Spatial structure of Iris pumila L. cenopopulations in the Volgograd region

Abstract

One of the modern environmental problems is the reduction in the number of rare plant species due to an increase in anthropogenic pressure on natural phytocenoses. Cenopopulation studies of Iris pumila L. will make it possible to study the real state of natural coenopopulations, which is the result of the intrapopulation distribution of individuals. This article is devoted to the issue of the spatial structure of Iris pumila populations in the Volgograd region. The studies were carried out in 25 coenotic populations within the Volgograd region at 11 geographical points. The total area of surveyed populations was about 923,000 m2. The article discusses the main distribution types of a rare species individuals in natural populations, and also gives their characteristics. Ecological and coenotic studies of a rare species at the regional level are presented. The life cycles of Iris pumila have been determined. The data on the vitality structure of the Iris pumila cenopopulation are given, the ratio of individuals of different levels of vitality in the population is an important characteristic, which gives an assessment of the level of population viability in specific habitat conditions. The average density of generative individuals in the population is 92.6 pcs/m2. The number of individuals of Iris pumila in most local populations is stable. Reproduction of plants and renewal of individuals is quite stable. Under the influence of anthropogenic activity, individuals in populations age, and renewal decreases. At present, the studied cenopopulations are in stable good condition.