Architectural types of plants in cenopopulations of Erophila verna (L.) Besser. (Brassicaeae ) in the ecotone system "water-land" on the coast of Chograysky reservoir

The article presents the results of a study of cenopopulations of Erophila verna in the vegetation communities of the “water-land” ecotone system on the coast of Chograysky reservoir, located on the border of Kalmykia and Stavropol Krai. The structural and functional organization of the “water-land” ecotonic system of the coast in question is characterized in terms of its four separate blocks: fluctuational, dynamic, distant and marginal. Each of the structural blocks of the ecotonic system is represented by a certain plant community. The fluctuational block of the ecotone system includes two separate zones; in the second zone, the more distant from the water’s edge, Tamarix ramosissima - Artemisia santonica community grew on wet meadow strongly saline soils. In the dynamic block a community T. ramosissima - A. santonica was formed on almost non-saline meadow soils. The distant block consisted of two zones. The vegetation of the first zone was represented by Artemisia santonica, A. austriaca - Poaceta and Artemisia santonica, A. austriaca - Poa bulbosa communities. The vegetation of the second zone was represented by Artemisia taurica, A. austriaca - Poa bulbosa community with the Anabasis growing on meadow-chestnut non-saline soils. In the marginal block there was Artemisia austriaca community growing on meadow-chestnut, non-saline soils. The cenopopulations of Erophila verna examined in different structural blocks of the ecotone system of Chograysky reservoir showed specific density characteristics. Cenopopulations of E. verna 1 and 2, which were growing in the fluctuational and dynamic blocks of the ecotone, were characterized in terms of individual plants’ growth by three architectural variants, including plants of one-, two - and three shoots; one-shoot plants showing the biggest frequency (from 58.1% to 83.1%). Cenopopulation 3 showed a decreasing frequency of plants of one to six shoots. Finally, cenopopulation 4 was characterized by a decreasing frequency of one to five shoot plants; also, there were eight shoot plants with a frequency of 0.6%.