Home – Home – Jornals – Contemporary Problems of Ecology 2020 number 3

The aim of the work to present the biomorphological characteristics of ferns of the genus Athyrium Roth, occurring in South Siberia, and to identify changes of the life form during ontogenesis and in individuals of the same biological age in different ecological and coenotic conditions. Biomorphological study of plants is an important task since both the organization of populations of species and their stable existence in cenoses depend on the life form of the species. The main thing in the identification of life forms of sporophytes of ferns is the study of the formation of its perennial part, which is the rhizome. Based on the structural features of the sporophyte, we define the life form of the sporophytes of the Athyrium species living in South Siberia as summer-green polycyclic densely-rosette ferns with monopodial-dichotomously growing underground-aboveground rhizomes bearing rosette of monomorphous fronds at the apical end. The life form of the different Athyrium species is represented by two variants: (1) large-rhizome orthotropic weakly branching vegetatively non-growing monocentric ferns ( Athyrium filix-femina (L.) Roth., A. monomachii Komarov, A. sinense Rupr.), and (2) large-rhizome ascending weakly branching and weakly vegetatively growing monocentric or implicit-polycentric ferns ( A. distentifolium Tausch ex Opiz). Our study showed that the rhizomes and fronds size is increased, and the ability of rhizomes to branching is realized during sporophyte ontogenesis. The branching is dichotomous: the daughter branches are formed inside the terminal bud of the maternal branch and become distinguishable only after several years. It was determined, that rhizome remains uniaxial throughout life in sporophytes with low vitality, and rhizomes tend to branch in sporophytes with high vitality. Branching of the rhizome starts in young spore-bearing sporophytes. The largest number of branches of the rhizome, and consequently rosettes of fronds is characteristic for middle-aged spore-bearing sporophytes. At the end of the life, non-specialized disintegration (senile partitioning) occurs in the sporophytes having the branched rhizomes. This is expressed in the disintegration of the rhizome into the separate branches. According to the results of the study in various phytocenoses of the Kuznetsk Alatau, the intensity of rhizome branching in sporophytes of the same ontogenetic stage depends on environmental conditions. The rhizomes of A. filix-femina produce a large number of branches in the lighter mixed (fir-aspen and fir-birch) forests; in A. distentifolium , the intensity of the rhizome branching increases from the forest belt towards the subalpine one.