Russian Journal of Ecosystem Ecology (Jan 2023)
STRUCTURE OF THE PRAIRIE WILLOW CROWN OF DIFFERENT LIFE FORMS
Abstract
Background. Boreal species of willows have not yet been sufficiently studied from the standpoint of ontogeny and the structural and functional organization of the crowns of adult individuals. The formation of the structural and functional organization of S. starkeana individuals of various life forms is analyzed from the standpoint of the concept of modular plant organization, architectural models, and the concept of the crown organization plan. Materials and methods. To identify ontogenetic states, a generally recognized classification was used. The classification of shoots and shoot systems of the crown is based on three features: the length of the internodes that make up the shoot; shoot age; the presence of branching. Architectural module is highlighted in accordance with the previously developed methodology. Results and conclusions. In a detailed study of the ontogenesis of the prairie willow, it was found that it is characterized by morphological polyvariance of development, as a result of which four life forms are formed in the adult state: epigeogenic-geoxyl and hypogeogenic-geoxyl shrub, tree, low long-xylorizome hypogeogenic-geoxyl shrub. They grow in different ecological conditions and differ in different qualitative and quantitative characteristics. Modules were identified in the crown of the prairie willow: 1 – metamer, 2 – uniaxial shoot, 3 – three-year shoot system (architectural module), 4 – branch from the trunk, 5 – crown as a whole. As part of the crown, seven main variants of vegetative shoots and two-stage-falling vegetative- generative shoots were studied.As part of the one-year vegetative shoot, seven variants of metamers were identified, differing structurally and functionally. As the main structural unit of the shoot system, a three-year shoot system was singled out, and on its basis, taking into account three features, an architectural module was selected. When singling out the types of three-year shoot systems, a correlation was made between the hierarchical and polyarchic constructive plans for the organization of the crown. In the course of the work, it was revealed that the architectural modules have gender differences, manifested in a greater degree of branching and a greater number of one-year assimilating shoots in females, which is due to the predominance of their polyarchic organization plan.
Keywords
