阿什河流域底栖硅藻群落特征及水环境健康评价

为探索黑龙江省阿什河流域底栖硅藻群落特征及环境相关性,并对阿什河流域进行水环境健康评价,本研究于2018年7月(丰水期)和2018年10月(枯水期)对阿什河流域8个典型采样点进行调查。基于相似性分析检验(analysisofsimilarities,ANOSIM)和相似百分比分析(similarity percentages,SIMPER)分析探索枯水期与丰水期之间底栖硅藻的群落差异,通过冗余分析(redundancyanalysis,RDA)对驱动底栖硅藻的关键环境因子进行筛选;使用硅藻生物指数(biological diatom index, IBD)、硅藻属指数(generic index of diatom, GI)和水体营养指数(trophic state index, TSI)对研究区域水体营养状态进行初步评价。结果表明,研究期间共鉴定底栖硅藻89种,其中丰水期80种、枯水期57种。独立样本T检验(T-test)表明阿什河流域物种丰富度丰水期显著高于枯水期(P0.05),Shannon-wiener指数变化不显著(P0.05)。ANOSIM结合SIMPER分析结果显示阿什河流域硅藻群落格局存在一定的时空异质性。RDA分析表明水的电导率是驱动阿什河流域底栖硅藻空间分布的环境因子,枯水期与丰水期之间高锰酸盐指数(COD_(Mn))含量的变化是影响硅藻群落演替的因素之一。IBD、GI和TSI指数结果显示阿什河流域受人为活动干扰区域营养状态较差, IBD指数较GI指数能更有效的反映阿什河流域水体营养状况。

Benthic Diatom Community Characteristics in Ashi River Basin and Aquatic ENVIRONMENTAL Health Assessment

The characteristics of benthic diatom communities and their response to the environment in the Ashi River Basin, Heilongjiang, NE China were explored, and the health state of water was evaluated. Eight typical sampling sites of the basin were investigated in wet season (July 2018) and dry season (October 2018). The differences of benthic diatom communities between the two seasons were studied by the analysis of similarities (ANOSIM) and the similarity percentages (SIMPER). The key environmental factors driving benthic diatoms were specified by RDA (redundancy analysis). The water trophic status of the area was determined using IBD (biological diatom index), GI (generic index of diatom), and TSI (trophic state index). Results show that there were a total of 89 taxa, of which 80 species in wet season and 57 species in dry season were identified. The richness of the wet season was significantly higher than the dry season (P<0.05), while there was no significant change in Shannon-Wiener index among different seasons (P>0.05) as indicated in the independent sample T-test. In addition, the spatial and temporal heterogeneity was certain in the diatom community patterns in the area as revealed in ANOSIM and SIMPER. Water conductivity was found the driving factor on the spatial distribution of benthic diatoms in the Ashi River Basin as confirmed in RDA, and the change of COD_Mn between the seasons was one of the factors contributing to the succession of diatom communities. Overall, the nutritional status of Ashe River Basin was poor as shown by IBD, GI, and TSI, of which IBD index was more effective than GI index.