Ontogenetic Structure of Cenopolulations of Orchis militaris L. and Dactylorhiza incarnata (L.) Soo (Orchidaceae, Liliopsida) in Romanovskii District of Saratov Region

Abstract

Abstract—The results of studies conducted in Romanovskii district of Saratov region during the period of mass flowering of Orchis militaris L. and Dactylorhiza incarnate (L.) Soo (June 2–16, 2017) are presented. Descriptions of the habitats of the species (a hollow and a pasture), differing in the projective cover and dominants, are given. Elytrigia repens (L.) Nevski, Carex vulpina L., and Potentilla anserina L. dominated in the hollow; Elytrigia repens (L.) Nevski, Festuca pratensis Huds., and Festuca valesiaca Gaudin dominated in the pasture. The ontogenetic structure of populations of these species is shown. In the hollow, juvenile individuals of O. militaris were absent, while immature (23.1%), verginyl (34.0%), and generative individuals (42.9%) were found. In the pasture, juvenile and immature individuals of O. militaris accounted for 6.8 and 9.3%, respectively, and verginyl (36.8%) and generative individuals (47.1%) prevailed. The age spectra of both populations are of the right-sided type. In the age spectrum of the D. incarnata cenopopulation, the proportion of age groups of the pregenerative and generative periods was 52.9%. The high recovery and efficiency indices indicate a steady status of cenopopulations of O. militaris and D. incarnate. Annual monitoring is necessary for assessing the status of the cenopopulations and forecasting their development.