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

Using an architectural approach - one of the modern methods of detailed study of the structure of plants, the life form of the dwarf subshrub Thymus seravshanicus is characterized. The Species is widely distributed in different ecotopes in the Republic of Tajikistan (Hissar, Zeravshan, Hazretishokh ridges). For the first time in the structure of individuals, an architectural unit (AU) was identified and characterized, which consists of the main compound skeletal axis (n order), compound skeletal axes of the 1st (n+1) order, branching shoots and ephemeral shoots. Depending on the position of the main (n order) compound skeletal axis in space, a variety of AU was revealed: orthotropic, ascending, and mixed type. The features of their development are characterized. It is shown that in different ecological and cenotic habitat conditions, the structure of individuals is formed by repeated repetition of three or one architectural unit at the same time. In the mixed-grass steppe (black forest belt) and mixed-grass meadow (subalpine belt) communities, the structure of individuals is formed by a combination and repeated repetition of all AU. In areas with a lack of free substrate, the development of individuals begins with the formation of orthotropic AE, a dense shrub is formed; in areas of free substrate, the development of individuals begins with the formation of an ascending AE, a clump is formed. In the steppe community (juniper belt), the structure of T. seravshanicus individuals consists only of ascending AE and a clone is formed. The polyvariance of shoots development was revealed: 1) in the conditions of the black forest belt, intensive branching is characteristic for individuals, the duration of monopodial growth of shoots is up to 3 years; 2) in the conditions of the subalpine belt - rosette shoots, the duration of their monopodial growth up to 6 years; 3) in the conditions of the juniper belt in the structure of shoots there are no short metamers, the duration of monopodial growth up to 2 years. The identified features are mechanisms of adaptation of T. seravshanicus to growing conditions and do not lead to changes in the life form of the dwarf subshrub. The obtained data expand the understanding of the structure of dwarf subshrub, their morphological plasticity and serve as a basis for modeling the ways of morphological transformation of dwarf subshrub in different habitats.