Plant Community Transformations in Desert Rangeland Ecosystems – Evidence from the North-Western Caspian Lowland

Abstract

Abstract—The article presents the results of long-term monitoring of successions, and the production dynamics in desert rangeland phytocoenoses over an 8-year period (2014–2021). It shows the current state of vegetative cover of the Chernozemelskaya sandy plain (north-west of the Caspian lowland, Republic of Kalmykia) following forest reclamation of fine-grained sands, carried out in the 1970s–1990s. The centers of soil deflation (aeolian erosion) differed by the degree of soil and vegetative cover transformation and the methods of the reclamation of open sands. Currently, a secondary vegetative cover has been formed on the previously identified deflation patches. The expansion and evolution of the current species composition suggests the development of secondary succession. The features of the synusial structure of desert phytocenoses reflect the state of plant communities. The relationship of the productivity of model pastures (shrub Callygonum aphyllum, subshrub Krascheninnikovia ceratoides, herbaceous species Stipa lessingiana, Artemisia lerchiana, Alyssum deserforum, Bromus tectorum, Carex stenophylla, Koeleria macrantha, Poa bulbosa) with precipitation in warm and cold periods of the growing season is analyzed. Under changing temporal and spatial climate dynamics, the successional processes are greatly influenced by wildfires and anthropogenic impact. It has been established that secondary successions under heavy transformation of the agro-pasture landscape develop more slowly. Thus, the natural and landscape environment of the current deflation centres in the rangelands of the North-Western Caspian region is an important factor determining the direction of succession.