State of coenopopulations of Dactylorhiza maculata (L.) Soo. (Orchidaceae Juss.) in disturbed habitats of the Arctic urbanized territory

Abstract

The paper presents results of studying of coenopopulations of the orchid Dactylorhiza maculata in disturbed habitats of the Arctic urbanized territory. D. maculata has an International Protection rank: the species is included in the IUCN Red Data Book, in Application II to the International CITES Convention. The study of coenopopulations was carried out in the city of Murmansk (68o 58' N; 33°05' E) along the St. Petersburg - Murmansk highway on permanent and temporary test sites. According to the contamination of biotopes by petroleum products and vehicle emissions, the experimental sites were divided into two groups: with high and medium pollution. On heavily polluted wetlands and roadsides, a very high density of orchids was revealed, from 118 to 127 (plants/m2). The ontogenetic spectrum of coenopopulations of D. maculata is left-sided, with a predominance of plants of the pregenerative period (73 - 82%), a "renewal wave" is noted. The share of seedlings, juvenile and immature plants is high. Among age groups, the proportion of blossoming plants of the generative period varies from 18 to 27%. In biotopes with medium level of pollution of environment, the density of D. maculata coenopopulations is much lower (21–27 plants/m2). The high size and density of coenopopulations, germination of seeds under the conditions of environmental pollution by petroleum products and vehicle emissions, the presence of all age states in the ontogenetic spectra, except for senile ones, indicates a high ecological lability of D. maculata. This species can be attributed to the “early colonizers” of disturbed habitats and be used for bioindication of the level of their environmental pollution.