ABSTRACT
Spoil banks are created as a consequence of extensive open-cast coal mining in the northern part of the Czech Republic. In the Most coal basin, spoil banks consist mostly of grey Miocene clays, which had to be stored aside in order to access coal. Diverse types of material can occur on newly established spoil banks, varying in the content of consolidated claystones and unconsolidated clays. The ratios of these components are crucial for the characteristics of spoil banks in terms of soil quality and consequent plant growth. Temporarily solid pieces of claystone (consolidated claystone) weather into lamellae. Decomposition of lamellae increases the content of structureless, waterproof clays (unconsolidated clays) with a negative
Institute of Botany, AS CR, Zámek 1, 252 43 Průhonice, Czech Republic. aEmail: jana.rydlova@ibot.cas.cz bEmail: david.puschel@ibot.cas.cz cEmail: martina.janouskova@ibot.cas.cz dEmail: miroslav.vosatka@ibot.cas.cz *Corresponding author
impact on the water regime. While the water conditions are good on freshly deposited material, the situation deteriorates later when unconsolidated material prevails (e.g., spoil banks Růžodol or Albrechtice; Table 1). Spoil banks with a high initial content of unconsolidated clays and a low content of consolidated claystones (e.g., spoil banks Březno or Vršany; Table 1) represent sites with unfavourable physical conditions (extreme liability to erosion, low drainage ability and/or hypoxic conditions) from the very beginning.
