Ecosystems of the Northeastern Caspian Sea Region: Spatial Pattern and Specific Features of the Plant and Soil Cover

A map of ecosystems, reflecting the spatial patterns and diversity of the soil–plant cover within the boundaries of landscape units, has been compiled for a test plot of the Caspian Lowland located at the contact of the Early Khvalyn and the Late Khvalyn sea plains. The heterogeneity of the plant and soil cover of this area is related to the microrelief, conditions of soil moisture, and soil salinity, which results in the formation of a complex pattern. The distribution of ecosystems in the Ural River valley is determined by the distance from the riverbed, the relief, and the moisture regime: groups of willow and poplar shoots are replaced by woodreed–poplar floodplain forests and forbs meadows. Vegetation undergoes anthropogenic transformation. The impact of fires is the strongest with respect to the affected area, and technogenically disturbed lands occupy a smaller area. Overgrazing areas are allocated to wells and wintering places. Regardless of the transformation factors, weedy vegetation (of annual saltwort and ephemerals) is formed in disturbed areas.