DYNAMICS OF PSAMMOPHYTIC STEPPE VEGETATION IN PENZA REGION WITHIN THE TERRITORY OF THE NATURAL MONUMENT "KARZHIMANTSKY SLOPES"

Abstract

The flora and vegetation of a valuable botanical object, the regional natural monument "Karzhimantsky slopes" (Shemysheysky district, Penza region), were studied. There were identified 278 species of vascular plants, including two species protected at the federal level (Iris aphylla and Stipa dasyphylla) and twelve species protected at the regional level (Adonanthe vernalis, Allium flavescens, Allium lineare, Amygdalus nana, Iris aphylla, Linum flavum, Potentilla alba, Prunella grandiflora, Spiraea crenata, Stipa borysthenica, Stipa dasyphylla, and Stipa tirsa). The following patterns of distribution of the main plant associations depending on relief and soil have been identified: turf-slag, perennial grass, annual grass and shrub true steppes develop on steep slopes of the southern and southeastern exposure and on light sandy soils, whereas turf-slag, rhizomatous, perennial grass and shrub meadow steppes develop on gentle slopes with washed-out leached chernozems. The main demutation stages of steppe vegetation that have been established proceed differently on slopes differing in their steepness and exposures. Thus, on the south and south-east steep slopes, demutation stages of psammophytic real steppes are observed: a) annuals; b) perennials; c) turf and slag; and d) shrubby; whereas on gentle slopes, demutation stages of meadow steppes are noted: a) grassland; b) rhizomatous; c) bunchgrass; and d) shrubby. The main direction of changed in the flora and vegetation of the natural monument "Karzhimantsky slopes" associated with a reduction of the anthropogenic impact over the past 20 years is, first of all, sylvatization of varying degrees, which is manifested more in meadow steppes than in true steppes.