ИСТИНА

Aim: to assess a biota modern dynamic near the northern edge of the distribution of steppe ecosystems. Location: Central Russian plain, Tul’skaya, Moskovskaya, Ryazanskaya Oblast’s. Methods: Field observations on vascular plant, insect, and bird distribution; retrospective analysis of land cover, vegetation cover, and distribution of plant and animal species (using field data, remote sensing, and historical maps). Results. Over the last century, the northern edge of the forest-steppe zone is stable. To the north of this zone, broad-leaved forests after logging are often replaced by self-replicating small-leaved forests, usually existing as small groves with a small number of broad-leaved trees. Many birds, especially birds of prey, have become rare. Some insect and plant species have spread to the north of the forest-steppe belt in small extrazonal steppe sites. New extrazonal steppe sites have not been identified. We assume that the broad-leaved forests have degraded both due to the leveling of the canopy in the cutting areas, and due to the reduction in the size of the groves, which leads to the drying of the microclimate. Global warming has increased this effect. At the same time, despite the warming and drying up of the climate, the steppe ecosystems do not extend to the north, because there are no corresponding soils there. Reducing the number of birds of prey reduces their role in ecosystems. As a result, at the belt to the north of the forest-steppe zone, when climate changes, an azonal biota is formed with a reduced ability to self-regulation.