柳江流域大型底栖动物群落结构及其与水质因子的关系

The Macrobenthos Community Structure and Its Relationships with Water Quality Factors in the Liujiang River Basin

  • 摘要: 以柳江流域23个点位为例,研究了不同水文季节(3月和6月)水质因子(DO、CODMn、NH3-N、As、Hg、Cd、Pb)对底栖动物群落结构的影响,2次调查共鉴定出底栖动物4门7纲16目54科68属(种),种类相似系数为83.76%,物种丰富度表现为枯水期略高于丰水期,底栖动物优势种在枯、丰水期分别有4种和2种,具有明显的季节演替. DCA和TWINSPAN分析结果显示:柳江流域底栖动物群落结构在时空分布上存在一定差异,主要表现为枯、丰水期均有3个不同的底栖动物类群大致依次分布在该流域干流及支流的源头、中上游及下游,群落内指示物种呈现出由清洁种逐渐过渡到耐污种的变化. 指示物种分析结果(ISA)显示:在枯水期,共有8种底栖动物能作为柳江源头和大环江上游群落的指示种,分别为四节蜉属(Baetis sp.)、锯形蜉(Serratella sp.)、溪泥甲一属(Zaitzevia sp.)、短脉纹石娥属(Cheumatopsyche sp.)、蜗虫(Dugesia sp.)、朝大蚊属(Antocha)、摇蚊属(Chironomus sp.)和细蜉属(Caenis sp.),其他类群无显著指示种;在丰水期,共有5种底栖动物能作为群落划分的指示种,其中,方格短沟蜷(Semisulcospira cancellata)、钉螺(Oncomelania sp.)是柳江中上游的指示种,汉森安春蜓(Amphigomphus hansoni)、河蚬(Corbicula fluminea)、卷扁螺(Gyraulus compressus)是柳江下游的指示种. CCA分析结果显示:CODMn和DO是枯、丰水期均对柳江流域底栖动物群落分布有重要影响的水质驱动因子,而重金属因子(Cd、Pb、Hg)在枯水期对底栖动物分布影响较大, NH3-N在丰水期对底栖动物分布影响较大.

     

    Abstract: In order to study the influence of water quality factors (DO, CODMn, NH3-N, As, Hg, Cd, Pb) on macrobenthos community structure in different hydrological seasons in the Liujiang River basin, investigations were conducted in the Liujiang River basin and 4 phyla, 7 classes, 16 orders, 54 families and 68 genera (species) of macrobenthos were identified. The Czekanowsiki is 83.76% and the species richness is slightly higher in the dry season than in the wet season. There were 4 and 2 dominant species of macrobenthos in dry and wet seasons respectively, showing obvious seasonal succession. The results of TWINSPAN and DCA analysis show that there are certain differences in the temporal and spatial distribution of the macrobenthos community structure in the Liujiang River basin. In both the dry and the wet season, there are 3 different macrobenthos communities distributed respectively around the source, the upper and middle reaches and the lower reaches of the main stream and tributaries of the river. The indicator species in the community show a gradual transition from clean species to pollution-tolerant species. The results of indicator species analysis shows that, in the dry season, there are a total of 8 macrobenthos species that can be used as indicator species for the communities at the source of the Liujiang River and the upper reaches of the Dahuan River, namely Baetis sp., Serratella sp., Zaitzevia sp., Cheumatopsyche sp., Dugesia sp., Antocha, Chironomus sp. and Caenis sp., and the other communities have no significant indicator species. In the wet season, there are 5 macrobenthos species that can be used as indicator species for community division, among which Semisulcospira cancellata and Oncomelania sp. are indicator species in the middle and upper reaches of the Liujiang River and Amphigomphus hansoni, Corbicula fluminea and Gyraulus compressus are indicator species in the lower reaches of the Liujiang River. The CCA analysis results show that CODMn and DO are the water quality factors that have important effects on the macrobenthos community structure in the Liujiang River basin in the dry and wet seasons, the heavy metal factors (Cd, Pb, Hg) have a greater impact on the distribution of macrobenthos in the dry season, and NH3-N has a greater impact on the distribution of macrobenthos in the wet season.

     

/

返回文章
返回