PHYTOCENOTIC STRUCTURE OF PINUS BRUTIA VAR. PITYUSA (STEVEN) SILBA PLANTINGS IN THE MOUNTAINOUS CRIMEA

The studies were conducted in the places of natural growth of Pinus brutia var. pityusa (Steven) Silba in the Mountainous Crimea. In the western and eastern parts of the southern macroslope of the Main Ridge of the Crimean Mountains, in the natural boundaries of Ayazma, Batiliman, Novy Svet and on Karaul-Oba mountain sampling areas were laid, where taxational features with an assessment of the vital condition of trees were studied, and the floral composition was analyzed. The objective of the research was to assess the condition, bioecological characteristics, phytocenotic structure of natural plantings of P. brutia var. pityusa in the Mountainous Crimea, to analyze the representation of individual ecological groups of plants. As a result of the conducted research, it was found that the natural communities of P. brutia var. pityusa of the Mountainous Crimea in the coastal zone are represented in relatively limited areas. The forest understory is formed by Pistacia atlantica Desf., Juniperus deltoides R.P. Adams, Quercus pubescens Willd.; species of Cotinus coggygria Scop., Ruscus aculeatus L. and Arbutus andrachne L. have isolated occurrences. The projective cover degree of the grass tier varies between 50‒70 %. The floral composition varies from 24 to 37 species of grass tier. The differentiation of the species structure of the studied communities by types of life strategy is revealed. The western part of the distribution of plantings P. brutia var. pityusa of the Mountainous Crimea is dominated by violents and competitive stress-tolerants, while in the eastern one, explerents, stress-tolerantruderal and competitive stress-tolerant-ruderal plant species are more widespread. Based on the analysis of the level of kurtosis of the statistical distribution of species by types of life strategy, a quantitative assessment of the structure dynamics of the grass tier in the studied P. brutia var. pityusa plantings was carried out. The most significant platykurtosis of the distribution of species of different life strategies is noted in the natural boundaries of Batiliman (−2.644) and Karaul-Oba mountain (−2.513). The platykurtosis reflects a decrease in the homogeneity of the phytocenotic structure of the grass tier, which is associated with an increase in the dispersion of ecotopic conditions and an increase in successional processes. It characterizes the pattern structure of the ground cover, the formation of localities in which microstations are dominated by species that are more compliant with the specifics of multifactorial exogenous and endogenous effects. It is shown that a significant fragmentation of plantings P. brutia var. pityusa, deterioration of their condition associated with destructive anthropogenic impact, determine a decrease in the stability of species composition, desertisation of growing conditions and, as a consequence, negative changes in the floral structure of aboriginal forest communities.

var., var., plantings, condition, structure, composition, projective cover, Crimea