Role of latent buds in crown architecture in coniferous and deciduous trees of the temperate zone
M. V. Kostina1, N. S. Barabanshchikova1, O. I. Yasinskaya2
1Moscow Pedagogical State University, Moscow, Russia
2Tsytsin Main Moscow Botanical Garden of RAS, Moscow, Russia
Keywords: деревья, крона, архитектурная модель, скелетные оси, ветви, реитерационные комплексы, спящие почки, trees, crown, architectural model, skeletal axis, branches, reiterated complexes, latent buds
Abstract
The study was aimed to investigate the latent buds localization and the characteristics of the structures arising from the buds in conifers and deciduous trees in response to age-related changes and various growing conditions. The crown analysis was performed using architectural models and reiteration concept. It was found that in deciduous trees, the latent buds were usually at the bases of annual growth, and in conifers the latent buds were at the bases of annual growth, in the bud scales axils, or along the entire length of the shoot in the needle axils and in the shoot’s distal part. It was revealed that the short shoots’ terminal buds could function as latent buds. In deciduous trees, the skeletal axes’ natural aging is the endogenous factor of shoots’ development from latent buds. In evergreen conifers it is the plant’s response to the needles’ aging. This leads to the growth induction of latent buds and to the acropetal appearance of the buds on the mother axis in conifers. In deciduous trees, the reiterated complexes form in response to the axis development cycle completion, which causes the initiation of latent buds in the centripetal direction. In conifers, the reiterated complexes look like bundles: such structures form due to the latent buds’ easy initiation, which leads to the formation of the other orders’ shoots. In deciduous trees, the reiterated complexes are characterized by prolonged growth, acrotonic branching mode and orthotropic growth direction. In deciduous trees, the crown of the old generative and senile plants almost entirely consists of reiterated complexes. It has been found that conifers have a different degree of latent buds participation in the crown formation, which can vary significantly within the same genus. In Picea abies (L.) Karst., the reiterated complexes replace small twigs. In some other species (for example, Picea schrenkiana Fisch. et E. Mey., Abies sibirica Ledeb., Pinus sibirica Du Tour.), the reiterated complexes can also replace the extending from the trunk skeletal branches. In Pinus sylvestris L., no secondary crown is formed.
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