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Species and genera of soil nematodes inhabiting tree plantations on colliery spoils near Sokolov
Háněl, Ladislav
Soil nematodes were studied in 20-30-year-old tree plantations and spontaneous successions on colliery spoils near Sokolov in west Bohemia, Czech Republic. Six types of tree plantations (oak, alder, linden, larch, pine, and spruce) and one type of spontaneous succession (willow-aspen-birch), each in four replicate sites, were surveyed in March 2005 and in April 2006. In total 174 species and 86 genera were distinguished, more species and genera were found in deciduous than in coniferous plantations. Cluster analyses showed different composition of nematode faunas in those plantations. Co-occurrence of closely related .i.Aporcelaimellus, Helicotylenchus./i. species could suggest their still existing niche overlap in a developing environment whereas niche partitioning probably established between species of the genera .i.Eudorylaimus./i. and .i.Paratylenchus./i..
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Earthworm assemblages on afforested colliery spoil heaps as affected by tree species
Pižl, Václav
Earthworm assemblages were analysed at twenty-eight colliery spoil heap sites of similar age located in the Sokolov open-cast coal mining district, north-western Bohemia, Czech Republic. Sites afforested with different tree species, namely spruce, pine, larch, oak, lime, and alder, were selected for the study in four replicates each, and compared with un-reclaimed sites covered with spontaneously developed vegetation. No difference was found in the density of earthworms between un-reclaimed sites and coniferous stands, however, a significant effect of tree species on worm density was observed at sites with deciduous afforestation. Dense earthworm populations developed in alder and lime plantations, while worm density was significantly lower under oak. Similarly, earthworm biomass at sites with coniferous afforestation did not differ from that of un-reclaimed heaps and was significantly lower than those at sites with deciduous afforestation.
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Dominantní hlístice (Nematoda) v prvních patnácti letech primární sukcese na výsypkových jílech
Háněl, Ladislav
Soil nematodes were studied at 13 sites in the colliery spoil heap Pastvina formed of tertiary clays and left to spontaneous succession in the Sokolov coal mining district,Czech Republic. The one-year-old site had a very low abundance of nematodes (1,1-2,7 ind.cm.sup.-2./sup.), in the 5-year-old site nematode populations increased considerably (51,3-137,4 ind.cm.sup.-2./sup.) and in older sites they varied (7,9-1023,0 ind.cm.sup.-2./sup.) without detectable relationships with the age of the site. On the other hand, the diversity of nematode assemblages increased with the age of the site and developing plant cover. Bacterivorous and fungivorous nematodes occurred at all sites, having a eudominant position in many assemblages. The distribution of omnivores was variable as some species dominated in the 5-year-old site (.i.Eudorylaimus bombilectus./i.) whereas other (.i.Aporcelaimellus obtusicaudatus./i.) appeared and became eudominant in 14-15-year-old sites.
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Primární sukcese společenstev půdních vířníků na výsypkách po těžbě hnědého uhlí
Devetter, Miloslav
The changes of rotifer soil communities along primary succession chronosequence was studied on brown coal post mining areas near Sokolov, NW part of the Czech Republic. The age of successional stages was 2, 11, 14, 20, 43 years. The rotifers were extracted from soil samples using modified method of Baermann funnel with combined light and temperature gradients. In total, 17 taxa of soil rotifers were identified throughout the study. Most common species were .i.Adineta vaga, Habrotrocha rosa, Macrotrachela quadricornifera./i.. The important were also .i.Encentrum arvicola, Habrotrocha elegans, Macrotrachela nana./i.. Total densities varied from tens to hundreds thousands individuals per m.sup.2./sup. and increased with the increasing age of the plot. Depressions of the surface relief hosted higher numbers of rotifers than elevations, but elevations were more rich in species. The species succession on chronosequence is well demonstrated in the genus .i.Encentrum./i..
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Může průchod střevem žížal ovlivnit strukturu jílových minerálů: předběžné výsledky
Hušák, M. ; Frouz, Jan ; Had, J.
The effect of gut passage by three earthworm species (.i.Lumbricus rubellus, Dendrobaena octaedra, Dendrodrilus rubidus./i.) on the structure of ingested clay minerals was studied using X ray powder diffractometery. No differences were found in the peak's positions in diffraction spectra of clay spoil and clay in earthworm casts, indicating no changes in clay lamella inter-spacing. Differences were found in the peak's sizes, which seem to be caused by changes in preferential orientation of clay minerals during gut passage.
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