We evaluated the response of a rotifer community to environmental changes in five shallow lakes in the middle reach of the Changjiang （Yangtze） River in summer and autumn 2010. These five lakes differed in trophic s...We evaluated the response of a rotifer community to environmental changes in five shallow lakes in the middle reach of the Changjiang （Yangtze） River in summer and autumn 2010. These five lakes differed in trophic status and rotifer community structure. Twenty-nine rotifer species were collected, of which Keratella cochlearis, Polyarthra dolichoptera, and Trichocerca elongate were dominant. The mean density, Shannon-Wiener diversity, and equitability among the five lakes differed significantly （P〈0.05）. The mean rotifer density was positively correlated with trophic state. The diversity was higher in lakes with high macrophyte coverage. The composition of rotifer species was closely associated with the trophic gradient. Five environmental variables, Secchi depth, conductivity, TN, NHa-N, and TP, significantly affected the composition of rotifer species. Keratella quadrata, Brachionus calyciflorus, and B. forficula were more common in eutrophic conditions. Our results suggest that eutrophication has a significant influence on the rotifer community structure and highlight the potential for using rotifer community structure as an indicator of trophic status in subtropical lakes.展开更多
Fish communities in a （third-order） intertidal creek in Dongtan marsh in the Changjiang （Yangtze） River estuary were investigated seasonally for one year. A total of 1 996 fish specimens （10 967.8 g） comprising ...Fish communities in a （third-order） intertidal creek in Dongtan marsh in the Changjiang （Yangtze） River estuary were investigated seasonally for one year. A total of 1 996 fish specimens （10 967.8 g） comprising 26 species and 15 families were collected. Abundances of fish communities in the intertidal salt marsh creek were primarily dominated by Boleophthalmus pectinirostris （19.8%）, Collichthys lucidus （18.6%）, Periophthalmus magnuspinnatus （18.2%）, Liza haematocheilus （17.9%）, and secondarily by Mugilogobius abel （8.5%）, L. carinatus （7.2%）, Odontamblyopus lacepedii （4.3%）, and Acanthogobius ommaturus （3.9%）; another 18 species were present only occasionally. Non-MDS ordination and SIMPER analysis indicated that there were two fish communities in the intertidal salt marsh creek. In spring, the communities were dominated by B. pectinirostris, P. magnuspinnatus, C. lucidus and M. abei; in summer, autumn, and winter by L. haematocheilus, L. carinatus, A. ommaturus and O. lacepedii. Some species showed strong habitat selection; L. carinatus and P magnuspinnatus were distributed mainly in the upper and middle creek, while B. pectinirostris, M. abei and O. lacepedii inhabited the middle and lower creek. The study indicated that the salt marshes of the Changjiang River estuary are an important nursery and feeding habitat for many fishes and should be protected.展开更多
The restoration of political radicalism in China can be attributed to a number of factors; similarly, the successful construction of a civil society to un- tangle the mess caused by the transformation does not rely on...The restoration of political radicalism in China can be attributed to a number of factors; similarly, the successful construction of a civil society to un- tangle the mess caused by the transformation does not rely on spontaneous fulfill- ment of the society itself, for it involves more factors than have been realized and discussed, such as the state （i.e., the government）, the ruling party, society, and the context of globalization. Without a comprehensive study on the cause of this problem, any prescriptive suggestion or discussion on how to go beyond radicalism is no more than an idealistic path for China＇s political reconstruction.展开更多
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.20130356)the National Key Technology Research and Development Program of China(No.2012BAD25B08)the National Natural Science Foundation of China(Nos.30830025,31201994)
文摘We evaluated the response of a rotifer community to environmental changes in five shallow lakes in the middle reach of the Changjiang （Yangtze） River in summer and autumn 2010. These five lakes differed in trophic status and rotifer community structure. Twenty-nine rotifer species were collected, of which Keratella cochlearis, Polyarthra dolichoptera, and Trichocerca elongate were dominant. The mean density, Shannon-Wiener diversity, and equitability among the five lakes differed significantly （P〈0.05）. The mean rotifer density was positively correlated with trophic state. The diversity was higher in lakes with high macrophyte coverage. The composition of rotifer species was closely associated with the trophic gradient. Five environmental variables, Secchi depth, conductivity, TN, NHa-N, and TP, significantly affected the composition of rotifer species. Keratella quadrata, Brachionus calyciflorus, and B. forficula were more common in eutrophic conditions. Our results suggest that eutrophication has a significant influence on the rotifer community structure and highlight the potential for using rotifer community structure as an indicator of trophic status in subtropical lakes.
基金Supported by Special Research Fund for the National Non-profit Institutes (East China Sea Fisheries Research Institute) (No.2007M03) and Administration Bureau of Virescence of Shanghai Municipality
文摘Fish communities in a （third-order） intertidal creek in Dongtan marsh in the Changjiang （Yangtze） River estuary were investigated seasonally for one year. A total of 1 996 fish specimens （10 967.8 g） comprising 26 species and 15 families were collected. Abundances of fish communities in the intertidal salt marsh creek were primarily dominated by Boleophthalmus pectinirostris （19.8%）, Collichthys lucidus （18.6%）, Periophthalmus magnuspinnatus （18.2%）, Liza haematocheilus （17.9%）, and secondarily by Mugilogobius abel （8.5%）, L. carinatus （7.2%）, Odontamblyopus lacepedii （4.3%）, and Acanthogobius ommaturus （3.9%）; another 18 species were present only occasionally. Non-MDS ordination and SIMPER analysis indicated that there were two fish communities in the intertidal salt marsh creek. In spring, the communities were dominated by B. pectinirostris, P. magnuspinnatus, C. lucidus and M. abei; in summer, autumn, and winter by L. haematocheilus, L. carinatus, A. ommaturus and O. lacepedii. Some species showed strong habitat selection; L. carinatus and P magnuspinnatus were distributed mainly in the upper and middle creek, while B. pectinirostris, M. abei and O. lacepedii inhabited the middle and lower creek. The study indicated that the salt marshes of the Changjiang River estuary are an important nursery and feeding habitat for many fishes and should be protected.
文摘The restoration of political radicalism in China can be attributed to a number of factors; similarly, the successful construction of a civil society to un- tangle the mess caused by the transformation does not rely on spontaneous fulfill- ment of the society itself, for it involves more factors than have been realized and discussed, such as the state （i.e., the government）, the ruling party, society, and the context of globalization. Without a comprehensive study on the cause of this problem, any prescriptive suggestion or discussion on how to go beyond radicalism is no more than an idealistic path for China＇s political reconstruction.
