生物完整性指数(Index of biotic integrity,IBI)被广泛运用于河流的健康评价.然而,随着人类活动对河流影响的增加,传统指示生物多样性的损失降低了评价的准确性.在高度受影响的水体环境中,微生物群落被证明是更敏感的生态健康指标.本...生物完整性指数(Index of biotic integrity,IBI)被广泛运用于河流的健康评价.然而,随着人类活动对河流影响的增加,传统指示生物多样性的损失降低了评价的准确性.在高度受影响的水体环境中,微生物群落被证明是更敏感的生态健康指标.本研究采用Illumina高通量测序技术,于2018年冬季和2019年春季对无锡市境内8条河流的微生物群落组成进行了分析,从群落组成/相对丰度、丰富度/多样性、敏感性/耐受性3个角度确定了候选指标.并对传统的核心指标筛选方法进行了改进,通过差异性分析、箱线图检验、Speraman相关性分析,建立了冬、春两季的微生物生物完整性指标框架.评价结果表明,M-IBI能有效区分不同程度的受损位点,且与水质状况和物理生境存在显著的相关性.总体而言,M-IBI为城市河流生态状况提供了一种新的评价工具.展开更多
The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and ...The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.展开更多
文摘生物完整性指数(Index of biotic integrity,IBI)被广泛运用于河流的健康评价.然而,随着人类活动对河流影响的增加,传统指示生物多样性的损失降低了评价的准确性.在高度受影响的水体环境中,微生物群落被证明是更敏感的生态健康指标.本研究采用Illumina高通量测序技术,于2018年冬季和2019年春季对无锡市境内8条河流的微生物群落组成进行了分析,从群落组成/相对丰度、丰富度/多样性、敏感性/耐受性3个角度确定了候选指标.并对传统的核心指标筛选方法进行了改进,通过差异性分析、箱线图检验、Speraman相关性分析,建立了冬、春两季的微生物生物完整性指标框架.评价结果表明,M-IBI能有效区分不同程度的受损位点,且与水质状况和物理生境存在显著的相关性.总体而言,M-IBI为城市河流生态状况提供了一种新的评价工具.
基金supported by the National Natural Science Foundation of China(Grant Nos.41172163,40972116)the Chinese National Programs for Fundamental Research and Development(Grant No.2010CB950202)+1 种基金the program for New Century Excellent Talents in University(Grant No.NCET-12-0251)the Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2013-K17)
文摘The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.
