Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study
Higher temperatures in northern latitudes will increase permafrost thaw and stimulate above- and belowground plant biomass growth in tundra ecosystems. Higher plant productivity increases the input of easily decomposable carbon (C) to soil, which can stimulate microbial activity and increase soil or...
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ftcdlib:oai:escholarship.org:ark:/13030/qt33h927kz 2023-07-02T03:33:25+02:00 Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study Pegoraro, Elaine Mauritz, Marguerite Bracho, Rosvel Ebert, Chris Dijkstra, Paul Hungate, Bruce A Konstantinidis, Konstantinos T Luo, Yiqi Schädel, Christina Tiedje, James M Zhou, Jizhong Schuur, Edward AG 2019-02-01 application/pdf https://escholarship.org/uc/item/33h927kz unknown eScholarship, University of California qt33h927kz https://escholarship.org/uc/item/33h927kz public Aging Priming Permafrost Carbon Radiocarbon Organic matter decomposition Environmental Sciences Biological Sciences Agricultural and Veterinary Sciences Agronomy & Agriculture article 2019 ftcdlib 2023-06-12T17:58:32Z Higher temperatures in northern latitudes will increase permafrost thaw and stimulate above- and belowground plant biomass growth in tundra ecosystems. Higher plant productivity increases the input of easily decomposable carbon (C) to soil, which can stimulate microbial activity and increase soil organic matter decomposition rates. This phenomenon, known as the priming effect, is particularly interesting in permafrost because an increase in C supply to deep, previously frozen soil may accelerate decomposition of C stored for hundreds to thousands of years. The sensitivity of old permafrost C to priming is not well known; most incubation studies last less than one year, and so focus on fast-cycling C pools. Furthermore, the age of respired soil C is rarely measured, even though old C may be vulnerable to labile C inputs. We incubated soil from a moist acidic tundra site in Eight Mile Lake, Alaska for 409 days at 15 °C. Soil from surface (0–25cm), transition (45–55cm), and permafrost (65–85cm) layers were amended with three pulses of uniformly ¹³C-labeled glucose or cellulose every 152 days. Glucose addition resulted in positive priming in the permafrost layer 7 days after each substrate addition, eliciting a two-fold increase in cumulative soil C loss relative to unamended soils with consistent effects across all three pulses. In the transition and permafrost layers, glucose addition significantly decreased the age of soil-respired CO₂-C with Δ¹⁴C values that were 115‰ higher. Previous field studies that measured the age of respired C in permafrost regions have attributed younger Δ¹⁴C ecosystem respiration values to higher plant contributions. However, the results from this study suggest that positive priming, due to an increase in fresh C supply to deeply thawed soil layers, can also explain the respiration of younger C observed at the ecosystem scale. We must consider priming effects to fully understand permafrost C dynamics, or we risk underestimating the contribution of soil C to ecosystem respiration. Article in Journal/Newspaper permafrost Tundra Alaska University of California: eScholarship |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Aging Priming Permafrost Carbon Radiocarbon Organic matter decomposition Environmental Sciences Biological Sciences Agricultural and Veterinary Sciences Agronomy & Agriculture |
spellingShingle |
Aging Priming Permafrost Carbon Radiocarbon Organic matter decomposition Environmental Sciences Biological Sciences Agricultural and Veterinary Sciences Agronomy & Agriculture Pegoraro, Elaine Mauritz, Marguerite Bracho, Rosvel Ebert, Chris Dijkstra, Paul Hungate, Bruce A Konstantinidis, Konstantinos T Luo, Yiqi Schädel, Christina Tiedje, James M Zhou, Jizhong Schuur, Edward AG Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
topic_facet |
Aging Priming Permafrost Carbon Radiocarbon Organic matter decomposition Environmental Sciences Biological Sciences Agricultural and Veterinary Sciences Agronomy & Agriculture |
description |
Higher temperatures in northern latitudes will increase permafrost thaw and stimulate above- and belowground plant biomass growth in tundra ecosystems. Higher plant productivity increases the input of easily decomposable carbon (C) to soil, which can stimulate microbial activity and increase soil organic matter decomposition rates. This phenomenon, known as the priming effect, is particularly interesting in permafrost because an increase in C supply to deep, previously frozen soil may accelerate decomposition of C stored for hundreds to thousands of years. The sensitivity of old permafrost C to priming is not well known; most incubation studies last less than one year, and so focus on fast-cycling C pools. Furthermore, the age of respired soil C is rarely measured, even though old C may be vulnerable to labile C inputs. We incubated soil from a moist acidic tundra site in Eight Mile Lake, Alaska for 409 days at 15 °C. Soil from surface (0–25cm), transition (45–55cm), and permafrost (65–85cm) layers were amended with three pulses of uniformly ¹³C-labeled glucose or cellulose every 152 days. Glucose addition resulted in positive priming in the permafrost layer 7 days after each substrate addition, eliciting a two-fold increase in cumulative soil C loss relative to unamended soils with consistent effects across all three pulses. In the transition and permafrost layers, glucose addition significantly decreased the age of soil-respired CO₂-C with Δ¹⁴C values that were 115‰ higher. Previous field studies that measured the age of respired C in permafrost regions have attributed younger Δ¹⁴C ecosystem respiration values to higher plant contributions. However, the results from this study suggest that positive priming, due to an increase in fresh C supply to deeply thawed soil layers, can also explain the respiration of younger C observed at the ecosystem scale. We must consider priming effects to fully understand permafrost C dynamics, or we risk underestimating the contribution of soil C to ecosystem respiration. |
format |
Article in Journal/Newspaper |
author |
Pegoraro, Elaine Mauritz, Marguerite Bracho, Rosvel Ebert, Chris Dijkstra, Paul Hungate, Bruce A Konstantinidis, Konstantinos T Luo, Yiqi Schädel, Christina Tiedje, James M Zhou, Jizhong Schuur, Edward AG |
author_facet |
Pegoraro, Elaine Mauritz, Marguerite Bracho, Rosvel Ebert, Chris Dijkstra, Paul Hungate, Bruce A Konstantinidis, Konstantinos T Luo, Yiqi Schädel, Christina Tiedje, James M Zhou, Jizhong Schuur, Edward AG |
author_sort |
Pegoraro, Elaine |
title |
Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
title_short |
Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
title_full |
Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
title_fullStr |
Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
title_full_unstemmed |
Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
title_sort |
glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study |
publisher |
eScholarship, University of California |
publishDate |
2019 |
url |
https://escholarship.org/uc/item/33h927kz |
genre |
permafrost Tundra Alaska |
genre_facet |
permafrost Tundra Alaska |
op_relation |
qt33h927kz https://escholarship.org/uc/item/33h927kz |
op_rights |
public |
_version_ |
1770273359316123648 |