Stiinta Agricola (Dec 2013)
Экологические особенности внутривидовой конкуренции особей туи западной (Thuja occidentalis l.) в аллеях с простым и сложным ритмами посадки
Abstract
The purpose of our investigation was focused on the processes of spatial and morphological differentiation of white cedar in two row plantations: 1) simple pattern “Fastigiata– Fastigiata” and 2) complex pattern “Fastigiata - Globosa – Fastigiata”. The ecological peculiarities of the columnar white cedar “Fastigiata – Fastigiata” were studied in a 25-year-old street plantation, as well as in an alley plantation. The competition between the individuals of “Fastigiata - Fastigiata” led to their morphological differentiation. In the course of growth, when the crowns begin to touch each other, the trees start to severely compete for light, and because of it slack, some trees are stunted and die. Great deathrates were observed among trees in the street plantation on highly compacted soil that is usually characterizied by a poor aeration and moisture content. In the alley plantation “Fastigiata - Globosa – Fastigiata” (planted in the 60 s), after 50 years the configuration of the row changed because of the morphological differentiation of trees and as a result of their competition for light. The proportion of “cone - globe” elements changed. The extension of the crowns of globular thuja beyond the designed row led to such a negative phenomenon as gravity. In order to enhance the decorativeness of green walls formed of the columnar thuja “Fastigiata”, dead and stunted plants should be systematically removed. Also, to prevent the growing out of globular thuja trees “Globosa”, they must be regularly pruned and brought to the sizes required by plantation design.
