On the issue of branch structure of temperate zone trees within the context of ontogeny

Incertain definition of «tree», «crown» and «branch» terms causes further investigations necessity. This article deals with «branch on the trunk» as important unit of tree crown structure, which is a naturally detached item in tree crown. It is formed on the base of morphogenetic correlations system as a result of the species ontogenetic development program. Thus branch diversity in crown is determined. A tree has different types of branches on the trunk in any ontogenetic stage. Tree crown form transformation during ontogeny is induced by alteration in the set of branch types. The most of temperate trees species have branch types maximum variety while virginal and young reproductive ontogenetic stages are lasting. Branch diversity decreases abruptly in old reproductive stage. The taxa differ in branch on the trunk structure and variety. The tree species, which are similar in light condition requirements also quite resemble in ways of the tree crown transformation. Similarities and differences of branch on the trunk diversity is a promising issue for life form investigations.