The living state of woody plants having different levels of thermal damages in the summer of 2010 was studied. It is shown that a number of species had partial drying out and the death of trees unevenly in plantations of different age and localities. In a favourable ecological environment they remained healthy. They are mesophytes and mesohygrophytes which are on the southern border of the areas, mostly explerents. The trees and shrubs of floodplain forests and certain introducents are tolerant of a thermal stress.