The Kazan River flows through tundra and taiga, which is also known as what? 
Kazan River:  Along its course the river flows through several lakes, including Ennadai Lake and Yathkyed Lake, over the Kazan Falls (25 m ), down a red sandstone gorge and through both boreal forest and tundra. Taiga: Taiga ( ; Russian: тайга́ ; ] ; from Turkic) also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces and larches.
boreal forest