Karel Tajovský

Soil biota and upper soil layer development in two contrasting post-mining chronosequences

Abstract Density and community composition of a wide spectrum of soil organisms (fungi, algae, testate amoebae, nematodes, enchytraeids, lumbricids, oribatid mites, diplopods, terrestrial isopods, collembolans and dipteran larvae), direct counts of bacteria, rate of cellulose decomposition and microstructure of upper soil layers were studied in two chronosequences of plots reclaimed from open-cast coal mining near Cottbus (Germany) and near Sokolov (Czech Republic). German plots were characterized by acidic sandy soils and afforested with pine, while the Czech plots possessed alkaline clay soils and were afforested with alder. In both chronosequences, density and species richness in most of investigated groups of soil biota gradually increased with increasing succession age. Typical pioneer species were found in initial stands of both chronosequences. Nevertheless, the initial stands supported poorer assemblages of soil biota in the Cottbus area than did those in the Sokolov area. The Cottbus area was characterized by a moor type of humus and by gradual uniform increase of abundances and species numbers of most studied groups of soil biota. On the contrary, moder type of humus and a more variable pattern of soil biota development during the course of succession were found in the Sokolov area. Slower development of soil biota in initial stages of succession in Cottbus is caused by unfavourable physical and chemical conditions of heap substrates, and by lower input and poor quality of litter in pine plantations.

Soil Food Web Changes during Spontaneous Succession at Post Mining Sites: A Possible Ecosystem Engineering Effect on Food Web Organization?

Parameters characterizing the structure of the decomposer food web, biomass of the soil microflora (bacteria and fungi) and soil micro-, meso- and macrofauna were studied at 14 non-reclaimed 1– 41-year-old post-mining sites near the town of Sokolov (Czech Republic). These observations on the decomposer food webs were compared with knowledge of vegetation and soil microstructure development from previous studies. The amount of carbon entering the food web increased with succession age in a similar way as the total amount of C in food web biomass and the number of functional groups in the food web. Connectance did not show any significant changes with succession age, however. In early stages of the succession, the bacterial channel dominated the food web. Later on, in shrub-dominated stands, the fungal channel took over. Even later, in the forest stage, the bacterial channel prevailed again. The best predictor of fungal bacterial ratio is thickness of fermentation layer. We argue that these changes correspond with changes in topsoil microstructure driven by a combination of plant organic matter input and engineering effects of earthworms. In early stages, soil is alkaline, and a discontinuous litter layer on the soil surface promotes bacterial biomass growth, so the bacterial food web channel can dominate. Litter accumulation on the soil surface supports the development of the fungal channel. In older stages, earthworms arrive, mix litter into the mineral soil and form an organo-mineral topsoil, which is beneficial for bacteria and enhances the bacterial food web channel.

Does autophagy in the midgut epithelium of centipedes depend on the day/night cycle?

The midgut epithelium of two centipedes, Lithobius forficatus and Scolopendra cingulata, is composed of digestive, secretory and regenerative cells. In L. forficatus, the autophagy occurred only in the cytoplasm of the digestive cells as a sporadic process, while in S. cingulata, it occurred intensively in the digestive, secretory and regenerative cells of the midgut epithelium. In both of the species that were analyzed, this process proceeded in a continuous manner and did not depend on the day/night cycle. Ultrastructural analysis showed that the autophagosomes and autolysosomes were located mainly in the apical and perinuclear cytoplasm of the digestive cells in L. forficatus. However, in S. cingulata, the entire cytoplasm was filled with autophagosomes and autolysosomes. Initially the membranes of phagophores surround organelles during autophagosome formation. Autolysosomes result from the fusion of autophagosomes and lysosomes. Residual bodies which are the last stage of autophagy were released into the midgut lumen due to necrosis. Autophagy in the midgut epithelia that were analyzed was confirmed using acid phosphatase and mono-dansyl-cadaverine stainings.

Methane Production and Methanogenic Archaea in the Digestive Tracts of Millipedes (Diplopoda)

Methane production by intestinal methanogenic Archaea and their community structure were compared among phylogenetic lineages of millipedes. Tropical and temperate millipedes of 35 species and 17 families were investigated. Species that emitted methane were mostly in the juliform orders Julida, Spirobolida, and Spirostreptida. The irregular phylogenetic distribution of methane production correlated with the presence of the methanogen-specific mcrA gene. The study brings the first detailed survey of methanogens’ diversity in the digestive tract of millipedes. Sequences related to Methanosarcinales, Methanobacteriales, Methanomicrobiales and some unclassified Archaea were detected using molecular profiling (DGGE). The differences in substrate preferences of the main lineages of methanogenic Archaea found in different millipede orders indicate that the composition of methanogen communities may reflect the differences in available substrates for methanogenesis or the presence of symbiotic protozoa in the digestive tract. We conclude that differences in methane production in the millipede gut reflect differences in the activity and proliferation of intestinal methanogens rather than an absolute inability of some millipede taxa to host methanogens. This inference was supported by the general presence of methanogenic activity in millipede faecal pellets and the presence of the 16S rRNA gene of methanogens in all tested taxa in the two main groups of millipedes, the Helminthophora and the Pentazonia.

DIVERSITY OF TERRESTRIAL ISOPODS (ONISCIDEA) IN FLOODED AND NON FLOODED ECOSYSTEMS OF SOUTHERN MORAVIA, CZECH REPUBLIC

ABSTRACT Characteristic biotopes of the Southern Moravian Region in the Czech Republic were sampled for terrestrial isopods. A total of 18 species were recorded. The highest species diversities were found in the Pavlovske Hills (forests and steppes on limestone), in nonflooded alluvial forests, and in halophilous grasslands. Quantitative studies in six selected flooded and nonflooded ecosystems in the Dyje River alluvium showed the negative impact of spring inundations on terrestrial isopod assemblages. Nonflooded forests were characterized by higher species numbers and much higher densities and biomasses than the flooded ones, where only two species were found with low densities and biomasses. Differences between dry and flooded meadows were small; both biotopes possessed low densities and biomasses of isopods. Trachelipus rathkei, one of the most common species in this region, was the only species able to survive and resettle flooded areas.

Restored meadow harvestman communities (Opiliones) in the Bílé Karpaty Protected Landscape Area, Czech Republic

Harvestman communities inhabiting plots treated differently for grassland restoration were investigated at the Výzkum site near Malá Vrbka village (Bílé Karpaty Protected Landscape Area). Harvestman were sampled by pitfall trapping from 1999 to 2003 on plots sown with native haymeadow seed mixture, also on plots where narrow strips of regional seed mixtures were sown either within a matrix of commercial grass mixture or within vegetation cover in natural regeneration state and on plots in a natural regeneration state. Additionally, harvestman were collected in a field under permanent crop rotation and in a neighbouring xerothermic deciduous forest. In total, 5,086 individuals of harvestman representing 15 species from three families were obtained. Phalangium opilio was dominant (78%) and P. opilio, Rilaena triangularis and Zachaeus crista were the most frequent species. The results confirmed colonisation and subsequent development of harvestman communities on meadows in various state of restoration, including plots with spontaneous plant succession. Nevertheless, biotope character and successive formation of plant cover evidently influenced the structure of harvestman communities. The highest number of taxa (12) was recorded on plots with natural regeneration; the lowest one (9) was recorded in the field with permanent crop rotation. The highest values of diversity and equitability indices of harvestman communities were found in neighbouring forest habitats representing possible sources of harvestman migration.

Millipedes (Diplopoda) in birdsˈ nests

Abstract Nests of birds represent an unusual microhabitat for diverse groups of soil and epigeic invertebrates including millipedes. The millipede faunas of 301 birdsˈ nests from 63 localities throughout Slovakia were obtained by heat extraction of the nest substrates. In total 18 species of millipedes were found in 7 different types of nests of 40 bird species. The most frequent millipede species were Polyxenus lagurus and Proteroiulus fuscus. The similarities in the millipede nidifauna depending on the type of nests, ecological characteristics and geographical distribution of millipede species are discussed.

Hungarosoma bokori Verhoeff, 1928 (Diplopoda: Chordeumatida): new insights into its taxonomy, systematics, molecular genetics, biogeography and ecology

Hungarosoma bokori Verhoeff, 1928 is a millipede species which was originally classified solely on the basis of a female specimen. Subsequently, a long history of field searching for and surmising about the systematic position of this small, enigmatic species followed. In April 2013, 85 years after its first description, a series of nine specimens were sampled in the type locality, the Abaliget Cave, in southern Hungary. An adult male was collected for the first time, along with females and juveniles. Descriptions of the gonopods and the female vulvae, both important for considerations of the systematic position of the species, are presented for the first time. Revision and re-designation of the type material was made.The cryptic life of the species is connected with its activity in winter, and its known fragmented distribution corresponds with its presence in undisturbed microhabitats having a specific microclimate, often in the soil at cave entrances.Molecular methods showed a positive detection of the intracellular prokaryotic parasite Wolbachia in H. bokori, reflecting its highly probable parthenogenetic character in the main part of its known area of occurrence. This is the first demonstration of Wolbachia in a millipede.The legitimacy of the family Hungarosomatidae Ceuca, 1974, as a separate taxon was analysed using morphological and molecular approaches. Results of both methods confirmed the existence of a distinct phyletic line. DNA barcoding has shown its closest position to Attemsiidae Verhoeff, 1899, or Neoatractosomatidae Verhoeff, 1901. Based on records from Austria, the Czech Republic, Hungary and Slovakia, the residual circum-pannonic distribution that the whole genus (family) probably represents is proposed.

Soil Fauna of Peat-Forming Wetlands in a Natural River Floodplain

We assessed the response of soil fauna to natural environmental gradients triggered by different dynamics of hydrological conditions. Four sites differing in the dynamics of groundwater-surface water interactions, type of soil and type of wetland vegetation were selected along a transect running from a river channel to the margin of the valley in the floodplain. Soil macrofauna, represented by millipedes, terrestrial isopods and earthworms, and soil mesofauna (collembolans) were investigated along that transect. Our results demonstrate that soil macrofauna and mesofauna variability differ across examined peat-forming wetlands. The effect of hydrological conditions associated with flooding emerged as a significant predictor of the variability in soil macrofauna with regard to millipedes and terrestrial isopods, but not earthworms. We concluded that the interactive processes reflected in the landscape mosaic, complex spatio-temporal environmental gradients and biogeochemical factors determine the distribution of soil macro and mesofauna within peat-filled river floodplains, although soil fauna components differ in the response across the examined sites.

Influence of surface flattening on biodiversity of terrestrial arthropods during early stages of brown coal spoil heap restoration

Heterogeneity of environmental conditions is the crucial factor supporting biodiversity in various habitats, including post-mining sites. The effects of micro-topographic heterogeneity on biodiversity and conservation potential of arthropod communities in post-industrial habitats had not been studied before now. At one of the largest European brown coal spoil heaps, we sampled eight groups of terrestrial arthropods with different life strategies (moths, spiders, ground beetles, ants, orthopteroids, centipedes, millipedes, and woodlice), in successionally young plots (5-18 y), with a heterogeneous wavy surface after heaping, and compared the communities with plots flattened by dozing. A combination of the standardized quantitative sampling, using two different methods, and a paired design of the plot selection enabled a robust analysis. Altogether, we recorded 380 species of the focal arthropods, 15 of them nationally threatened. We revealed the importance of the micro-topographic heterogeneity for the formation of the biodiversity of arthropods in their secondary refuges. The communities with higher biodiversity and conservation value were detected in the plots with heterogeneous surfaces; exceptions were ground beetles and millipedes. The surface flattening, often the first step of technical reclamation projects, thus suppress biodiversity of most terrestrial arthropods during the restoration of post-mining sites. Since the communities of both surface types differed, the proportional presence on both surfaces could be more efficient in supporting the local biodiversity. We suggest reducing the surface dozing for the cases with other concerns only, to achieve a proportional representation of both surface types. Such a combination of different restoration approaches would, thus, efficiently support high biodiversity of groups with various needs.