The role of soil properties variability to reclamation success on the lignite strip-mined land in northern Greece

The present paper present some of the adverse ecological parameters studied for the assessment of reclamation of the lignite spoil heaps of Ptolemaida in North Greece. Natural revegetation was the first step before reclamation began and it was studied. Natural vegetation of lignite spoil heaps was heterogeneous and 7 plant communities were identified, described and mapped. Soil samples geographically positioned indicated that the spoil heaps were heterogeneous and with many unfavourable physicochemical properties. Soil properties were related to natural vegetation and were indicators in assessment of reclamation potentiality of the site. Surface soil temperatures reached 62oC during summer and temperature difference observed between the lightest and darkest spoil materials was 12oC. Between a bare soil and a soil covered by natural vegetation, the soil temperature difference was nearly 20oC. In order to understand the variation of soil properties, graphical interpretation was done with the use of geostatistics in a geographic information system. Cross validation was used to compare the prediction performances of the geostatistical interpolation algorithms. Site quality was estimated from soil properties and natural vegetation composition. The prediction maps resulting from the interpolation techniques help to determine which areas had optimal conditions for forest species development and landscape reclamation success