КОРРЕЛЯЦИЯ ПАРАМЕТРОВ ЛИСТОВОГО АППАРАТА ТОПОЛЕЙ В УСЛОВИЯХ ГОРОДСКИХ ПОСАДОК

Abstract

The parameters of the leaf apparatus of reproductively mature trees of five species from different sections of the poplar genus, most frequently encountered in urban plantings of Nizhny Novgorod, are investigated. Chinese poplar (Populus Simonii Carr.), white poplar (Populus alba L.), laurel poplar (Populus laurifolia Ledeb.), black poplar (Populus nigra L.), balsampoplar (Populus balsamifera L.). The methodological basis of the study was based on the principles of the only logical difference, suitability and expediency of the experiment. Along with the signs of direct account in the scheme of the experiment, derivative features are introduced that give a quantitative evaluation of the shape and an indirect estimate of the area of leaf blades. Statistical, correlation and regression analysis were used according to the generally accepted schemes. Representatives of the poplar genus in the urban plantations of the Middle Volga region form a leaf apparatus, that exhibits a variability in the basic morphological characteristics. Varying the linear parameters corresponds to the low and medium level of the Mamaev scale, which was steadily manifested in all the species studied. The coefficients of variation in the length of the leaf blade were from 12.05% (P. laurifolia) to 20.85% (P. alba). Correlation of the length and width of the leaf blades corresponds to the high closeness of the Cheddock connection, and their connection with estimates of the area of the leaf surface is very high and fixed at comparable levels. Dependence of changes in one index of the leaf apparatus on the nature of variation of the other adequately describes the equations of a straight line. Correlation and regression analyzes did not reveal a reliable relationship between the length of the leaf blade and its shape, which is recorded in all variants of the experiment. The indifference of the shape of the leaf blade indicates the stability of its manifestations within the species and determines the expediency of applying this index in solving classification and identification problems when forming the range of plantings.