浑河流域底质类型对硅藻群落分布特征的影响

河流底质可以为硅藻提供附着的基质,不同的底质类型对硅藻群落结构有一定的影响.本研究对浑河流域上23个采样点位进行调查研究,并运用多响应置换过程、典范对应性分析、线性回归分析等,分析河流底质类型对硅藻群落的影响.多响应置换过程结果显示,苏子河、红河和英额河、浑河中游及浑河下游水系之间硅藻群落空间差异显著;香农多样性指数、均匀度指数与物种丰富度的平均值分别为2.57、0.69和15;典范对应性分析结果显示,IOS指数、电导率、总氮和总磷是显著影响硅藻群落结构的环境因子;相关分析结果显示,香农多样性指数、均匀度指数和物种丰富度与IOS指数呈正相关.本研究中,河流底质类型为大石块、鹅卵石等类型时,硅藻多样性较高;而底质类型为淤泥和细沙时,硅藻多样性较低.

Effect of sediment type on the distribution of diatom community in Hunhe River Basin, China

The sediments of river can provide ground substance for diatom. We investigated 23 sites of Hunhe River to analyze the effect of different types of ground substance on diatom community. Diatom community and types of sediments were evaluated with the multi response permutation procedures analysis, canonical correspondence analysis and linear regression analysis. Results of multi-response permutation procedures analysis showed that there were obvious space differences of diatom communities among the Suzi River, Hong River, Yinge River and the midstream of the Hun River and the downstream of the Hun River. The index of Shannon diversity, evenness index and species richness were 2.57, 0.69 and 15, respectively. Results of Canonical correspondence analysis show that IOS index, conductivity, total nitrogen and total phosphorus were the key environmental factors that affected diatom community structure. The results of linear regression analysis show that Shannon diversity index, evenness index and species richness were positively correlated with IOS index. Our results indicated that the diversity of diatom will be higher when the sediment contains large boulders and pebbles, but lower for the semdiments with silt and fine sand.