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Summary Integrated studies are required to better understand the relationships between groups of soil microfauna under the influence of various biotic and abiotic factors that drive and characterise ecosystems. We analysed soil nematode communities and microbial diversity and the properties of three soil types to assess the effect of these environmental variables on biological diversity in natural (forest), semi-natural (meadow), and managed (agriculture) habitats of the Slovak Republic. The type of ecosystem and soil and the interaction of both factors had considerable effects on most monitored abiotic and biotic soil properties. The forest with a Chernozem soil had the most nematode species, highest nematode diversity, highest abundance of nematode within functional guilds, best values of ecological and functional indices, highest microbial biomass, highest microbial richness and diversity, and the highest values of various soil properties, followed by meadows with a Cambisol soil. The agricultural ecosystem with a Stagnosol soil had the lowest biological diversity and values of the soil properties. Several nematode species were new for Slovak nematode fauna. Sampling date and the interaction of all three factors (ecosystem × soil × date) had minor or no effect on most of the parameters, except soil moisture content, microbial richness, nematode channel ratio, nematode maturity index, and plant parasitic index. Both the biological indicators and basic soil properties indicated that the natural forest with a Chernozem soil was the best habitat from an ecological point of view. This ecosystem is thus the most appropriate for ecological studies.

Summary Nematode communities in a Norway spruce forest in High Tatra National Park, Slovakia were monitored for the period of several years (2006 and 2013). Unfortunately, in May 2014 natural windstorm damaged the forest. This disastrous event, together with preliminary obtained results allowed us to compare the direct impact of windstorm damage of forest habitat on soil nematode assemblages. The forest destruction by windstorm had a significant effect on the total nematode abundance, the abundance of omnivores and herbivores, as well as the nematode species diversity. The most dominant species, representing 55 % of the total nematode fauna, in the plot studied were Acrobeloides nanus followed by Malenchus exiguus, Filenchus vulgaris, Plectus communis, Plectus parvus and Tylencholaimus mirabilis. The abundance of bacterivorous signifi cantly increased after the windstorm, meanwhile the abundance of omnivores, fungivores, and herbivores ectoparasites and epidermal/root hair feeders showed an opposite trend. Of the evaluative indicators, Shannon species diversity (H’spp), maturity index (MI), maturity index 2-5 (MI2-5), sigma maturity index (ΣMI), enrichment index (EI) and structure index (SI) decreased significantly after windstorm. The EI and SI indexes characterized soil ecosystems before windstorm (2006 - 2013) as maturing with low or moderate disturbance, but soil ecosystems shortly after the windstorm (2014) were degraded and nutrient depleted. This also corresponded with graphical display of metabolic footprints characteristics of soil food web. Overall, the nematode communities differed significantly before and after forest damage. These results suggest the role of nematode communities as indicators of environment condition quality or its disruption.

Western corn rootworm, Diabrotica virgifera virgifera, is a pest that needs to be controlled with chemicals in the maize monoculture. The aim of this study was to examine the influence of insecticides on nematode communities in a maize field. Four soil treatments were used in this experiment: variant 1 — a granular application with tefluthrin (199.5 g a.i./ha); variant 2 — a granular application with clothianidin (110 g a.i./ha); variant 3 — a seed treatment with clothianidin (1.25 μg a.i/seed); and control — a maize field without insecticides. During the investigated period, a total of 19 117 soil nematode individuals were captured and 9 orders, 33 genera and 37 species were identified. Acrobeloides nanus, Cephalobus persegnis, Eucephalobus striatus and Basiria gracilis were the dominant species, accounting for 48 % of the total number of individuals. The mean abundance and species diversity index were significantly lower for variant 2. Bacterial feeders were the dominant trophic group for all 4 variants. The numbers of nematodes in particular trophic groups (i.e., bacterial feeders, fungal feeders and omnivores) were significantly different between variant 2 and the control. The Σ Maturity index, Maturity index and Plant parasitic index did not show significant differences among the variants. The higher values of the Enrichment and Structure indices were observed in the first month of the investigation in all 4 variants. A cluster analysis showed that nematode species population densities were strongly affected by the date of soil sample collection and by the variants used in the experiment.

The paper presents research findings on the influence of windfall and wildfire on nematode communities in Lariceto-Piceetum forest in the High Tatras in Slovakia. Comparison was made of an intact (REF), affected and extracted (EXT), non-extracted (NEX) and burnt (FIR) forest stand. A total of 55 species belonging to 36 genera were found. The EXT locality harboured the majority of the identified species, but the highest abundance of nematodes was observed in the FIR locality. Bacterial feeders were the dominant trophic group in all investigated plots. In the REF bacterial feeders were followed by root-fungal feeders, fungal feeders and omnivores, in the EXT by omnivores and plant parasites, in the FIR by omnivores and root-fungal feeders and in the NEX by fungal feeders and omnivores. The MI and SI were higher in the REF and the EXT compared to those in the FIR and the NEX, the highest B/F ratio was observed in the FIR and the highest EI was found in the REF. We can conclude that disturbance of forest vegetation and soil has had a clear and demonstrable impact on nematode communities.

Soil nematodes were studied in 11 meadow sites in the White Carpathians. In total, 155 species and 86 genera were found but the composition of nematode assemblages in eastern and western side of the mountains differed. Most nematode species belonged to the orders Tylenchida (52), Dorylaimida (35) and Rhabditida (16), and to the trophic groups bacterivores (47), plant parasites (29) and omnivores (25). In individual sites and sampling dates the number of species varied in range 18–68, genera 18–52, H’spp 1.32–3.50, H’gen 1.31–3.21, T 1.79–5.70, MI 2.32–3.63, PPI 2.03–2.98, and ΣMI 2.20–3.50. Composition of nematode assemblages and their matrix classification indicated a low degree of anthropogenous disturbance to the meadows.