Abrupt rise in the contribution of CH₄-derived carbon to benthic secondary production of a shallow hemiboreal/boreal lake
Laen...
Kuupäev
2018
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Wiley
Abstrakt
Understanding long-term carbon flows through aquatic food webs is essential to assess impact of
climatic and environmental changes on lake ecosystems. We reconstructed temporal changes in carbon sources
fuelling chironomid biomass in a small and shallow hemiboreal/boreal lake over the last 11 000 years. Results
were compared with temporal dynamics of known potential controlling factors: summer air temperature, human
activities, phytoplankton assemblages and organic matter composition. We report an abrupt rise in the contribution
of methane-derived carbon to chironomid biomass. However, this sudden increase was not the consequence of
drastic changes in the composition of sedimentary organic matter, mean air temperature, lake trophic state or
human activities in the catchment area. Our results suggest that shallowing of the lake caused by sedimentary
infilling processes was a possible driver of the expansion of anoxic zones, enhancing CH 4 cycling in lake
sediments. However, complementary studies are needed to better understand the mechanisms by which lake
shallowing could affect carbon flows to aquatic consumers, and then better assess the natural dynamics of past
carbon processing in the benthic food web of shallow lakes.
Financial support was provided by institutional research grant IUT21-2, IUT1-8 from the Estonian Science Agency and by Estonian University of Life Sciences, project No. 8M160101PKLJ, and ‘Estophilus Grant’ from the Ministry of Culture of Estonia. We are grateful to Christian Hossann (INRA, Nancy, Champenoux) for assistance with the stable isotope analysis of carbon. The PTEF facility is supported by the French National Research Agency through the Laboratory of Excellence ARBRE (ANR-11-LABX-0002-01).
Financial support was provided by institutional research grant IUT21-2, IUT1-8 from the Estonian Science Agency and by Estonian University of Life Sciences, project No. 8M160101PKLJ, and ‘Estophilus Grant’ from the Ministry of Culture of Estonia. We are grateful to Christian Hossann (INRA, Nancy, Champenoux) for assistance with the stable isotope analysis of carbon. The PTEF facility is supported by the French National Research Agency through the Laboratory of Excellence ARBRE (ANR-11-LABX-0002-01).
Kirjeldus
Märksõnad
benthic food web, carbon stable isotope, Holocene, methane-derived carbon, subfossil chironomid, articles