Role of Fire Episode, Leaf Litter Decomposition and Mulching Effects in Restoration of the Surface Soil Crust Microecosystem on Abandoned Tailings Containment

This article examines the consequences of a fire (August 1994) which burned the vegetated surface of abandoned tailings containment in mosaic pattern, in Chvaletice (Eastern River Elbe basin, Czech Republic). Vegetation succession with adjacent processes (such as leaf litter decomposition) was then monitored in comparisons on burned and unburned plots. The influence of the introduced plant organic matter by mulching on the biological soil crust was also investigated. Apart from the naturally burned plots, some plots were also experimentally burned. The soil moisture and surface temperatures in different temporal distances from the fire experiment were measured. There were no significant differences in decomposition rate between the plots that were affected and/or unaffected by fire. The daily temperatures of the burned soil surface increased after the fire, while its night temperatures decreased. The moisture content of the soil surface was reduced after the fire. Addition of dry local aboveground plant biomass on the substrate surface suggests that substrate roughness provides retention to seeds transported by wind, and protects the rhizosphere against extreme heat, drought and salt incrustation. Furthermore, it positively modifies the hydrological regime of microsites and stimulates the creation of a humus soil layer and enrichment of the substrate by nutrients. Finally, it facilitates colonisation by plant seedlings from seeds transported by anemochorous or zoochorous mechanisms.