Analysis of the current status of populations of rare plant species of nature monument Troicki chalk mountains (Orenburg region)

Abstract

the results are presented for the study of four rare species in the Troicki chalk mountains: Anthemis trotzkiana Claus., Matthiola fragrans Bunge, Lepidium meyeri Claus, and Zygophyllum pinnatum Cham. The total density of the studied coenopopulations ranged from 2.2 to 6.1 copies/m², and the effective density was 1.5–4.2 copies/m². Coenopopulations are normally incomplete, most typically lacking the spectrum of seedlings, juvenile and senile individuals, and generative individuals that peak in middle-age. Coenopopulations Anthemis trotzkiana lack postsenile individuals. By the “delta-omega” classification, coenopopulations Anthemis trotzkiana, Matthiola fragrans are growing old, Lepidium meyeri are transitional, and Zygophyllum pinnatum are mature. The indices of recovery and senescence are 0.03–0.36 and 0.03–0.72, respectively. High levels of variability and plasticity of morphometric characters have been registered.