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

Aims: 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. Materials & Methods: After selecting a mine area, ۱۶ plots (۲۰×۲۰m) were established by systematic-randomly (۶۰×۶۰m) in an area of ۴ ha (۲۰۰×۲۰۰m-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 ۰-۱۰cm depth in each plot. To study the spatial-pattern of soil properties and lead and cadmium concentrations in the mining area, an area of ۸۰×۸۰m (the mine at the center) was considered and ۸۰ soil samples were systematic-randomly taken (۱۰m intervals). Geostatistical analysis was performed via Kriging method and GS+ software. Findings: 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: ۱۰.۹۷±۰.۳۰, Cd: ۱۸۴.۴۷±۶.۲۶mg.Kg-۱) in comparison to control-area (Pb: ۹.۴۲±۰.۱۷, Cd: ۱۳۱.۷۱±۱۵.۷۷mg.Kg-۱). The range value calculated for variograms of cadmium and lead was ۲۱۰m. The kriged maps showed that the concentration of cadmium and lead near the mine crater was considerably higher in comparison with adjacent points. Conclusion: 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.