Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s
In monomictic lakes, the potential intensification of hypolimnetic deoxygenation due to human activities and climate change threatens lake ecosystems and water quality. Understanding the trends and mechanisms of hypolimnetic deoxygenation would allow for the adaptive management of monomictic lakes....
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Elsevier
2023-10-01
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| Series: | Ecological Indicators |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X23007094 |
| _version_ | 1797683162582614016 |
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| author | Yongdong Zhang Huan Fu Huihui Chen Zhengwen Liu |
| author_facet | Yongdong Zhang Huan Fu Huihui Chen Zhengwen Liu |
| author_sort | Yongdong Zhang |
| collection | DOAJ |
| description | In monomictic lakes, the potential intensification of hypolimnetic deoxygenation due to human activities and climate change threatens lake ecosystems and water quality. Understanding the trends and mechanisms of hypolimnetic deoxygenation would allow for the adaptive management of monomictic lakes. This study investigated the trends and drivers of hypolimnetic deoxygenation in Lake Fuxian (a monomictic lake in south-western China) over the past 150 years using paleolimnological evidence and historical records. Analysis of enrichment factors for molybdenum (Mo), uranium (U), and vanadium (V), and ratios of U/thorium (Th), pristane (Pr)/phytane (Ph), and total organic carbon (TOC)/total phosphorus (TP) in a dated sediment core indicated that the extent of hypolimnetic deoxygenation was relatively low before 1994 and increased substantially thereafter. Nutrient monitoring records and sediment n-alkane proxies indicated notable eutrophication of the lake since 1986 and a greater degree of human disturbance in the catchment between 1951 and 1967. Due to their asynchronous occurrence, eutrophication and catchment disturbance could not be the major drivers of hypolimnetic deoxygenation. Interestingly, climate records indicated that the local ambient temperature exhibited similar trends to that of hypolimnetic deoxygenation, including markedly higher temperatures after 1994. This implies that prolonged water column stratification due to climate warming could have promoted hypolimnetic deoxygenation by limiting oxygen exchange between the upper and lower water columns. In comparing the results with those of Lake Erhai, another monomictic lake with contrasting morphology and hydrology characteristics, we found that the low surface area/depth ratio and long water residence time in Lake Fuxian enable dissolved oxygen of the lake hypolimnion vulnerable to temperature over the lake. |
| first_indexed | 2024-03-12T00:10:32Z |
| format | Article |
| id | doaj.art-d17a30ccb6254c02abf01847a24eb21e |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-03-12T00:10:32Z |
| publishDate | 2023-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-d17a30ccb6254c02abf01847a24eb21e2023-09-16T05:29:18ZengElsevierEcological Indicators1470-160X2023-10-01154110567Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990sYongdong Zhang0Huan Fu1Huihui Chen2Zhengwen Liu3School of Geography, South China Normal University, Guangzhou 510631, China; Corresponding authors.School of Geography, South China Normal University, Guangzhou 510631, ChinaState Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, ChinaState Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Corresponding authors.In monomictic lakes, the potential intensification of hypolimnetic deoxygenation due to human activities and climate change threatens lake ecosystems and water quality. Understanding the trends and mechanisms of hypolimnetic deoxygenation would allow for the adaptive management of monomictic lakes. This study investigated the trends and drivers of hypolimnetic deoxygenation in Lake Fuxian (a monomictic lake in south-western China) over the past 150 years using paleolimnological evidence and historical records. Analysis of enrichment factors for molybdenum (Mo), uranium (U), and vanadium (V), and ratios of U/thorium (Th), pristane (Pr)/phytane (Ph), and total organic carbon (TOC)/total phosphorus (TP) in a dated sediment core indicated that the extent of hypolimnetic deoxygenation was relatively low before 1994 and increased substantially thereafter. Nutrient monitoring records and sediment n-alkane proxies indicated notable eutrophication of the lake since 1986 and a greater degree of human disturbance in the catchment between 1951 and 1967. Due to their asynchronous occurrence, eutrophication and catchment disturbance could not be the major drivers of hypolimnetic deoxygenation. Interestingly, climate records indicated that the local ambient temperature exhibited similar trends to that of hypolimnetic deoxygenation, including markedly higher temperatures after 1994. This implies that prolonged water column stratification due to climate warming could have promoted hypolimnetic deoxygenation by limiting oxygen exchange between the upper and lower water columns. In comparing the results with those of Lake Erhai, another monomictic lake with contrasting morphology and hydrology characteristics, we found that the low surface area/depth ratio and long water residence time in Lake Fuxian enable dissolved oxygen of the lake hypolimnion vulnerable to temperature over the lake.http://www.sciencedirect.com/science/article/pii/S1470160X23007094Hypolimnetic deoxygenationLake FuxianLipid biomarkersGeochemical recordsClimate warmingEutrophication |
| spellingShingle | Yongdong Zhang Huan Fu Huihui Chen Zhengwen Liu Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s Ecological Indicators Hypolimnetic deoxygenation Lake Fuxian Lipid biomarkers Geochemical records Climate warming Eutrophication |
| title | Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s |
| title_full | Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s |
| title_fullStr | Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s |
| title_full_unstemmed | Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s |
| title_short | Climate-driven intensification of hypolimnetic deoxygenation in Lake Fuxian, a monomictic lake in south-western China, since the 1990s |
| title_sort | climate driven intensification of hypolimnetic deoxygenation in lake fuxian a monomictic lake in south western china since the 1990s |
| topic | Hypolimnetic deoxygenation Lake Fuxian Lipid biomarkers Geochemical records Climate warming Eutrophication |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X23007094 |
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