The state of the forest ecosystem in an area of oil shale mining and processing: 1. Chemical composition of trees and environment

Abstract

The state of Norway spruce stands on a territory influenced by air pollution from oil shale mining and processing was investigated in 1996-1998. Sample plots were selected in different directions from the industrial centre of Kohtla-Järve (Ida-Viru County, North-East Estonia). After a decrease of the emission of oil shale fly ash and a lower total concentration of pollution from industrial enterprises, the chemical composition of needles and shoots still showed latent injuries and deviations in the biochemical state of trees. Also the soil humus horizon, subsoil water and precipitation were still notably alkaline. © 1999 Estonian Academy Publishers.