You are here

Source, transport and fate of soil organic matter inferred from microbial biomarker lipids on the East Siberian Arctic Shelf

Title: Source, Transport And Fate Of Soil Organic Matter Inferred From Microbial Biomarker Lipids On The East Siberian Arctic Shelf.
5 views
0 downloads
Name(s): Bischoff, Juliane, author
Sparkes, Robert B., author
Selver, Ayca Dogrul, author
Spencer, Robert G. M., author
Gustafsson, Orjan, author
Semiletov, Igor P., author
Dudarev, Oleg V., author
Wagner, Dirk, author
Rivkina, Elizaveta, author
van Dongen, Bart E., author
Talbot, Helen M., author
Type of Resource: text
Genre: text
Date Issued: 2016-09-06
Physical Form: computer
Physical Form: online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: The Siberian Arctic contains a globally significant pool of organic carbon (OC) vulnerable to enhanced warming and subsequent release by both fluvial and coastal erosion processes. However, the rate of release, its behaviour in the Arctic Ocean and vulnerability to remineralisation is poorly understood. Here we combine new measurements of microbial biohopanoids including adenosylhopane, a lipid associated with soil microbial communities, with published glycerol dialkyl glycerol tetraethers (GDGTs) and bulk delta C-13 measurements to improve knowledge of the fate of OC transported to the East Siberian Arctic Shelf (ESAS). The microbial hopanoid-based soil OC proxy R'(soil) ranges from 0.0 to 0.8 across the ESAS, with highest values nearshore and decreases offshore. Across the shelf R'(soil) displays a negative linear correlation with bulk delta C-13 measurements (r(2) = -0.73, p = < 0 : 001). When compared to the GDGT-based OC proxy, the branched and isoprenoid tetraether (BIT) index, a decoupled (non-linear) behaviour on the shelf was observed, particularly in the Buor-Khaya Bay, where the R'(soil) shows limited variation, whereas the BIT index shows a rapid decline moving away from the Lena River outflow channels. This reflects a balance between delivery and removal of OC from different sources. The good correlation between the hopanoid and bulk terrestrial signal suggests a broad range of hopanoid sources, both fluvial and via coastal erosion, whilst GDGTs appear to be primarily sourced via fluvial transport. Analysis of ice complex deposits (ICDs) revealed an average R'(soil) of 0.5 for the Lena Delta, equivalent to that of the Buor-Khaya Bay sediments, whilst ICDs from further east showed higher values (0.6-0.85). Although R'(soil) correlates more closely with bulk OC than the BIT, our understanding of the endmembers of this system is clearly still incomplete, with variations between the different East Siberian Arctic regions potentially reflecting differences in environmental conditions (e.g. temperature, pH), but other physiological controls on microbial bacteriohopanepolyol (BHP) production under psychrophilic conditions are as yet unknown.
Identifier: FSU_libsubv1_wos_000383962600002 (IID), 10.5194/bg-13-4899-2016 (DOI)
Keywords: bacterial-populations, buor-khaya bay, dialkyl glycerol tetraethers, holocene sediments, old carbon, permafrost thaw, sedimentary bacteriohopanepolyols, suspended particulate matter, trap mass-spectrometry, yenisei river
Publication Note: The publisher’s version of record is available at https://doi.org/10.5194/bg-13-4899-2016
Owner Institution: FSU
Is Part Of: Biogeosciences.
1726-4170
Issue: iss. 17, vol. 13

Choose the citation style.
Bischoff, J., Sparkes, R. B., Selver, A. D., Spencer, R. G. M., Gustafsson, O., Semiletov, I. P., … Talbot, H. M. (2016). Source, Transport And Fate Of Soil Organic Matter Inferred From Microbial Biomarker Lipids On The East Siberian Arctic Shelf. Biogeosciences.