Decadal warming causes a consistent and persistent shift from heterotrophic to autotrophic respiration in contrasting permafrost ecosystems

Soil carbon in permafrost ecosystems has the potential to become a major positive feedback to climate change if permafrost thaw increases heterotrophic decomposition. However, warming can also stimulate autotrophic production leading to increased ecosystem carbon storage—a negative climate change fe...

Celý popis

Uložené v:
Podrobná bibliografia
Vydané v:Global change biology Ročník 21; číslo 12; s. 4508 - 4519
Hlavní autori: Hicks Pries, Caitlin E., van Logtestijn, Richard S. P., Schuur, Edward A. G., Natali, Susan M., Cornelissen, Johannes H. C., Aerts, Rien, Dorrepaal, Ellen
Médium: Journal Article
Jazyk:English
Vydavateľské údaje: England Blackwell Science 01.12.2015
Blackwell Publishing Ltd
Predmet:
Air temperature
Alaska
Aquatic plants
Arctic Regions
autotrophic
Autotrophic Processes
carbon
Carbon Cycle
Carbon sequestration
Carbon sources
Climate Change
climate change feedback
Decomposition
ecosystem respiration
Ecosystems
Global Warming
Growing season
heterotrophic
Heterotrophic Processes
peatlands
Permafrost
permafrost thaw
Primary production
primary productivity
radiocarbon
Respiration
Seasons
Soil - chemistry
soil respiration
Soils
Sweden
Terrestrial ecosystems
Tundra
warming experiment
Wetlands
Alaska
Sweden
INE, USA, Alaska
carbon
ecosystem respiration
radiocarbon
heterotrophic
warming experiment
autotrophic
climate change feedback
permafrost thaw
ISSN:1354-1013, 1365-2486, 1365-2486
On-line prístup:Získať plný text
Tagy: Pridať tag
Žiadne tagy, Buďte prvý, kto otaguje tento záznam!
Popis
Shrnutí:Soil carbon in permafrost ecosystems has the potential to become a major positive feedback to climate change if permafrost thaw increases heterotrophic decomposition. However, warming can also stimulate autotrophic production leading to increased ecosystem carbon storage—a negative climate change feedback. Few studies partitioning ecosystem respiration examine decadal warming effects or compare responses among ecosystems. Here, we first examined how 11 years of warming during different seasons affected autotrophic and heterotrophic respiration in a bryophyte‐dominated peatland in Abisko, Sweden. We used natural abundance radiocarbon to partition ecosystem respiration into autotrophic respiration, associated with production, and heterotrophic decomposition. Summertime warming decreased the age of carbon respired by the ecosystem due to increased proportional contributions from autotrophic and young soil respiration and decreased proportional contributions from old soil. Summertime warming's large effect was due to not only warmer air temperatures during the growing season, but also to warmer deep soils year‐round. Second, we compared ecosystem respiration responses between two contrasting ecosystems, the Abisko peatland and a tussock‐dominated tundra in Healy, Alaska. Each ecosystem had two different timescales of warming (<5 years and over a decade). Despite the Abisko peatland having greater ecosystem respiration and larger contributions from heterotrophic respiration than the Healy tundra, both systems responded consistently to short‐ and long‐term warming with increased respiration, increased autotrophic contributions to ecosystem respiration, and increased ratios of autotrophic to heterotrophic respiration. We did not detect an increase in old soil carbon losses with warming at either site. If increased autotrophic respiration is balanced by increased primary production, as is the case in the Healy tundra, warming will not cause these ecosystems to become growing season carbon sources. Warming instead causes a persistent shift from heterotrophic to more autotrophic control of the growing season carbon cycle in these carbon‐rich permafrost ecosystems.
Bibliografia:http://dx.doi.org/10.1111/gcb.13032
University of Florida Graduate Research Abroad Program
ArticleID:GCB13032
Stiftelsen Oscar och Lili Lamms Minne
ark:/67375/WNG-HBBGP6NN-6
istex:812D99AA4E1773735E5944A28DFD79A7E9A1D12D
Knut and Alice Wallenberg Foundation
Table S1. The soil respiration flux (adjusted for the in situ soil temperatures) and the respired radiocarbon from individual core depth sections collected from the Abisko warming experiment. These values were used to calculate the depth-integrated radiocarbon values used in the SIAR model. Table S2. Soil moisture differences among treatments at Abisko and Healy. Fig. S1. The nonlinear relationship used to model ecosystem respiration at Abisko based on average daily soil temperature.Data S1. AbiskoHealyComparisonRcode.R: A file containing the R code for the statistical analyses presented in this paper.Data S2. AbiskoHealyComparisonData.xls: An excel file of datasheets containing the dataframes needed in the R code.
Doctoral Dissertation Improvement Grant
National Science Foundation
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
content type line 23
ISSN:1354-1013
1365-2486
1365-2486
DOI:10.1111/gcb.13032