Global Biogeochemical Cycles
Supporting Information for
Multi-molecular tracers of terrestrial carbon transfer across the pan-Arctic: II. 14C
characteristics of sedimentary carbon components and their environmental controls
Xiaojuan Feng1,2, Örjan Gustafsson3, R. Max Holmes4, Jorien E. Vonk5,6, Bart E. van Dongen7, Igor P.
Semiletov8,9,10, Oleg V. Dudarev9,10, Mark B. Yunker11, Robie W. Macdonald12, Lukas Wacker13,
Daniel B. Montluçon2,14, and Timothy I. Eglinton2,14
1State
Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing,
China, 2Geological Institute, ETH Zürich, Zürich, Switzerland, 3Department of Environmental Science and Analytical
Chemistry (ACES) and the Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden, 4Woods Hole
Research Center, Falmouth, MA, USA, 5Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands, 6Arctic
Centre, University of Groningen, Groningen, The Netherlands, 7School of Earth, Atmospheric and Environmental Sciences
(SEAES) and the Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester,
UK, 8International Arctic Research Center (IARC), University of Alaska Fairbanks, Fairbanks, USA, 9Pacific Oceanological
Inst., Russian Academy of Sciences, Far Eastern Branch (FEBRAS), Vladivostok, Russia, 10National Tomsk Research
Polytechnic University, Tomsk, Russia, 117137 Wallace Dr., Brentwood Bay, BC, Canada, 12Department of Fisheries and
Oceans, Institute of Ocean Sciences, Sidney, BC, Canada, 13Laboratory of Ion Beam Physics (LIP), ETH Zürich, Zürich,
Switzerland, 14Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole,
MA, USA
Contents of this file
Text S1
Figures S1 to S2
Table S2
Additional Supporting Information (Files uploaded separately)
Caption for Tables S1
Introduction
This supporting information provides extended description of study area, schemes of biomarker
extraction and purification used in this study, logarithmic correlations between the abundanceweighted average ∆14C values of terrestrial lipids and total permafrost coverage, all the molecular ∆14C
values of individual lipid and phenol compounds in the arctic sediments, and comparison of ∆14C
values of the same sample measured at two AMS facilities.
Text S1. Extended description of study area.
The three eastern GRARs (Lena, Indigirka and Kolyma) drain into the Laptev Sea (Lena) and the East
Siberian Sea (Indigirka and Kolyma), with a cold and semiarid climate in their drainage basins and an
1
extensive coverage (79-100%) of continuous permafrost. This contrasts with the two western GRARs
(Ob’ and Yenisey) draining the west Siberian lowland into the Kara Sea, and the Kalix River that
flows through sub-arctic Scandinavia into the Baltic Sea, which are all characterized by wetter
climates, milder winters, and a much lower coverage of continuous permafrost (2-33%; Table 1). The
GRAR drainage basins are characterized by various tundra and wetlands in the north and by forests in
the south [FAO, 2001; van Dongen et al., 2008a]. The Kalix watershed mainly consists of forests
(60%) and wetland (20%) [Hjort, 1971]. A more detailed description of the Eurasian arctic drainage
basins is provided elsewhere [van Dongen et al., 2008a; Vonk et al., 2010; Holmes et al., 2013].
The drainage basin of Mackenzie River spans the western alpine region of the Cordillera Mountains to
the Canadian Shield and includes forests, swamps, grasslands, and permafrost soils. Previous studies
have established that petrogenic OC, mainly supplied by thermally immature bitumen, shales, or coals
from the Devonian Canol formation, is actively cycling through the Mackenzie system [Yunker et al.,
2002; Goñi et al., 2005; Drenzek et al., 2007]. The Yukon River drains northwestern Canada and
central Alaska in the United States into the Bering Sea. Its drainage basin is characterized by diverse
ecosystems including forests, shrublands, tundra, and extensive areas of permafrost [Brabets et al.,
2000]. The Colville River, originating in the Brooks Range in northern Alaska, is much smaller than
the Yukon and Mackenzie in terms of watershed area (Table 1), but is the largest North American
river (both in terms of freshwater and sediment load) that exclusively drains continuous permafrost
[Walker, 1998]. The Colville flows from the foothills of the Brooks Range and across the adjacent
arctic coastal plain to the Beaufort Sea. Its watershed is characterized by dwarf and low shrub tundra,
with mossy carpets and moist peaty soils [Walker et al., 2002].
Additional references:
Brabets, T. P., B. Wang, and R. H. Meade (2000), Environmental and hydrological overview of the
Yukon River Basin, Alaska and Canada, in US Geological Survey Water Resources Investigations
Report 99-4204, pp. 106.
FAO (2001), Global ecological zoning for the global forest resources assessment 2000, Final Report
For Dep., Food and Agricul. Org., U.N., Rome.
Hjort, S. (1971), Torne och Kalix älvar, del 1. Allmän beskrivning, Uppsala, Universitet, UNGI.
Rapport, Uppsala.
Walker, D. A., W. A. Gould, H. A. Maier, and M. K. Raynolds (2002), The Circumpolar Arctic
Vegetation Map: AVHRR-derived base maps, environmental controls, and integrated mapping
procedures, Intl. J. Remote Sens., 23, 4551-4570.
2
Sediment
Solvent extraction
(DCM:methanol, 2:1)
Total lipid extract
Residue
Saponification &
extraction at pH 7
Neutral
fraction
Silica gel
column
AgNO3impregnated
silica column
n-Alkanes
Alkaline hydrolysis
(1 M KOH, 100 °C, 3 h)
Aqueous
residue
Residue
Hydrolysis products
Saponification &
extraction at pH ~14
Acidification &
extraction at pH 2
Acid
fraction
Neutral
fraction
CuO oxidation
SPE cartridges
(ENVI-18 & LC-NH2)
Aqueous
residue
Lignin &
hydroxy
phenols
Acidification &
extraction at pH 2
Methylation
Silica gel
column
Acid
fraction
AgNO3impregnated
silica column
Methylation
Silica gel
column
FAMEs
Hex: EtOAc
(95:5)
Hex: EtOAc (4:1)
AgNO3impregnated
silica column
AgNO3impregnated
silica column
Hex
b-FAMEs
DCM
EtOAc
di- & triHydroxy
FAMEs
Hydroxy
FAMEs
DAMEs
Figure S1. Procedures of biomarker extraction and purification used in this study. Compounds in
the shaded boxes were selected for 14C analysis. DCM: dichloromethane; Hex: hexane; EtOAc:
ethyl acetate; SPE: solid phase extraction; FAME: fatty acid methyl ester; DAME: diacid
dimethyl ester. Refer to Materials and Methods and Feng et al. [2015] for detailed descriptions.
Please note that n-alkanes and FAMEs were separated from the total lipid extracts using slightly
different procedures (involving Bond-Elute column chromatography) for the Kalix and GRAR
sediments (details in van Dongen et al. [2008a]).
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Figure S2. Logarithmic correlations between the abundance-weighted average ∆14C values of terrestrial lipids and total permafrost coverage
(including continuous, discontinuous, sporadic and isolated permafrost in Table 1). Plant wax lipids include C27,29,31 n-alkanes and C24,26,28 fatty
acids; DAs: diacids.
4
Table S1. The ∆14C values of individual lipid and phenol compounds and their abundanceweighted averages in the arctic river sediments (‰). All values are corrected for procedural
blanks with the standard errors of analytical measurement propagated. The ∆14C values of nalkanes and fatty acids (FAs) in Mackenzie and Eurasian arctic rivers are derived from Drenzek
et al. [2007] and Gustafsson et al. [2011], respectively. The ∆14C values of lignin and hydroxy
phenols in Eurasian arctic rivers are also found in Feng et al. [2013a]. Detailed concentration data
are in Feng et al. [2015].
5
Table S2. Comparison of ∆14C values of the same sample measured at two AMS facilities
(NOSAMS and ETH Zürich). All values are corrected for procedural blanks with the standard
errors of analytical measurement propagated.
Sample content
AMS #
80884
Ob' Syringaldehyde
Acros Vanillic acid
Acros Acetovanillone
Sigma Vanillin
Facility
NOSAMS
Size
(μg C)
Fm
∆14C (‰)
38
0.6438 ± 0.0082
-361 ± 8
43766.1.1 ETH
16
0.6643 ± 0.0246
-341 ± 25
80286
182
0.0053 ± 0.0014
-995 ± 1
45131.1.1 ETH
23
0.0386 ± 0.0102
-962 ± 10
80287
163
0.0241 ± 0.0016
-976 ± 2
47488.1.1 ETH
37
0.0260 ± 0.0061
-974 ± 6
78965
152
1.1343 ± 0.0080
126 ± 8
20
1.1503 ± 0.0316
142 ± 32
NOSAMS
NOSAMS
NOSAMS
45129.1.1 ETH
6