The ontogeny and the demographic structure of the coenopopulations of the species Oxytropis chakassiensis (Fabacaea) in the steppe communities of Khakhassia (Russian Federation)

Inessa Selyutina,Svetlana Lebedeva,Evgeny Zibzeev,N.N Lashinsky,N.I Makunina

doi:10.1051/bioconf/20191600031

Abstract

The article presents the results of the analysis of the demographic structure of ten coenotic populations of Oxytropis chakassiensis in near-Yenissei steppes (Khakassia and Krasnoyarsk krai). Most part of studied species coenopopulations are not complete and definitive, normal, mature, have a bimodal developmental spectrum with peaks at g1 (v)- and g3-individuals. Changes in the structure of the ontogenetic spectrum (increasing the share of young plants) depend mainly on the environmental conditions and the degree of human disturbance of habitats: rocky slopes and decrease in pasture digression create more favorable conditions for the survival of juveniles. The ontogeny of O. chakassiensis (the rare species of near-Yenissei steppes) was studied and its life- form was described. Four periods and nine ontogenic stages were distinguished. The results of our study showed that O. chakassiensisis was a petrophyte steppe species with strict ecological and cenotic propensity to petrophytic steppe with the prevalence Koeleria cristata, Festuca valesiaca, Arctogeron gramineum, Hedysarum turczaninovii, Alyssum obovatum and Thymus minussinensis. Due to long generative period O. chakassiensis is successfully renewed and is stable during long periods of extreme conditions of petrophytic steppes with high pasture digression.

Highlights

It is well-known that, in order to evaluate the state and the possibility of preservation of rare species, it is necessary to study their biological characteristics and the structure of their populations
O. chakassiensis Polozhij is a rare species, endemic of the near-Yenissei steppes, which is registered in the Red Books of the Republic of
Khakassia [4] and of the Krasnoyarsk krai [5]. It is protected in the Khakasskiy reserve in the areas of Lake Itkul and Lake Bele

Summary

Introduction

It is well-known that, in order to evaluate the state and the possibility of preservation of rare species, it is necessary to study their biological characteristics and the structure of their populations. The ontogeny and the demographic structure of ten (10) coenotic populations (CP) of O. chakassiensis were studied in the steppe regions of the Republic of Khakassia. To identify the ontogenetic states of the plants, we used the following features: the presence of cotyledons, the structure of leaves and their number, formation of a caudex, the ratio of the processes of growth and destruction and the number of vegetative and generative shoots.

Results

Conclusion