Qiu Linlin, Cui Hongyang, Wu Junqiu, Wang Baijie, Zhao Yue, Li Jiming, Jia Liming, Wei Zimin
College of Life Science, Northeast Agricultural University, Harbin 150030, China.
College of Life Science, Northeast Agricultural University, Harbin 150030, China.
Sci Total Environ. 2016 Jun 15;556:242-51. doi: 10.1016/j.scitotenv.2016.02.199. Epub 2016 Mar 11.
Bacterioplankton plays a significant role in the circulation of materials and ecosystem function in the biosphere. Dissolved organic matter (DOM) from dead plant material and surface soil leaches into water bodies when snow melts. In our study, water samples from nine sampling sites along the Heilongjiang watershed were collected in February and June 2014 during which period snowmelt occurred. The goal of this study was to characterize changes in DOM and bacterioplankton community composition (BCC) associated with snowmelt, the effects of DOM, environmental and geographical factors on the distribution of BCC and interactions of aquatic bacterioplankton populations with different sources of DOM in the Heilongjiang watershed. BCC was measured by denaturing gradient gel electrophoresis (DGGE). DOM was measured by excitation-emission matrix (EEM) fluorescence spectroscopy. Bacterioplankton exhibited a distinct seasonal change in community composition due to snowmelt at all sampling points except for EG. Redundancy analysis (RDA) indicated that BCC was more closely related to DOM (Components 1 and 4, dissolved organic carbon, biochemical oxygen demand and chlorophyll a) and environmental factors (water temperature and nitrate nitrogen) than geographical factors. Furthermore, DOM had a greater impact on BCC than environmental factors (29.80 vs. 15.90% of the variation). Overall, spring snowmelt played an important role in altering the quality and quantity of DOM and BCC in the Heilongjiang watershed.
浮游细菌在生物圈的物质循环和生态系统功能中发挥着重要作用。当积雪融化时，来自死亡植物材料和表层土壤的溶解有机物（DOM）会渗入水体。在我们的研究中，于2014年2月和6月沿着黑龙江流域的9个采样点采集了水样，这期间发生了融雪。本研究的目的是描述与融雪相关的DOM和浮游细菌群落组成（BCC）的变化、DOM、环境和地理因素对黑龙江流域BCC分布的影响以及水生浮游细菌种群与不同来源DOM的相互作用。通过变性梯度凝胶电泳（DGGE）测定BCC。通过激发-发射矩阵（EEM）荧光光谱法测定DOM。除了EG之外，所有采样点的浮游细菌群落组成因融雪而呈现出明显的季节变化。冗余分析（RDA）表明，BCC与DOM（成分1和4、溶解有机碳、生化需氧量和叶绿素a）以及环境因素（水温、硝酸盐氮）的关系比与地理因素更为密切。此外，DOM对BCC的影响大于环境因素（变异的29.80%对15.90%）。总体而言，春季融雪在改变黑龙江流域DOM的质量和数量以及BCC方面发挥了重要作用。
