Floristic core of the Russian Plain pine forests along Pinus sylvestris southern borders

Pine forests - forest tracts on the sandy left banks, where the main area is occupied by plant communities with a predominance of Pinus sylvestris . Due to the significant distance from each other, the floras of the pine forests differ. However, the flora of these pine forests also shares common characteristics. In order to establish the floristic unity of the forests at the southern limit of the distribution of Pinus sylvestris , work was carried out to identify their floristic core. For 20 years, floristic surveys have been carried out in the forests of the steppe and forest-steppe zones. A general floristic list was compiled, with the identification of aboriginal and alien fractions, and the floristic core was established. Revealed: the core of the flora is determined by the pine forest flora with the lowest number of species among the comparable pine forests. The core of the flora of the studied pine forests included 30.8% of the species of the general flora. An increase in the number of analyzed floras will bring accuracy to the determination of the floristic core. This will make it possible to form an understanding of the pine forest flora as a single floristic complex.