Diatom Richness in the Temporal and Spatial Variability of Biotopes in Khara River Catchment, Mongolia

This investigation aimed to assess the diatom diversity, richness, and occurrence for each biotope temporal and spatial variability along the Khara River basin, Mongolia. We collected diatom samples in 19 sites across the Khara River basin every three years for the May and August months. Three hundred thirty-six species of diatoms were recorded in this basin, and 24.4 percent or common species of those occurred on all three biotopes. After the inflow of small tributary rivers into the main river, the species wealth increases from the previous point in the main river. The number of species at the upper reaches is not much, and the Shannon diversity is high, while at the down reaches is opposite. During May, the highest number of species occurred on epipelon, while the highest diatom number occurred on epiphyton during August. This diatom investigation is the first of the Khara River in Mongolia.