No abstract

The main objective of this study was to quantify the diatom flora richness and analyze the diversitystructure in the aquatic habitats in Western Khentey Mountain area. During the diatom study of some streams andrivers namely Barchuluut, Huder, Ichleg, Shariin gol, and Sharlan rivers, which are located in western part of Khenteymountains, 98 species of diatoms were registered and the result compared with literature sources. In the water bodies inthe western part of Khentey mountains totally 673 species and subspecies of algae were registered (Bacillariophyceae(640), Coscinodiscophyceae (20), Mediophyceae (13)). They represent 35 percent of Mongolian algae flora.

We analyzed the distribution area of the threatened algal species concerning Mongolia's nationally and internationally protected areas, using Geographic Information Systems analysis. Approximately 63% of the total at-risk species have distributions that partially overlap state special protected areas. I determine that 24.3% of the rare and endangered species are in Strictly Protected Areas, 43.9% are in National Parks, 4.8% are in Nature Reserves, and 2.4% are in Natural and Historical Monuments. Habitats for fi fteen species of rare and endangered algae are not even partially protected, although four of those species are found in internationally conserved areas. We propose to study in detail the biology, ecology, and distribution of Chara gobiana and Oedogonium itzigsohnii and to consider some lakes such as Buir, Khukh and Taatsyn Tsagaan be included under special protection state to protect critical habitats for Mongolia's rare and endangered algae.

This study is the first of its kind in Mongolia to make an ecological health assessment of birch forest, based on the composition of soil algae species. The Chlorophyta consisted of 54.5 percent of the total algae species. In Jargalant-Tain pass, Bogdkhan Mountain, the ground of the birch forest is drying up. Deterioration of forest soil ecology and the onset of aridity indicate the process of deforestation. Therefore, reforestation is urgently needed.