Nurzhaugan I. Duisenova, Akzhunis A. Imanbayeva and Margarita Y. Ishmuratova
Abstract
The purpose of this work was to study the structure of populations of hawthorn (Crataegus ambigua) in their natural habitats - Mangistau region (the gorges of Samal, Ackmysh, Sultan Epe, Karakosayim, Kesim, Jamsemsai). The results of the research allowed determining that the Crataegus ambigua occupied the upper shrub layer, and was the dominant or codominant with the total projective cover of 40-80%, and with species composition from 30 to 55 species. The habitat of the species is confined to the lower parts of the gorges with the presence of fresh water. The age structure of populations in the gorge Ackmysh were characterized as a young developing and with a dominance of pregenerative individuals. In the gorges Samal, Sultan Epe, Karakosayim populations of Crataegus ambigua were middle-aged, sustainable, and with a domination of generative individuals and a sufficient amount of regrowth for a sustainable reproduction. The age range in gorge Jamsemsai was characterized as unstable ageing with a predominance of generative individuals, but minor undergrowth. The vitality of the plants ranged from 1 to 2 points. Were identified 3 types of Crataegus ambigua life forms - trees, shrub-arboreal forms, shrubs. The share of trees accounts for 15.2 % of specimens, shrub-arboreal forms 70,9 %, the share of shrub is 13.8 %.