1 Introduction The most valuable for the task of climate reconstruction are the time series with an annual resolution,which allows to reveal natural periodicity and pass to the search for mechanisms of regional and gl...1 Introduction The most valuable for the task of climate reconstruction are the time series with an annual resolution,which allows to reveal natural periodicity and pass to the search for mechanisms of regional and global climatic changes.Bottom sediments of lakes are one of the best climate archives in addition to tree ring series,ice cores etc.展开更多
1 Introduction Soda Lake Doroninskoye(Uleoti District of Transbaikalian Region,Russia)belongs to a rare type of meromictic basins.For meromictic basins,the vertical stratification in the form of sufficiently thin wate...1 Introduction Soda Lake Doroninskoye(Uleoti District of Transbaikalian Region,Russia)belongs to a rare type of meromictic basins.For meromictic basins,the vertical stratification in the form of sufficiently thin water layers with significantly differing physical and chemical properties is typical,as well as peculiar biota.The main characteristics of the lake Doroninskoye are:展开更多
For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water l...For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water levels.Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years,the wintering waterbird populations have remained relatively stable.Hence,the mechanism of maintaining the stability is worth exploring.This study aimed to compare the distribution of vegetation and herbivorous wa-terbirds in 2015-2016 and 2016-2017,focusing on three shallow sub-lakes and one main lake are.The results showed that the emergence of tubers and the growth of Carex spp.provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level.Shallow sub-lakes supported almost all of the tuber-eating waterbirds(1.42-1.62×10^(5))and most geese(1.34-1.53×10^(6)).However,the main lake area,covered with Persicaria hydropiper,did not provide adequate and accessible food.This resulted in almost no distribution of tuber-eating waterbirds,with only a few geese congregating in early winter.Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake.Therefore,we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.展开更多
Seasonal water-level fluctuations (WLF) play a dominate role in lacustrine ecosys- tems. River-lake interaction is a direct factor in changes of seasonal lake WLF, especially for those lakes naturally connected to u...Seasonal water-level fluctuations (WLF) play a dominate role in lacustrine ecosys- tems. River-lake interaction is a direct factor in changes of seasonal lake WLF, especially for those lakes naturally connected to upstream and downstream rivers. During the past decade, the modification of WLF in the Poyang Lake (the largest freshwater lake in China) has caused intensified flood and irrigation crises, reduced water availability, compromised water quality and extensive degradation of the lake ecosystem. There has been a conjecture as to whether the modification was caused by its interactions with Yangtze River. In this study, we investi- gated the variations of seasonal WLF in China's Poyang Lake by comparing the water levels during the four distinct seasons (the dry season, the rising season, the flood season, and the retreating season) before and after 2003 when the Three Gorge Dam operated. The Water Surface Slope (WSS) was used as a representative parameter to measure the changes in river-lake interaction and its impacts on seasonal WLF. The results showed that the magni- tude of seasonal WLF has changed considerably since 2003; the seasonal WLF of the Poy- ang Lake have been significantly altered by the fact that the water levels both rise and retreat earlier in the season and lowered water levels in general. The fluctuations of river-lake in- teractions, in particular the changes during the retreating season, are mainly responsible for these variations in magnitude of seasonal WLF. This study demonstrates that WSS is a rep- resentative parameter to denote river-lake interactions, and the results indicate that more emphasis should be placed on the decrease of the Poyang Lake caused by the lowered water levels of the Yangtze River, especially in the retreating season.展开更多
基金supported by the Integration projects of the Siberian Branch, Russian Academy of Sciences (№ 34 and № 56)
文摘1 Introduction The most valuable for the task of climate reconstruction are the time series with an annual resolution,which allows to reveal natural periodicity and pass to the search for mechanisms of regional and global climatic changes.Bottom sediments of lakes are one of the best climate archives in addition to tree ring series,ice cores etc.
基金supported by the Integration project of SB RAS №56
文摘1 Introduction Soda Lake Doroninskoye(Uleoti District of Transbaikalian Region,Russia)belongs to a rare type of meromictic basins.For meromictic basins,the vertical stratification in the form of sufficiently thin water layers with significantly differing physical and chemical properties is typical,as well as peculiar biota.The main characteristics of the lake Doroninskoye are:
基金funded by the Poyang Lake Water Conservancy Project Office of the Department of Water Resources,Jiangxi Province,China(KT201537)the National Natural Science Foundation of China(Grant No.32360285)the National Geographic Air and Water Con-servation Fund(GEFC07-15).
文摘For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water levels.Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years,the wintering waterbird populations have remained relatively stable.Hence,the mechanism of maintaining the stability is worth exploring.This study aimed to compare the distribution of vegetation and herbivorous wa-terbirds in 2015-2016 and 2016-2017,focusing on three shallow sub-lakes and one main lake are.The results showed that the emergence of tubers and the growth of Carex spp.provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level.Shallow sub-lakes supported almost all of the tuber-eating waterbirds(1.42-1.62×10^(5))and most geese(1.34-1.53×10^(6)).However,the main lake area,covered with Persicaria hydropiper,did not provide adequate and accessible food.This resulted in almost no distribution of tuber-eating waterbirds,with only a few geese congregating in early winter.Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake.Therefore,we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.
基金National Basic Research Program of China ("973" Program), No.2012CB417006 National Natural Science Foundation of China, No.41171024 No.41271500
文摘Seasonal water-level fluctuations (WLF) play a dominate role in lacustrine ecosys- tems. River-lake interaction is a direct factor in changes of seasonal lake WLF, especially for those lakes naturally connected to upstream and downstream rivers. During the past decade, the modification of WLF in the Poyang Lake (the largest freshwater lake in China) has caused intensified flood and irrigation crises, reduced water availability, compromised water quality and extensive degradation of the lake ecosystem. There has been a conjecture as to whether the modification was caused by its interactions with Yangtze River. In this study, we investi- gated the variations of seasonal WLF in China's Poyang Lake by comparing the water levels during the four distinct seasons (the dry season, the rising season, the flood season, and the retreating season) before and after 2003 when the Three Gorge Dam operated. The Water Surface Slope (WSS) was used as a representative parameter to measure the changes in river-lake interaction and its impacts on seasonal WLF. The results showed that the magni- tude of seasonal WLF has changed considerably since 2003; the seasonal WLF of the Poy- ang Lake have been significantly altered by the fact that the water levels both rise and retreat earlier in the season and lowered water levels in general. The fluctuations of river-lake in- teractions, in particular the changes during the retreating season, are mainly responsible for these variations in magnitude of seasonal WLF. This study demonstrates that WSS is a rep- resentative parameter to denote river-lake interactions, and the results indicate that more emphasis should be placed on the decrease of the Poyang Lake caused by the lowered water levels of the Yangtze River, especially in the retreating season.