The total content of nitrogen in leaves and wood of trees growing in the area affected by the Głogów Copper Smelter

Abstract

Soils affected by industrial emissions of a copper smelter may contain high amounts of heavy metals. Heavy metal infiltration across the soil is a potential source of groundwater contamination. Simultaneously, many ions, especially Cu2+ and Pb2+, can be accumulated by plants growing within the emission range. The aim of this study was to determine the influence of high Cu and Pb soil contamination on the total nitrogen content in leaves and wood of trees growing in an area exposed to copper smelter emissions. Samples of leaves and wood of Populus robusta L. and Betula pendula L. as well as soil samples were taken from an area affected by industrial emissions, namely from the former sanitary zone of the Glogow Copper Smelter. The samples were collected in 2010. The particle size distribution, pH, organic carbon, total nitrogen and the total content of Cu and Pb in the soil samples were determined. In the plant samples (foliage and trunks), the total nitrogen was assayed. The results were analysed statistically. The following conclusions were drawn: the litter horizon of soils affected by industrial emissions contains high level of heavy metals (3450-5400 mg Cu kg -1 , 1020-1500 mg Pb kg -1 ), exceeding threshold values for industrial areas. Also the humic horizon is characterised by an increased Cu and Pb content: 174-1530 mg Cu kg-1 and 268-702 mg Pb kg-1. The leaves of the tested species contained more nitrogen than the wood, although the birch wood contained more nitrogen then the poplar. There was no difference in the nitrogen content of the annual tree rings of both species. Despite high levels of copper and lead in the tested soils, there was no effect of this factor on the nitrogen content of the leaves, bark and wood of the studied trees.