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Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes

Anderson, N. J. ; Appleby, P. G. ; Bindler, R. ; Renberg, I. ; Conley, D. J. LU ; Fritz, S. C. LU ; Jones, V. J. ; Whiteford, E. J. and Yang, H. (2019) In Ecosystems
Abstract


Lakes are a key feature of arctic landscapes and can be an important component of regional organic carbon (OC) budgets, but C burial rates are not well estimated.
210
Pb-dated sediment cores and carbon and organic matter (as loss-on-ignition) content were used to estimate OC burial for 16 lakes in SW Greenland. Burial rates were corrected for sediment focusing using the
210
Pb flux method. The study lakes span a... (More)


Lakes are a key feature of arctic landscapes and can be an important component of regional organic carbon (OC) budgets, but C burial rates are not well estimated.
210
Pb-dated sediment cores and carbon and organic matter (as loss-on-ignition) content were used to estimate OC burial for 16 lakes in SW Greenland. Burial rates were corrected for sediment focusing using the
210
Pb flux method. The study lakes span a range of water chemistries (conductivity range 25–3400 µS cm
−1
), areas (< 4–100 ha) and maximum depths (~ 10–50 m). The regional average focusing-corrected OC accumulation rate was ~ 2 g C m
−2
 y
−1
prior to ~ 1950 and 3.6 g C m
−2
 y
−1
after 1950. Among-lake variability in post-1950 OC AR was correlated with in-lake dissolved organic carbon concentration, conductivity, altitude and location along the fjord. Twelve lakes showed an increase in mean OC AR over the analyzed time period, ~ 1880–2000; as the study area was cooling until recently, this increase is probably attributable to other global change processes, for example, altered inputs of N or P. There are ~ 20,000 lakes in the study area ranging from ~ 1 ha to more than 130 km
2
, although over 83% of lakes are less than 10 ha. Extrapolating the mean post-1950 OC AR (3.6 g C m
−2
 y
−1
) to all lakes larger than 1000 ha and applying a lower rate of ~ 2 g C m
−2
 y
−1
to large lakes (> 1000 ha) suggests a regional annual lake OC burial rate of ~ 10.14 × 10
9
 g C y
−1
post 1950. Given the low C content of soils in this area, lakes represent a substantial regional C store.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
arctic, biogenic silica, diatoms, DOC, nitrogen, soil carbon, tundra
in
Ecosystems
publisher
Springer
external identifiers
  • scopus:85065196296
ISSN
1432-9840
DOI
10.1007/s10021-019-00368-8
language
English
LU publication?
yes
id
300e2583-d0e4-487b-837c-6cab3a6612cd
date added to LUP
2019-05-24 13:40:04
date last changed
2019-11-25 09:30:46
@article{300e2583-d0e4-487b-837c-6cab3a6612cd,
  abstract     = {<p><br>
                                                         Lakes are a key feature of arctic landscapes and can be an important component of regional organic carbon (OC) budgets, but C burial rates are not well estimated.                              <br>
                            <sup>210</sup><br>
                                                         Pb-dated sediment cores and carbon and organic matter (as loss-on-ignition) content were used to estimate OC burial for 16 lakes in SW Greenland. Burial rates were corrected for sediment focusing using the                              <br>
                            <sup>210</sup><br>
                                                         Pb flux method. The study lakes span a range of water chemistries (conductivity range 25–3400 µS cm                             <br>
                            <sup>−1</sup><br>
                                                         ), areas (&lt; 4–100 ha) and maximum depths (~ 10–50 m). The regional average focusing-corrected OC accumulation rate was ~ 2 g C m                             <br>
                            <sup>−2</sup><br>
                                                          y                             <br>
                            <sup>−1</sup><br>
                                                          prior to ~ 1950 and 3.6 g C m                             <br>
                            <sup>−2</sup><br>
                                                          y                             <br>
                            <sup>−1</sup><br>
                                                          after 1950. Among-lake variability in post-1950 OC AR was correlated with in-lake dissolved organic carbon concentration, conductivity, altitude and location along the fjord. Twelve lakes showed an increase in mean OC AR over the analyzed time period, ~ 1880–2000; as the study area was cooling until recently, this increase is probably attributable to other global change processes, for example, altered inputs of N or P. There are ~ 20,000 lakes in the study area ranging from ~ 1 ha to more than 130 km                             <br>
                            <sup>2</sup><br>
                                                         , although over 83% of lakes are less than 10 ha. Extrapolating the mean post-1950 OC AR (3.6 g C m                             <br>
                            <sup>−2</sup><br>
                                                          y                             <br>
                            <sup>−1</sup><br>
                                                         ) to all lakes larger than 1000 ha and applying a lower rate of ~ 2 g C m                             <br>
                            <sup>−2</sup><br>
                                                          y                             <br>
                            <sup>−1</sup><br>
                                                          to large lakes (&gt; 1000 ha) suggests a regional annual lake OC burial rate of ~ 10.14 × 10                             <br>
                            <sup>9</sup><br>
                                                          g C y                             <br>
                            <sup>−1</sup><br>
                                                          post 1950. Given the low C content of soils in this area, lakes represent a substantial regional C store.                         <br>
                        </p>},
  author       = {Anderson, N. J. and Appleby, P. G. and Bindler, R. and Renberg, I. and Conley, D. J. and Fritz, S. C. and Jones, V. J. and Whiteford, E. J. and Yang, H.},
  issn         = {1432-9840},
  language     = {eng},
  publisher    = {Springer},
  series       = {Ecosystems},
  title        = {Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes},
  url          = {http://dx.doi.org/10.1007/s10021-019-00368-8},
  doi          = {10.1007/s10021-019-00368-8},
  year         = {2019},
}