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 A. G.

doi:10.1016/j.soilbio.2018.10.009

Cited by 33 publications

(34 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, changes in plant productivity and composition may alter the rates and contributions of R h to R eco through root exudates, litter quantity, and litter quality (Chapin et al, ). Addition of labile carbon and nitrogen (components of root exudates) usually enhances R h rates in organic soils where roots are abundant (Lavoie, Mack, & Schuur, ; Wild et al, ), and the effects can be more prominent in permafrost soils (Pegoraro et al, ). If drying decreases TD, as shown in this study, denser roots in shallow soil layers and more root exudates may enhance modern soil carbon decomposition, while reducing old soil carbon decomposition.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, changes in plant productivity and composition may alter the rates and contributions of R h to R eco through root exudates, litter quantity, and litter quality (Chapin et al, 2012). Addition of labile carbon and nitrogen (components of root exudates) usually enhances R h rates in organic soils where roots are abundant (Lavoie, Mack, & Schuur, 2011;Wild et al, 2016Wild et al, , 2014, and the effects can be more prominent in permafrost soils (Pegoraro et al, 2019 Fig. S2), implying that some proportion of R eco at Chersky may be linked to the release of CO 2 from deep soil layers through aerenchyma of E. angustifolium (Colmer, 2003).…”

Section: Effects Of Plant Changesmentioning

confidence: 99%

See 1 more Smart Citation

Drainage enhances modern soil carbon contribution but reduces old soil carbon contribution to ecosystem respiration in tundra ecosystems

Kwon

Natali

Pries

et al. 2019

Global Change Biology

View full text Add to dashboard Cite

Warming temperatures are likely to accelerate permafrost thaw in the Arctic, potentially leading to the release of old carbon previously stored in deep frozen soil layers. Deeper thaw depths in combination with geomorphological changes due to the loss of ice structures in permafrost, may modify soil water distribution, creating wetter or drier soil conditions. Previous studies revealed higher ecosystem respiration rates under drier conditions, and this study investigated the cause of the increased ecosystem respiration rates using radiocarbon signatures of respired CO2 from two drying manipulation experiments: one in moist and the other in wet tundra. We demonstrate that higher contributions of CO2 from shallow soil layers (0–15 cm; modern soil carbon) drive the increased ecosystem respiration rates, while contributions from deeper soil (below 15 cm from surface and down to the permafrost table; old soil carbon) decreased. These changes can be attributed to more aerobic conditions in shallow soil layers, but also the soil temperature increases in shallow layers but decreases in deep layers, due to the altered thermal properties of organic soils. Decreased abundance of aerenchymatous plant species following drainage in wet tundra reduced old carbon release but increased aboveground plant biomass elevated contributions of autotrophic respiration to ecosystem respiration. The results of this study suggest that drier soils following drainage may accelerate decomposition of modern soil carbon in shallow layers but slow down decomposition of old soil carbon in deep layers, which may offset some of the old soil carbon loss from thawing permafrost.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Furthermore, changes in plant productivity and composition may alter the rates and contributions of R h to R eco through root exudates, litter quantity, and litter quality (Chapin et al, 2012). Addition of labile carbon and nitrogen (components of root exudates) usually enhances R h rates in organic soils where roots are abundant (Lavoie, Mack, & Schuur, 2011;Wild et al, 2016Wild et al, , 2014, and the effects can be more prominent in permafrost soils (Pegoraro et al, 2019 Fig. S2), implying that some proportion of R eco at Chersky may be linked to the release of CO 2 from deep soil layers through aerenchyma of E. angustifolium (Colmer, 2003).…”

Section: Effects Of Plant Changesmentioning

confidence: 99%

Drainage enhances modern soil carbon contribution but reduces old soil carbon contribution to ecosystem respiration in tundra ecosystems

Kwon

Natali

Pries

et al. 2019

Global Change Biology

View full text Add to dashboard Cite

show abstract

“…As the vegetation continues to green and surface soil warms, the declining Recoδ 13 C trend most likely represents increasing root respiration (−25.5‰, Figure a) rather than surface SOC respiration (−23.5‰, Figure a) because No Veg also accounts for the negative isotopic signal from surface SOC decomposition. While the long‐term exclusion of plant inputs could reduce surface SOC respiration in No Veg, surface soil decomposition in permafrost soil is generally not C limited (Pegoraro et al, ; Salmon et al, ; Wild et al, ). Thus, the difference between No Veg, Shallow‐Dry, and Veg groups is more likely due to root respiration.…”

Section: Discussionmentioning

confidence: 99%

Using Stable Carbon Isotopes of Seasonal Ecosystem Respiration to Determine Permafrost Carbon Loss

et al. 2019

Self Cite

View full text Add to dashboard Cite

High latitude warming and permafrost thaw will expose vast stores of deep soil organic carbon (SOC) to decomposition. Thaw also changes water movement causing either wetter or drier soil. The fate of deep SOC under different thaw and moisture conditions is unclear. We measured weekly growing‐season δ13C of ecosystem respiration (Recoδ13C) across thaw and moisture conditions (Shallow‐Dry; Deep‐Dry; Deep‐Wet) in a soil warming manipulation. Deep SOC loss was inferred from known δ13C signatures of plant shoot, root, surface soil, and deep soil respiration. In addition, a 2‐year‐old vegetation removal treatment (No Veg) was used to isolate surface and deep SOC decomposition contributions to Reco. In No Veg, seasonal Recoδ13C indicated that deep SOC loss increased as the soil column thawed, while in vegetated areas, root contributions appeared to dominate Reco. The Recoδ13C differences between Shallow‐Dry and Deep‐Dry were significant but surprisingly small. This most likely suggests that, under dry conditions, soil warming stimulates root and surface SOC respiration with a negative 13C signature that opposes the more positive 13C signal from increased deep SOC respiration. In Deep‐Wet conditions, Recoδ13C suggests reduced deep SOC loss but could also reflect altered diffusion or methane (CH4) dynamics. Together, these results demonstrate that frequent Recoδ13C measurements can detect deep SOC loss and that plants confound the signal. In future studies, soil profile δ13C measurements, vegetation removal across thaw gradients, and isotopic effects of CH4 dynamics could further deconvolute deep SOC loss via surface Reco.

show abstract

“…Additionally, plant root exudates are known to be a source of C to soil and to determine rhizosphere microbial community composition (Tkacz et al, 2015). Microbial response to differences in C quality in root exudates (such as through shifts in activity or bacterial to fungal ratios) can influence decomposition dynamics such as by stimulating decomposition or causing additional C release from bulk peat through priming effects (Cheng et al, 2014;Pegoraro et al, 2019). Permafrost thaw has been shown to dramatically alter root growth patterns including quantity and quality of litter inputs which can be expected to influence microbial community composition (Blume-Werry et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient

et al. 2020

View full text Add to dashboard Cite

Plant-associated microbiomes are structured by environmental conditions and plant associates, both of which are being altered by climate change. The future structure of plant microbiomes will depend on the, largely unknown, relative importance of each. This uncertainty is particularly relevant for arctic peatlands, which are undergoing large shifts in plant communities and soil microbiomes as permafrost thaws, and are potentially appreciable sources of climate change feedbacks due to their soil carbon (C) storage. We characterized phyllosphere and rhizosphere microbiomes of six plant species, and bulk peat, across a permafrost thaw progression (from intact permafrost, to partiallyand fully-thawed stages) via 16S rRNA gene amplicon sequencing. We tested the hypothesis that the relative influence of biotic versus environmental filtering (the role of plant species versus thaw-defined habitat) in structuring microbial communities would differ among phyllosphere, rhizosphere, and bulk peat. Using both abundance-and phylogenetic-based approaches, we found that phyllosphere microbial composition was more strongly explained by plant associate, with little influence of habitat, whereas in the rhizosphere, plant and habitat had similar influence. Network-based community analyses showed that keystone taxa exhibited similar patterns with stronger responses to drivers. However, plant associates appeared to have a larger influence on organisms belonging to families associated with methane-cycling than the bulk community. Putative methanogens were more strongly influenced by plant than habitat in the rhizosphere, and in the phyllosphere putative methanotrophs were more strongly influenced by plant than was the community at large. We conclude that biotic effects can be stronger than environmental filtering, but their relative importance varies among microbial groups. For most microbes in this system, biotic filtering was stronger aboveground than belowground. However, for putative methane-cyclers, plant associations have a stronger influence on community composition than environment despite major hydrological changes with thaw. This suggests that plant successional dynamics may be as important as hydrological changes in determining microbial relevance to C-cycling

show abstract

Glucose addition increases the magnitude and decreases the age of soil respired carbon in a long-term permafrost incubation study

Cited by 33 publications

References 80 publications

Drainage enhances modern soil carbon contribution but reduces old soil carbon contribution to ecosystem respiration in tundra ecosystems

Drainage enhances modern soil carbon contribution but reduces old soil carbon contribution to ecosystem respiration in tundra ecosystems

Using Stable Carbon Isotopes of Seasonal Ecosystem Respiration to Determine Permafrost Carbon Loss

Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient

Contact Info

Product

Resources

About