The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic bio...The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.展开更多
对东方水韭(Isoёtes orientalis H.Liu et Q.F.Wang)2个自然样地(浙江松阳叔婆湾和小烂湖)生境土壤主要营养成分含量进行了比较分析,并对叔婆湾样地水体pH值进行了测定,在此基础上,对导致东方水韭濒危的土壤及水体因素进行了讨论。结...对东方水韭(Isoёtes orientalis H.Liu et Q.F.Wang)2个自然样地(浙江松阳叔婆湾和小烂湖)生境土壤主要营养成分含量进行了比较分析,并对叔婆湾样地水体pH值进行了测定,在此基础上,对导致东方水韭濒危的土壤及水体因素进行了讨论。结果显示:东方水韭叔婆湾样地的土壤有机质、总氮、速效磷、速效钾和总铁离子(包括Fe3+和Fe2+)含量分别为102.7 g.kg-1、3.1 g.kg-1、18.1μg.g-1、15.0μg.g-1和221.6μg.g-1;小烂湖样地土壤中上述营养成分的含量分别为122.8 g.kg-1、4.8 g.kg-1、13.7μg.g-1、7.1μg.g-1和240.0μg.g-1。小烂湖样地土壤中有机质、总氮和速效钾含量显著或极显著高于叔婆湾样地,2个样地间速效磷和总铁离子含量差异不显著,但2个样地土壤中速效钾含量极低、总铁离子含量丰富。叔婆湾样地中上、中、下游水体的pH值分别为pH6.35、pH6.53和pH6.49,略呈中性。分析结果表明,东方水韭2个自然样地的土壤均为有机质、总氮、速效磷以及总铁离子含量较为丰富且速效钾含量较低的土壤类型,土壤中速效钾极度缺乏和水体中性化很可能是限制东方水韭种群发展的重要环境因素。展开更多
基金This work was supported by the National Basic Research Program of China （No. 2011CB808800）, the National Natural Science Foundation of China （Grant Nos. 40930210, 40921062, 41072261 and 41130207）, the Special Fund for Basic Scientific Research of Central Colleges, China University of Geosciences （Wuhan_CUGL100502, G1323521132）, the 111 project （B08030） and the Opening Research Fund of State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment （SKLLQG1118）. Dr. Yangmin Qin thanks all the team of the Laboratory of Soil Biology at University of Neuchatel for inviting him visiting the laboratory and providing facilities and help.
文摘The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.
文摘对东方水韭(Isoёtes orientalis H.Liu et Q.F.Wang)2个自然样地(浙江松阳叔婆湾和小烂湖)生境土壤主要营养成分含量进行了比较分析,并对叔婆湾样地水体pH值进行了测定,在此基础上,对导致东方水韭濒危的土壤及水体因素进行了讨论。结果显示:东方水韭叔婆湾样地的土壤有机质、总氮、速效磷、速效钾和总铁离子(包括Fe3+和Fe2+)含量分别为102.7 g.kg-1、3.1 g.kg-1、18.1μg.g-1、15.0μg.g-1和221.6μg.g-1;小烂湖样地土壤中上述营养成分的含量分别为122.8 g.kg-1、4.8 g.kg-1、13.7μg.g-1、7.1μg.g-1和240.0μg.g-1。小烂湖样地土壤中有机质、总氮和速效钾含量显著或极显著高于叔婆湾样地,2个样地间速效磷和总铁离子含量差异不显著,但2个样地土壤中速效钾含量极低、总铁离子含量丰富。叔婆湾样地中上、中、下游水体的pH值分别为pH6.35、pH6.53和pH6.49,略呈中性。分析结果表明,东方水韭2个自然样地的土壤均为有机质、总氮、速效磷以及总铁离子含量较为丰富且速效钾含量较低的土壤类型,土壤中速效钾极度缺乏和水体中性化很可能是限制东方水韭种群发展的重要环境因素。
