Soil and Vegetation Heterogeneity in Postagrogenic Restorative Succession in the Middle Taiga Subzone

The specific features of the soil–vegetation heterogeneity at the early stages of restorative succession have been studied. These features are determined by biotic and bioinert conditions that were influenced by anthropogenic factors during long-term plowing on azonal carbonated soils in the middle taiga subzone (Kargopol district, Arkhangelsk Oblast, Russia). In total, 25 full-profile soil sections, 500 soil samples, 125 sites for counting tree and shrub species, 25 standard geobotanical plots, and 250 plots for counting herbaceous species have been studied and analyzed. During the first 15 years of restorative succession on fallow agricultural land, herbaceous vegetation has the highest phytocenotic significance. On the residual calcareous soils of the forest zone, the specialization of ecological properties, i.e., the confinement of species to certain factors is weakly pronounced only in some herbaceous species. The mosaic structure of vegetation cover on a 15-year-old fallow is determined not by the variability of soil properties and the influence of growing tree and shrub species, but by the biological properties of herbaceous plants and their specific requirements for environmental factors. Soil fertility and soil moisture are the main factors that determine the variations of vegetation at this stage.