Suleymanova Guzyalya F. RussiaSaratovSaratov State University , 83, Astrakhanskaya str., Saratov, 410012, Russia suleymanovagf@mail.ru Author's articles Aspects’ Change of Vegetation in Khvalynsky National Park and its Preservation Zone Ecological Characteristic of Feather Grass Habitat (Stipa pennata L.) in Various Parts of the Range New Associations of Steppe Vegetation in National Park «Khvalynsky»