Current State of Forest Moss Communities after Reduction of Emissions from the Middle-Ural Copper Smelter

Abstract

The moss cover of forests in an 50×36 km area around the Middle-Ural Copper Smelter was analyzed after almost complete reduction of its emissions. It has been shown that the moss communities in the low and high pollution zones differ significantly in composition, number and frequency of species, but are characterized by a similar cover of ground mosses. The frequency of most species in the high pollution zones, compared to the low pollution zones, was decreased. A significant increase of the frequency in the pollution gradient was found for Pohlia nutans only. Species loss was expressed more strongly on the mesoscale (species richness within a community) than on the macroscale (the total number of species in a pollution zone). The elimination of species under increasing pollution was revealed for species with a low (up to 40%) initial frequency. Despite of the almost complete cessation of emissions from the smelter, the moss cover in the high pollution zones remains severely damaged and is formed by a single species (Pohlia nutans) over a significant area. However, localities with high species richness and high similarity of composition with the background communities occur even under high pollution conditions. The presence of such localities, in combination with a considerable time lag before the extinction of species from the study area as a whole, may have major significance for recolonization of degraded areas after emission reduction.