AGE STRUCTURE OF RHAPONTICUM SERRATULOIDES (GEORGI) BOBR. POPULATIONS. IN NORTHERN AND CENTRAL KAZAKHSTAN

The article presents the results of studying the ontogenetic structure of seven cenopopulations of Rhaponticum serratuloides in Karaganda and Akmola regions of Kazakhstan (Northern and Central Kazakhstan). The majority of surveyed cenopopulations belong to normal incomplete populations. Their ontogenetic structure has two main types of spectrum - centered two-vertex spectrum, where the maximum falls on virginal and middle-generative individuals, as well as left-sided spectrum with predominance of pre-generative individuals. The condition of cenopopulations was assessed using the "delta-omega" criterion of L. A. Zhivotovsky. According to this criterion, most of the cenopopulations are mature (CP 1-2, CP 4-5), only two (CP6 and CP7) are young. The presence of a significant number of young plants in CP6 indicates its high capacity for maintenance and self-restoration. In CP7, unfavorable conditions prevailed and potentially generative plants remained in virginile age state. CP3 occupies an intermediate position between mature and young populations. In all cenopopulations there was almost complete absence of senile and sub-senile individuals, and only in some of them - deposition of juvenile and immature individuals. Incompleteness of cenopopulations is associated with increasing anthropogenic load and narrow ecological amplitude of Rh. serratuloides.