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Evidence for past variations in methane availability in a Siberian thermokarst lake based on delta C-13 of chitinous invertebrate remains

van Hardenbroek, M.; Heiri, O.; Parmentier, Frans-Jan LU ; Bastviken, D.; Ilyashuk, B. P.; Wiklund, J. A.; Hall, R. I. and Lotter, A. F. (2013) In Quaternary Science Reviews 66. p.74-84
Abstract
Understanding past methane dynamics in arctic wetlands and lakes is crucial for estimating future methane release. Methane fluxes from lake ecosystems have increasingly been studied, yet only few reconstructions of past methane emissions from lakes are available. In this study, we develop an approach to assess changes in methane availability in lakes based on delta C-13 of chitinous invertebrate remains and apply this to a sediment record from a Siberian thermokarst lake. Diffusive methane fluxes from the surface of ten newly sampled Siberian lakes and seven previously studied Swedish lakes were compared to taxon-specific delta C-13 values of invertebrate remains from lake surface sediments to investigate whether these invertebrates... (More)
Understanding past methane dynamics in arctic wetlands and lakes is crucial for estimating future methane release. Methane fluxes from lake ecosystems have increasingly been studied, yet only few reconstructions of past methane emissions from lakes are available. In this study, we develop an approach to assess changes in methane availability in lakes based on delta C-13 of chitinous invertebrate remains and apply this to a sediment record from a Siberian thermokarst lake. Diffusive methane fluxes from the surface of ten newly sampled Siberian lakes and seven previously studied Swedish lakes were compared to taxon-specific delta C-13 values of invertebrate remains from lake surface sediments to investigate whether these invertebrates assimilated C-13-depleted carbon typical for methane. Remains of chironomid larvae of the tribe Orthocladiinae that, in the study lakes, mainly assimilate plant-derived carbon had higher delta C-13 than other invertebrate groups. delta C-13 of other invertebrates such as several chironomid groups (Chironomus, Chironomini, Tanytarsini, and Tanypodinae), cladocerans (Daphnia), and ostracods were generally lower. delta C-13 of Chironomini and Daphnia, and to a lesser extent Tanytarsini was variable in the lakes and lower at sites with higher diffusive methane fluxes. delta C-13 of Chironomini, Tanytarsini, and Daphnia were correlated significantly with diffusive methane flux in the combined Siberian and Swedish dataset (r = -0.72, p = 0.001, r = -0.53, p = 0.03, and r = -0.81, p < 0.001, respectively), suggesting that delta C-13 in these invertebrates was affected by methane availability. In a second step, we measured delta C-13 of invertebrate remains from a sediment record of Lake S1, a shallow thermokarst lake in northeast Siberia. In this record, covering the past ca 1000 years, delta C-13 of taxa most sensitive to methane availability (Chironomini, Tanytarsini, and Daphnia) was lowest in sediments deposited from ca AD 1250 to ca AD 1500, and after AD 1970, coinciding with warmer climate as indicated by an independent local temperature record. As a consequence the offset in delta C-13 between methane-sensitive taxa and bulk organic matter was higher in these sections than in other parts of the core. In contrast, delta C-13 of other invertebrate taxa did not show this trend. Our results suggest higher methane availability in the study lake during warmer periods and that thermokarst lakes can respond dynamically in their methane output to changing environmental conditions. (C) 2012 Elsevier Ltd. All rights reserved. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
keywords
Methane, Invertebrates, Chitinous remains, Lake sediment, Stable carbon, isotopes, Chironomids
in
Quaternary Science Reviews
volume
66
pages
74 - 84
publisher
Elsevier
external identifiers
  • wos:000317448500008
  • scopus:84881372403
ISSN
0277-3791
DOI
10.1016/j.quascirev.2012.04.009
language
English
LU publication?
yes
id
f05dd0a8-050d-4694-bfaf-46e5997f1af8 (old id 3739119)
date added to LUP
2013-05-22 12:33:31
date last changed
2019-08-28 01:39:35
@article{f05dd0a8-050d-4694-bfaf-46e5997f1af8,
  abstract     = {Understanding past methane dynamics in arctic wetlands and lakes is crucial for estimating future methane release. Methane fluxes from lake ecosystems have increasingly been studied, yet only few reconstructions of past methane emissions from lakes are available. In this study, we develop an approach to assess changes in methane availability in lakes based on delta C-13 of chitinous invertebrate remains and apply this to a sediment record from a Siberian thermokarst lake. Diffusive methane fluxes from the surface of ten newly sampled Siberian lakes and seven previously studied Swedish lakes were compared to taxon-specific delta C-13 values of invertebrate remains from lake surface sediments to investigate whether these invertebrates assimilated C-13-depleted carbon typical for methane. Remains of chironomid larvae of the tribe Orthocladiinae that, in the study lakes, mainly assimilate plant-derived carbon had higher delta C-13 than other invertebrate groups. delta C-13 of other invertebrates such as several chironomid groups (Chironomus, Chironomini, Tanytarsini, and Tanypodinae), cladocerans (Daphnia), and ostracods were generally lower. delta C-13 of Chironomini and Daphnia, and to a lesser extent Tanytarsini was variable in the lakes and lower at sites with higher diffusive methane fluxes. delta C-13 of Chironomini, Tanytarsini, and Daphnia were correlated significantly with diffusive methane flux in the combined Siberian and Swedish dataset (r = -0.72, p = 0.001, r = -0.53, p = 0.03, and r = -0.81, p &lt; 0.001, respectively), suggesting that delta C-13 in these invertebrates was affected by methane availability. In a second step, we measured delta C-13 of invertebrate remains from a sediment record of Lake S1, a shallow thermokarst lake in northeast Siberia. In this record, covering the past ca 1000 years, delta C-13 of taxa most sensitive to methane availability (Chironomini, Tanytarsini, and Daphnia) was lowest in sediments deposited from ca AD 1250 to ca AD 1500, and after AD 1970, coinciding with warmer climate as indicated by an independent local temperature record. As a consequence the offset in delta C-13 between methane-sensitive taxa and bulk organic matter was higher in these sections than in other parts of the core. In contrast, delta C-13 of other invertebrate taxa did not show this trend. Our results suggest higher methane availability in the study lake during warmer periods and that thermokarst lakes can respond dynamically in their methane output to changing environmental conditions. (C) 2012 Elsevier Ltd. All rights reserved.},
  author       = {van Hardenbroek, M. and Heiri, O. and Parmentier, Frans-Jan and Bastviken, D. and Ilyashuk, B. P. and Wiklund, J. A. and Hall, R. I. and Lotter, A. F.},
  issn         = {0277-3791},
  keyword      = {Methane,Invertebrates,Chitinous remains,Lake sediment,Stable carbon,isotopes,Chironomids},
  language     = {eng},
  pages        = {74--84},
  publisher    = {Elsevier},
  series       = {Quaternary Science Reviews},
  title        = {Evidence for past variations in methane availability in a Siberian thermokarst lake based on delta C-13 of chitinous invertebrate remains},
  url          = {http://dx.doi.org/10.1016/j.quascirev.2012.04.009},
  volume       = {66},
  year         = {2013},
}