Toxic impact of the de-icing material to street greenery in Riga, Latvia

摘要

There is little information on the ecological composition of snow on roads as well as the toxic effect of de-icing salt on the ecological status of the street trees (Tilia x vulgaris H.) in Latvia. Tilia x vulgaris is one of the most widespread free species of street greenery in the boreo-nemoral zone - in Central, Northern and Eastern Europe. This investigation was done to find Out the accumulation of de-icing salt (main elements - sodium and chlorine) in the snow-soil-plant system of street greenery in the central part of Riga (2004 2005), in order to reveal the toxic effect oil the ecological Status of the street trees (Tilia x vulgaris). Snow, soil and leaf samples were collected from 27 study sites (eight objects) in the central part of Riga with intense traffic and from three control sites (one object) located in a park area. In a majority of cases, the status of street trees Could be characterized as damaged. There was a high heterogeneity in the Na and Cl concentrations even along one street. Significantly, increased levels of Na and Cl in urban snow, soil and leaf samples were found in comparison with the background values. There was close correlation between the Na, Cl concentration in the leaves and the extent of leaf necrosis. Principal new information oil the critical level for observation visual Tilia x vulgaris leaf necrosis was stated based on Our results: 0.14% Na and 0.66% Cl concentrations in the leaves. (c) 2008 Elsevier GmbH. All rights reserved.