The Great Patriotic War as a factor of florogenesis: Results of the search for polemochores in Central Russia
On the territory of Central Russia in the places of deployment of German troops, more than 45 species of plants introduced during military operations (polemochore species) have been identified. The specificity of their distribution in the regions of Central Russia is due to the mutual influence of military-historical and natural factors. The initial level of polemochore diversity was determined by the volume and composition of the imported diasporas, which depended on the duration of the occupation and the specifics of the combat operations. The greatest number of polemochore species were found in close proximity to transit nodes connecting railways with unpaved local roads and near locations of army warehouses. The main source of polemochore seeds was fodder for the horses. In addition, in some areas, grass mixtures were apparently used to mask positions. The type of plant communities, the level of landscape transformation, the nature of the economic use of the territory and the specifics of the successional dynamics of the vegetation cover were of great importance for the preservation of polemochores. Polemochores are stable in meadows, clearings and edges in light forests that are not affected by intensive economic activity and are little transformed during successional shifts. In secondary forest communities formed on the site of meadow and ruderal habitat, first of all, species with wider ecological amplitude are preserved. The vast majority of polemochores do not show a tendency to further spreading, but some species may settle outside their original habitats. In areas associated with key strategic wartime sites (for example, the Rzhev-Vyazma bridgehead), the plant community role of Central European species may be significant, and the formed communities may show similarities with Central European meadow communities. Authors mentioned reported cases of hybridization between polemochores with native species. The results obtained indicate that the Great Patriotic War became an important factor in the modern genesis of the flora of Central Russia.