THE INFLUENCE OF ANTHROPOGENIC EFFECTS ON L. COENOPOPULATION STABILITY IN THE MIDDLE URALS

Abstract

Intensive exploitation of forest resources in the Urals during the last 200 years last resulted in a significant decrease of Juniperus communis L. areal. The aim of the investigation was to estimate the stability of Juniperus communis L. coenopopulations in the Middle Urals on the basis of morphological and physiological parameters of the species. We investigated 3 Juniperus communis coenopopulations in the vicinity of large industrial cities with various recreation and pollution levels in Sverdlovsk region (Baronsk, Staroutkinsk and Nizhny Tagil). Ecological conditions and effective density of specimens were studied in 4 forest types. Besides, life condition categories were estimated on a 5-degree scale. Specimens from Baronsk coenopopulation, growing in the most favourable conditions, belong to the first category, as morphological and physiological indices of the species showed. Injuries made up 10-20 %, while in other populations they accounted for 50 %. In addition to morphological parameters, the coenopopulation stability was estimated by a complex of photosynthetic pigments and potential photosynthetic effectiveness. According to these indices we differentiated coenopopulations with significant distinctions in the levels of recreation impacts.