PHLOMOIDES ALPINA (LAMIACEAE) IN THE MOUNTAIN ALTAI: MORPHOGENESIS AND POPULATION STABILITY
Elizaveta K. Komarevtseva
Central Siberian Botanical Garden SB RAS, Novosibirsk, Russia
Keywords: Phlomoides alpina, ontogeny, monopodial-rosette model of shoot formation, vegetative bud, vegetative-generative bud, Mountain Altai
Abstract
Global warming over the past few decades is causing a reduction of the area of glaciers and a rise of the upper forest line in the Mountain Altai. Therefore, it is important to study the biology of mountain species in order to determine their adaptive potential. Phlomoides alpina is one of the permanent species of subalpine communities. The study was conducted on the territory of Katun Nature Reserve (Altai Republic). Using the terms of discrete description of ontogeny, we studied the ontogeny of P. alpina and the age structure of its cenopopulation. It has been established that P. alpina is a polycarpic monopodial-rosette short-rhizome plant. Ontogeny of individuals is complete and complex with late non-specialized morphological disintegration: a mature generative individual is fragments into non-rejuvenated ramets. The species reproduction by means of seeds. The first flowering occurs at the 20-25 years age. The middle-aged generative state is the longest (25-40 years) compared to other ontogenetic states. The complete individual’s ontogeny lasts 70-90 years. Two variants of the functioning of the apical bud of the skeletal axis of the generative plant were revealed, when either vegetative-generative buds or developed vegetative buds are formed on the annual shoot. The development of vegetative-generative buds is a necessary condition for the flowering of an individual and contributes to the seed renewal of the coenopopulation. The appearance of large vegetative buds on a one-year shoot predetermines a interruptions (pauses) in flowering, but at the same time, skeletal axes are branched due to them. Due to this, multi-shoot large mature bushes are formed in the middle-aged generative state, which occupy the territory for a long time. The young normal cenopopulation of P. alpina has a left-sided multi-top ontogenetic spectrum in the subalpine meadow. The main peak on the group of juvenile individuals indicates successful seed reproduction of the species; two local peaks on virginal and mature generative individuals are associated with an increase in the duration of these states.
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