Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia
Oxygen stable isotopes (δ18O) of biogenic sedimentary components from lake sediment archives, such as ostracod valves, are frequently used for palaeoclimatic reconstructions. However, the effects of host water isotope changes, temperature-dependent fractionations, and vital effects on the isotopic r...
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221694_v529_nP2_p600_Mayr http://hdl.handle.net/20.500.12110/paper_00221694_v529_nP2_p600_Mayr |
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paper:paper_00221694_v529_nP2_p600_Mayr2023-06-08T14:46:53Z Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia Laprida, Cecilia Ramon Mercau, Maria Josefina 18O/16O ratios Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperature Animals Cellulose Fractionation Lakes Oxygen Repair Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperatures Isotopes aquatic organism biochemical composition biogenic deposit calcite calibration cellulose dicotyledon fly isotopic fractionation lacustrine deposit larva macrophyte moss ostracod oxygen isotope ratio paleoclimate proxy climate record reconstruction seasonality stable isotope stream subfossil water temperature Patagonia Bryophyta Chironomidae Myriophyllum Ostracoda Oxygen stable isotopes (δ18O) of biogenic sedimentary components from lake sediment archives, such as ostracod valves, are frequently used for palaeoclimatic reconstructions. However, the effects of host water isotope changes, temperature-dependent fractionations, and vital effects on the isotopic ratios of such biogenic proxies often cannot be disentangled. Here, δ18O values of ostracod valves, head capsules of chironomid larvae and aquatic macrophyte cellulose from various lake and stream sites in southern Patagonia (41-52°S) are compared with δ18O values of their host waters. The best correlation between δ18O values of bioproxy and host water was obtained for aquatic cellulose exhibiting a slope of the regression of almost unity. Chironomid head capsules showed a strong correlation, but the data set was rather small (seven sites). The δ18O values of ostracod valves showed strong inter-specific vital effects. Strong offsets of ostracod values from isotopic equilibrium are possibly explained by re-working of subfossil valves, seasonality effects or different chemical composition of host waters. A weak, but significant temperature dependency of oxygen isotope fractionation was observed for cellulose of one aquatic taxon (Myriophyllum) and for ostracod calcite, but not for chironomids and aquatic moss cellulose. The present dataset suggests that δ18O values of aquatic cellulose are the most reliable proxy for host water isotope reconstructions, but clearly more investigations are needed to substantiate this finding. © 2014 Elsevier B.V. Fil:Laprida, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ramón-Mercau, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221694_v529_nP2_p600_Mayr http://hdl.handle.net/20.500.12110/paper_00221694_v529_nP2_p600_Mayr |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
18O/16O ratios Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperature Animals Cellulose Fractionation Lakes Oxygen Repair Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperatures Isotopes aquatic organism biochemical composition biogenic deposit calcite calibration cellulose dicotyledon fly isotopic fractionation lacustrine deposit larva macrophyte moss ostracod oxygen isotope ratio paleoclimate proxy climate record reconstruction seasonality stable isotope stream subfossil water temperature Patagonia Bryophyta Chironomidae Myriophyllum Ostracoda |
spellingShingle |
18O/16O ratios Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperature Animals Cellulose Fractionation Lakes Oxygen Repair Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperatures Isotopes aquatic organism biochemical composition biogenic deposit calcite calibration cellulose dicotyledon fly isotopic fractionation lacustrine deposit larva macrophyte moss ostracod oxygen isotope ratio paleoclimate proxy climate record reconstruction seasonality stable isotope stream subfossil water temperature Patagonia Bryophyta Chironomidae Myriophyllum Ostracoda Laprida, Cecilia Ramon Mercau, Maria Josefina Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
topic_facet |
18O/16O ratios Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperature Animals Cellulose Fractionation Lakes Oxygen Repair Climate proxies Isotope fractionation Lacustrine systems Stable isotopes Water temperatures Isotopes aquatic organism biochemical composition biogenic deposit calcite calibration cellulose dicotyledon fly isotopic fractionation lacustrine deposit larva macrophyte moss ostracod oxygen isotope ratio paleoclimate proxy climate record reconstruction seasonality stable isotope stream subfossil water temperature Patagonia Bryophyta Chironomidae Myriophyllum Ostracoda |
description |
Oxygen stable isotopes (δ18O) of biogenic sedimentary components from lake sediment archives, such as ostracod valves, are frequently used for palaeoclimatic reconstructions. However, the effects of host water isotope changes, temperature-dependent fractionations, and vital effects on the isotopic ratios of such biogenic proxies often cannot be disentangled. Here, δ18O values of ostracod valves, head capsules of chironomid larvae and aquatic macrophyte cellulose from various lake and stream sites in southern Patagonia (41-52°S) are compared with δ18O values of their host waters. The best correlation between δ18O values of bioproxy and host water was obtained for aquatic cellulose exhibiting a slope of the regression of almost unity. Chironomid head capsules showed a strong correlation, but the data set was rather small (seven sites). The δ18O values of ostracod valves showed strong inter-specific vital effects. Strong offsets of ostracod values from isotopic equilibrium are possibly explained by re-working of subfossil valves, seasonality effects or different chemical composition of host waters. A weak, but significant temperature dependency of oxygen isotope fractionation was observed for cellulose of one aquatic taxon (Myriophyllum) and for ostracod calcite, but not for chironomids and aquatic moss cellulose. The present dataset suggests that δ18O values of aquatic cellulose are the most reliable proxy for host water isotope reconstructions, but clearly more investigations are needed to substantiate this finding. © 2014 Elsevier B.V. |
author |
Laprida, Cecilia Ramon Mercau, Maria Josefina |
author_facet |
Laprida, Cecilia Ramon Mercau, Maria Josefina |
author_sort |
Laprida, Cecilia |
title |
Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
title_short |
Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
title_full |
Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
title_fullStr |
Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
title_full_unstemmed |
Oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - Results of a calibration study in Patagonia |
title_sort |
oxygen isotope ratios of chironomids, aquatic macrophytes and ostracods for lake-water isotopic reconstructions - results of a calibration study in patagonia |
publishDate |
2015 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221694_v529_nP2_p600_Mayr http://hdl.handle.net/20.500.12110/paper_00221694_v529_nP2_p600_Mayr |
work_keys_str_mv |
AT lapridacecilia oxygenisotoperatiosofchironomidsaquaticmacrophytesandostracodsforlakewaterisotopicreconstructionsresultsofacalibrationstudyinpatagonia AT ramonmercaumariajosefina oxygenisotoperatiosofchironomidsaquaticmacrophytesandostracodsforlakewaterisotopicreconstructionsresultsofacalibrationstudyinpatagonia |
_version_ |
1768544395844386816 |