Can stable oxygen and hydrogen isotopes from Australian subfossil Chironomus head capsules be used as proxies for past temperature change?
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- 作者：Jie Christine Chang ; James Shulmeister ; Craig Woodward…
- 关键词：Chironomid head capsules ; δ18O ; δ2H ; South ; east Australia ; Vital effects ; Nutrients ; Salinity ; Aridity ; Evaporation ; Temperature reconstructions
- 刊名：Journal of Paleolimnology
- 出版年：2016
- 出版时间：December 2016
- 年：2016
- 卷：56
- 期：4
- 页码：331-348
- 全文大小：1,015 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Environment
Environment
Sedimentology
Climate Change
Physical Geography
Hydrobiology
Geology - 出版者：Springer Netherlands
- ISSN：1573-0417
- 卷排序：56
文摘
This paper presents the first systematic investigation of stable isotopes (δ18O and δ2H) from the subfossil chironomid head capsules (HCs) of a single taxon (Chironomus). The study focuses on sixteen south-eastern Australian lakes and investigates the potential of Chironomus spp. HC stable isotopes to reconstruct past temperature changes from these lakes. The relationship between δ18O values of Chironomus spp. HCs from Australian oligotrophic to mesotrophic lakes in humid areas and air temperature appears robust (r = 0.88) and in line with results from European lakes. Similar results were obtained for δ2H values and temperature (r = 0.94). For lakes that are located in semi-arid and sub-humid areas that have high evaporation compared to precipitation, and often long water residence time, the temperature relationship is not robust. This is due to the evaporative enrichment of δ18O values in lake water and the effect of salinity and higher nutrient status. Vital effects may also play a role. The overall findings of this study are that both Chironomus spp. HC δ18O and δ2H are potentially valuable tools for reconstructing temperature in cooler, low nutrient and low salinity lakes of Australia. In warmer, sub-humid to semi-arid regions, δ18O and δ2H may provide valuable information about past changes in hydrological conditions.