ПРОСТРАНСТВЕННЫЕ ФАКТОРЫ АДВЕНТИЗАЦИИ ПОДЛЕСКА В ЛЕСОПАРКАХ КРУПНОГО ГОРОДА

Abstract

The dependence of the understory alien plants distribution in urban forests of Yekaterinburg on such factors as urbanization, habitat fragmentation and structure of forest stands has been studied. Young growth and adult individuals of understory shrubs and trees were registered for 11 transects; 103 descriptions in round plots of 400 square meters have been analyzed. The first hypothesis was that the species richness and abundance of alien plants increased and the species richness and abundance of native plants decreased with the urbanization growth. It was partly confirmed for the statement that the species richness and abundance of alien plants increase with the growth of urbanization. However, the species richness and abundance of native species do not decrease. The second hypothesis is that the species richness and abundance of alien understory trees and shrubs are higher at the boundaries of the urban forests compared to their inner parts. This hypothesis has not been proved. The edge effect proper, implying changes of the understory state in the direction from boundary into the forest stand has not been observed either in the group of native species or in the group of alien species. The third hypothesis is that the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas adjacent to roads and in the forest stand with long-term boundaries. This hypothesis is partly confirmed. On the one hand, the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas adjacent to roads compared to areas, adjacent to wastelands. On the other hand, the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas with recently emerging forest stand boundaries compared to areas with the long-term forest stand boundaries.