Features of the stomatal apparatus can be used to assess the adaptive capabilities of alien species. Native Quercus robur L. and introduced Quercus rubra L. grow together in the arboretum of the Main Botanical Garden of the RAS and do not differ significantly in stomatal density (363.1±6.3 pcs./mm² in and Q. robur 369.8±4.7 pcs./mm² in Q. rubra), while the relative transpiration area index of Q. rubra is 1.3 times higher than that of Q. robur (20.9 % and 15.7 %, respectively). In addition, in Q. rubra it exceeds 12 %, and it can be assumed that in the future there will be an expansion of its secondary range with an increase in invasive activity.

V.V. Sokolova, V.V. Grevtsova