Actual condition of woody plants and development of sustainable assortment for greening of Saint Petersburg (Russia) in changing climate

Abstract

St. Petersburg is one of the most northern world megapolises. Climate changing, increasing of anthropogenic pressure, diseases and insect pests invasions determine the necessity of trees and shrubs assortment revision. St. Petersburg is known as one of the major centers of introduction works and landscape design development both in Russia and in the world. These work is devoted to estimation of trees and shrubs composition in St. Petersburg greening. The approaches to sustainable assortment development in modern conditions are proposed. Comparative analysis of the alteration of woody plants condition is conducted. The specific adverse factors for woody plants are revealed in St. Petersburg: hard winters (long lasting low temperatures, including in combination with thin snow cover); winter thaw; spring frosts; combination of cool summer and hard winter; air pollution; adverse soil condition (salinization, soil densification, heavy metal pollution), including dryness of soils due to rainfall runoff to the canalization especially in hot summer; plant diseases and pests outbreaks (including as a result of climate warming and plants weakening due to urban environment influence) and new pests and pathogens invasion. Taking into account of these factors is necessary for sustainable assortment development. Reasonable that taxa with different ranges demonstrate the different resistance to the adverse factors.