Using sediment geochemical records to infer past lake-water total phosphorus concentrations at a site with high internal P loading, Lake Sobygaard, Denmark



Boyle, John ORCID: 0000-0002-1172-1079, Moyle, Madeleine, Sondergaard, Martin and Jeppesen, Erik
(2023) Using sediment geochemical records to infer past lake-water total phosphorus concentrations at a site with high internal P loading, Lake Sobygaard, Denmark. JOURNAL OF PALEOLIMNOLOGY, 69 (4). pp. 345-357.

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Abstract

<jats:title>Abstract</jats:title><jats:p>In lakes where phosphorus (P) supply is dominated by external loads, long-term mean lake-water total phosphorus (TP) concentrations can be successfully reconstructed from sediment P profiles and dating using the Sediment-Inferred lake-water Total Phosphorous (SI-TP) mass balance model. However, it has not yet been shown that the model is applicable at lakes with high internal P loading, where sediment diagenesis releases P to the water column and degrades the sediment P record. Here we apply the SI-TP model to Lake Søbygaard in Denmark, a shallow lake with exceptionally high internal P loading for several decades since the external loading was reduced by 80–90% in 1982. Our aim was to test the impact of this sediment degradation on P record integrity. Using six published sediment P records collected over the period 1985–2004, we applied the model without site-specific calibration. Degradation of the sediment P record by diagenesis was observed, and occurred at a rate consistent with theoretical models, offering a potential approach to correct for degradation. Even neglecting degradation, the resulting SI-TP record was found to be similar in magnitude and temporal trend to the corresponding monitored TP values. From this test of SI-TP model performance at Lake Søbygaard we conclude that the model has the potential to be more widely applied at lakes with high internal P loading.</jats:p>

Item Type: Article
Uncontrolled Keywords: Lake sediment geochemistry, Mass balance model, Retention coefficient, SI-TP, TP reconstruction
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 Mar 2023 11:37
Last Modified: 10 Mar 2023 13:00
DOI: 10.1007/s10933-022-00276-3
Open Access URL: https://doi.org/10.1007/s10933-022-00276-3
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3168685