[Responses of the Benthic Diatom Community to Nutrients and the Identification of Nutrient Thresholds in Three Aquatic Ecoregions of the Huntai River, Northeast China].

Benthic diatom communities and nutrient gradients were investigated from 287 sampling sites in three aquatic ecoregions (AE) of the Huntai River to characterize the spatial distribution of nutrients and the benthic diatom communities. Locally weighted scatterplot smoothing (LOWESS) was used to analyze the thresholds for nitrogen and phosphorus. The results showed that:① The concentration of ammonia nitrogen and total phosphorus significantly differs in the three AEs, and shows a tendency of AEⅠ < AE Ⅱ < AE Ⅲ.

[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.

[Community Structure Characteristics of Eukaryotic Planktonic Algae in Liaohe River Through High-throughput Sequencing].

Eukaryotic phytoplankton plays an important ecological function in river ecosystem. The 18S rRNA gene V4 variable region of the environmental samples in Liaohe river was sequenced by using 454 pyrosequencing technology. The reprehensive sequences of OTUs were annotated, and then the OTUs list was compared to the species list obtained by microscope observation.