EN
Changes in the below-ground system of ash dumps reclaimed by covering with turf were estimated using parameters and indices based on analysis of nematode communities. Higher trophic diversity, higher values of Maturity Index (MI), and higher complexity of foodweb structure were expected when reclamation proceeded. The study was carried out for three years in chronosequences of ash dumps. Two of the dumps were reclaimed shorter and were studied between the 2nd and 5th year of reclamation, the first one was reclaimed by covering with turf with mineral soil (S-M), the second one with turf with organogenic soil (S-O). The third ash dump reclaimed in longer time, covered with turf with organogenic soil was studied between the 8th–11th year of reclamation (L-O). Until the fourth year of reclamation S-O site provided better conditions for the development of nematodes than S-M site; trophic diversity and MI were higher in S-O site in comparison with S-M site. Later on most parameters and indices were similar in S-M and S-O site. Longer reclamation resulted in higher total abundance, higher abundance of bacterivores, plant feeders and omnivores, and also higher biomass of bacterivores and plant feeders. However, changes in the below-ground system of reclaimed ash dumps were very slow because even after 11 years of reclamation the ash dump had the features of a degraded environment.