We have examined conifer samples that underwent the consequences of the Chernobyl explosion (26 April 1986) making comparisons with the Tunguska case (see paper pdf). There are similarities and differences between these two cases. Both the explosions caused defoliation due to similar mechanical and thermal effects. However, the Chernobyl catastrophe is characterized by the emission of high doses of ionizing radiations absent in Tunguska. ( See also: Figure). In the figure: the growth rings of a Chernobyl tree, wounded in 1986 by high radioactive contamination.