This article reviewed studies from Germany, Russia, Lithuania, Sweden and Finland about wolf trees in Scots pine (Pinus sylvestris L.) forests and examined the definition of a wolf tree. In addition, we analyzed the main traits and parameters of these trees, such as lower crown ratio, more conical stem taper, partly deformed crown, and thicker and longer branches. The analysis revealed changes in the definition of a wolf tree during the XX century and different definitions over various regions. The differences between wolf trees and common trees were found in growth patterns, stress sensitivity and genetics. Also this article reviewed several possible reasons for the occurrence of wolf trees in forest stands.

Keywords: b-type trees, tree development, morphological types, competition, crown form, growth patterns, thinning.