Soil Contamination Pattern Affected by Coal Mining Activities in a Deciduous Temperate Forest

The present investigation aimed to study the effect of traditional-coal-mining on the spatial distribution pattern of soil properties in the Lavij-Forest located in the western part of the Hyrcanian area-North Iran.

After selecting a mine area, 16 plots (20×20m) were established by systematic-randomly (60×60m) in an area of 4 ha (200×200m-mine entrance placed at center) which was affected by coal-mining. An area adjacent to the mine (same site conditions) that was not affected by the mining activity considered as the control-area. In order to investigate soil Physio-chemical properties one sample was taken from the 0-10cm depth in each plot. To study the spatial-pattern of soil properties and lead and cadmium concentrations in the mining area, an area of 80×80m (the mine at the center) was considered and 80 soil samples were systematic-randomly taken (10m intervals). Geostatistical analysis was performed via Kriging method and GS+ software.

Results showed that mining had led to a significant decrease in soil moisture, pH, EC, nitrogen, and potassium level. Lead and cadmium concentrations were significantly higher in mine area (Pb: 10.97±0.30, Cd: 184.47±6.26mg.Kg-1) in comparison to control-area (Pb: 9.42±0.17, Cd: 131.71±15.77mg.Kg-1). The range value calculated for variograms of cadmium and lead was 210m. The kriged maps showed that the concentration of cadmium and lead near the mine crater was considerably higher in comparison with adjacent points.

The findings showed that coal mining activity had negative effects on the forest soil and it is necessary to consider reclamation of contaminated soil in these areas.