A framework for 210Pb model selection and its application to 37 cores from Eastern Canada to identify the dynamics and drivers of lake sedimentation rates
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Authors
Baud, Alexandre
Aulard, Candice
Ghanbari, Hamid
Fradette, Maxime
Antoniades, Dermot
del Giorgio, Paul
Huot, Yannick
Francus, Pierre
Smol, John
Gregory-Eaves, Irene
Date
2022-04-26
Type
journal article
Language
en
Keyword
210Pb , CFCS , CIC , CRS , Dating models , Land use , Paleolimnology , Radiochronology , Sedimentation
Alternative Title
Abstract
Lake sedimentation rate represents a synthetic metric of ecosystem functioning. Many localized studies have reported a significant association between land use/land cover changes and lake sediment mass accumulation rates, with a few global syntheses echoing these findings at larger scales. In the literature, studies evaluating lead-210 (210Pb) for establishing sediment chronologies will report at least one of three dating models, but the constant rate of supply (CRS) model is the most widely used. However, it is often unclear how or why this model is selected, despite its influence on the interpretation of many subsequent analyses about ecosystem dynamics and functioning. It would thus be advantageous to design an objective and semi-automated way of choosing among dating models. We measured radioisotopic activities in 37 sediment cores across four ecozones of Eastern Canada and developed an approach to assess model fit for the three commonly applied dating models. The derived chronologies were then used to evaluate the spatial and temporal variation in sedimentation rates across four ecozones in Canada (covering a surface area of 2.2 × 106 km2). We observed a recent increase in lake sedimentation rates across most lakes, as has been observed globally, albeit with significant differences in the magnitude of sedimentation rates across ecozones. Across all lakes, we found that regional human population counts and mean annual air temperatures were significant temporal predictors of variation in mass accumulation rates. Overall, this analytical framework offers an objective approach for assessing fit and selecting among sediment age models, which contributes to a more robust quantification of sedimentation rates. With this first application, we provide a quantitative assessment of how lake sedimentation rates have varied across a northern lake-rich region and have responded to environmental change.
Description
This is the peer reviewed version of the following article: Baud, A., Aulard, C., Ghanbari, H., Fradette, M., Antoniades, D., del Giorgio, P. et al. (2022) A framework for 210Pb model selection and its application to 37 cores from Eastern Canada to identify the dynamics and drivers of lake sedimentation rates. Earth Surface Processes and Landforms, 1– 13, which has been published in final form at https://doi.org/10.1002/esp.5391. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
Citation
Baud, A., Aulard, C., Ghanbari, H., Fradette, M., Antoniades, D., del Giorgio, P. et al. (2022) A framework for 210Pb model selection and its application to 37 cores from Eastern Canada to identify the dynamics and drivers of lake sedimentation rates. Earth Surface Processes and Landforms, 1– 13. Available from: https://doi.org/10.1002/esp.5391
Publisher
Wiley