1) under current climate to 57 (+/- 40) g C m(-2) yr(-1) after 90 years but declined to 44 (+/- 51) g C m-2 yr(-1) after 150 years, indicating that gains in tundra NEP under climate change may not be indefinite. |
format |
Other/Unknown Material |
author |
Dimitrov, D. D. Grant, R. F. Lafleur, P. M. Humphreys, E. R. |
author_facet |
Dimitrov, D. D. Grant, R. F. Lafleur, P. M. Humphreys, E. R. |
author_sort |
Dimitrov, D. D. |
title |
Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
title_short |
Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
title_full |
Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
title_fullStr |
Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
title_full_unstemmed |
Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
title_sort |
ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates |
publishDate |
2011 |
url |
https://era.library.ualberta.ca/items/49899081-bfe6-40ea-bc80-cd74c65e2274 https://doi.org/10.7939/R3X921R5S |
long_lat |
ENVELOPE(-111.635,-111.635,64.834,64.834) |
geographic |
Arctic Canada Daring Lake |
geographic_facet |
Arctic Canada Daring Lake |
genre |
Arctic Climate change Tundra |
genre_facet |
Arctic Climate change Tundra |
op_relation |
https://era.library.ualberta.ca/items/49899081-bfe6-40ea-bc80-cd74c65e2274 doi:10.7939/R3X921R5S |
op_rights |
© 2011 American Geophysical Union. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited. |
op_doi |
https://doi.org/10.7939/R3X921R5S |
_version_ |
1766332655039676416 |