Vitality structure of Colchicum bulbocodium subsp. versicolor (Colchicaceae, Liliopsida) populations in the Lower Volga region

Abstract

The article presents the results of the vitality structure analysis of 23 natural cenopopulations of Colchicum bulbocodium subsp. versicolor in the Lower Volga region in the years 2014–2019. The viability of cenopopulations within the studied region varied greatly over the years of monitoring, from 0.45 to 1.51. Cenopopulations in the northeast of the Lower Volga region, compared to southwestern cenopopulations, exhibited lower vitality index, greater instability and a wider range of variability of the latter parameter. Also, most morphological characters poorly correlated with one another. A high correlation was revealed only between two characters, and a medium correlation only in six pairs of characters. The largest number of significant-correlation relationships was registered for the plant height and diameter, the length and width of the lower leaf, and the length of the marigold. Based on the IQ parameter and the Q criterion, the absolute majority of cenopopulations were prosperous in all the years of monitoring. The depressive state was found only in some cenopopulations and only in certain years of monitoring (mainly in 2018). Considering that, compared to other years of monitoring, in the spring of 2018, the average temperatures during the period of the subspecies’ active vegetation and flowering were extremely low, we suggested that it could have resulted in extreme growing conditions for the subspecies in the studied region and, consequently, a decrease in vitality of cenopopulations.