滑石矿开采对着生藻群落结构和水环境的影响

为了解滑石矿开采对河流水生态环境的影响,分别于2015年11月、2016年4月和2016年7月这3个时期对汤河(太子河重要支流)上游6个监测断面(TH01~TH02为参照河段,TH03~TH04为受损河段,TH05~TH06为恢复河段)的水质状况和着生藻群落进行了调查分析.利用Mann-Whitney U检验分析比较了各河段水环境因子和着生藻群落结构组成的差异;利用Spearman相关性分析、典范对应分析(canonical correspondence analysis)和t值双标图(t value biplot)分析水环境因子与着生藻群落结构的相互关系.结果表明:(1)与参照河段和恢复河段相比,受损河段的Mg、Se、As、Fe、Mo、EC、HCO-3、NO-3和p H均值最高.其中,Mg、Mo、As、EC、HCO-3在受损河段与其他河段间存在显著差异(P0.05).(2)与其他河段相比,受损河段的着生藻密度、物种丰富度、具柄硅藻百分比、曲壳藻属(Achnanthes sp.)相对丰度均最小,可运动硅藻百分比、双菱藻属(Surirella sp.)相对丰度和舟形藻属(Navicula sp.)相对丰度最大,其中物种丰富度在受损河段与其他河段间存在显著差异(P0.05).(3)EC、HCO-3和Mg对研究区域的着生藻群落结构有显著影响,且均与物种丰富度、具柄硅藻百分比显著相关(P0.05).

Impact of Talc Ore Mining on Periphyton Community Structure and Water Environment

In order to explore the impact of Talc ore mining on aquatic ecosystems, periphyton communities and environmental factors from control portion, impacted portion and recovery portion separately were investigated and analyzed. Samples were collected from upstream Tanghe River (an important tributary of Tazi River) in November 2015, April 2016, and July 2016. Mann-Whitney U test was applied to compare the differences in environmental factors and periphyton community structures among three portions. Spearman correlation analysis, canonical correspondence analysis, and t-value biplot analysis were used to determine the relationship between the environmental factors and periphyton community structures. In the control and recovery portions, mass concentrations of magnesium (Mg), selenium (Se), arsenic (As), iron (Fe), molybdenum (Mo), bicarbonate ion (HCO₃^-), nitrate ion (NO₃^-), power of hydrogen (pH) and electric conductivity (EC), were the highest, and in the impacted portion, mass concentrations of potassium(K), sodium (Na), strontium (Sr), barium (Ba), silicon dioxide (SiO₂), and dissolved oxygen (DO) were the lowest. The mass concentrations of Mg, Mo, As, EC, and HCO₃^- were significantly different (P<0.05) among the three portions. In control and recovery portions, the periphyton density, species richness, diatom siltation index, and relative abundance of Achnanthes sp. were the highest, while in the impacted portion, the percentage of handle diatom, the relative abundance of Surirella sp., and relative abundance of Navicula sp. were the lowest. Species richness of periphyton was significantly different (P<0.05) among the three portions. In summary, Mg, EC, and HCO₃^- from Talc Ore mining had significant impacts on periphyton assemblage structure.