Assessment of Plantations Ornamentality

Abstract

The issue of biodiversity and sustainability of tree and shrub plantations in large cities is relevant both in Russia and abroad. Their ornamentality is an indicator of adaptation and ability to fully perform their functions. It is relevant to create plantations, decorative throughout the calendar year. The research purpose is to develop a scale for assessing the ornamentality of plantations in urban conditions. This procedure is based on scoring the following characteristics of green spaces: sanitary state; decorative qualities of trunk and crown; characteristics of flowering (according to duration, abundance, color and size of flowers); characteristics of leafing (variety of summer and autumn colors, total duration of leafing). There are 5 most common types of plantations: single-breed arboreal; single-breed shrub; mixed wood; mixed shrub; and woodshrub groups, in which the research was carried out. A mixed group of blue spruce (Picea pungens Eng.), bird cherry (Padus racemosa Lam.) and Hungarian lilac (Syringe josikae Jacg.) has the highest degree of ornamentality in northern conditions (24.8 points). A single-breed plantation of common ninebark (Physocarpus opulifolius L.) has the least ornamentality score (13.1 points), which is due to its sanitary state. The total score depends not only on the species assortment, but also on the plantation sanitary state. The ornamentality score increases with distance from the road, which is due to the improvement in the sanitary state of trees and shrubs (22.8 points at a distance versus 21.4 points near the road). Among all the studied types of plantations in the cities of the Arkhangelsk agglomeration, 50 % have a high degree of ornamentality, 45 % – medium and 5 % – low. Single-breed plantations are generally less decorative than mixed (20.5 points versus 23.4 points). Urban plantations are more or less decorative throughout the entire calendar year. The proposed scheme of the procedure assumes an assessment of decorative effect during all seasons of the year. So, the following should be recorded: the beginning of the period of leafing and flowering in spring; the sanitary state, flowering (duration, abundance, color and size of flowers) in summer; the color scheme of the leaves, the total duration of leafing in autumn; the decorative qualities of trunk and crown (architectonics of crown, coloring of branches) in winter.