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EN
The aim of this study was to compare colonization of pine chips without supplements and pine chips supplemented with forest litter, peat and lignite by mites (Acari), and particularly oribatid mites (Oribatida) in a two-year cycle. The study was conducted in the years 2013-2014, on microplots established in a belt of trees in a nursery in Białe Błota within Bydgoszcz Forest District. The experiment was established on four microplots (1 x 1 m). It included the following variants: C - pine chips alone, Lf – pine chips inoculated with fresh forest litter, Lf+Pe – pine chips enriched with deacidified high peat (20%) (pH 5.5-6.5) and inoculated with the litter, Lf+Li - pine chips enriched with granulated lignite (20%) inoculated with the litter. In the first year of the study, mite abundance in the chips inoculated with forest litter was significantly higher than that on microplot C. In the second year of the experiment, the abundance of these microarthropods decreased probably due to unfavorable weather conditions. The most common group of mites were usually oribatid mites that accounted for 19.7 to 80.4% of all mites. An analysis of seasonal dynamics of Oribatida abundance over the entire study cycle revealed a clear increase in their numbers in non-supplemented pine chips only on the last sampling date. Oribatida abundance in Lf variant was similar at the beginning and end of the study. Contrary to that, their number decreased in the chips supplemented with peat, and particularly those enriched with lignite. In total, 36 species of oribatid mites were identified on all microplots. The greatest boost in species diversity after the introduction of forest litter was observed in Lf chips and the smallest in Lf + Li variant. Oribatula tibialis was the most common oribatid mite in the investigated substrates. Low numbers of Oppiella nova and Tectocepheus velatus, the species having trophic associations with fungi, may indicate poor colonization of the chips, particularly those enriched with lignite, by saprotrophic organisms.
2
Content available remote Importance of different types of beech dead wood for soil microarthropod fauna
EN
Dead wood is an integral part of a forest ecosystem, numerously settled by soil microarthropods (Acari and Collembola), but these animals are rarely studied and often absent from publications dealing with this habitat. Five microarthropod groups in four different types of dead wood (log, stump, snag and tree hollow) and a forest floor were analysed. A core question was to determine the differences in the microarthropod communities, especially oribatid mites, between different types of beech dead wood. The study was carried out in the lowland acidophilus beech forest Luzulo pilosae-Fagetum association. Different types of beech dead wood prove to be a more favourable microhabitat for mites and collembolans than forest soil and litter. Oribatid mites of different dead wood microhabitats represent diverse and partly distinct sub-communities of mites in a forest ecosystem. Oribatid communities of beech dead wood were over 50% distinct. Most oribatid species appeared to be largely restricted to a certain type of beech dead wood.
EN
This paper presents data on temporal and spatial variability and ecological interactions of bacteria in a Scottish woodland over a winter-spring period (January-April). The study sites covered an area of 1 ha and a range of woodland habitats formed by beech (Fagus silvatica), birch (Betula pendula x pubescens) and oak (Quercus petraea), as well as (one site) a clearance site covered with grass (predominantly Holcus lanatus). Subsamples of fresh litter were fragmented for 60 s in a domestic food processor and were subsequently used to estimate the abundance of bacteria by counting under a fluorescent microscope. The preparation of bacterial slides involved staining with DTAF following extraction in phosphate buffer. The data on protozoa, fungi and microinvertebrates were available from parallel research and were obtained using standard methods. Numbers of bacteria appeared to be lower in sites dominated by beech. The highest average bacterial abundance (9.07x108 cells g-1 dry litter) was registered in January, and then gradually declined till March, when the lowest (7.37x108 cells g-1 dry litter) value was found, before rising again in April. The only significant difference revealed by one-way ANOVA was between January and March results. Both date and site effects were found to be significant by two-way ANOVA, but the date site . interaction was not significant. A number of significant relationships were registered by stepwise regression analysis, ANCOVA, and correlation analysis. In stepwise regression analysis, the most important predictor for bacterial density was litter moisture content (all months but March). Further significant relationships were revealed with the abundance of fungi, nematodes, and microarthropods, and forest litter fractions of moss, needles, beech seeds and birch leaves. ANCOVA confirmed the importance of interactions with litter composition and moisture content, and the abundance of fungi and microarthropods, and revealed a relationship with the abundance of ciliates. Correlation analysis for separate months revealed various relationships with forest litter composition (including positive . with forest litter fractions of oak leaves, grass, roots, birch leaves, and negative ones . with forest litter fractions of ferns and seeds), and the abundance of other microbiota, including positive with Folsomia candida (Insecta, Apterygota, Collembola), fungi, plant and microbial feeding nematodes, tardigrades and enchytraeids, positive and negative with ciliates, and negative with predatory nematodes. Most of these relationships, plus a further correlation with the abundance of amoebae, were also revealed for the combined dataset. It should be noted that some of these interactions (e.g. with % grass, % roots, the density of Folsomia candida) were only revealed by correlation analysis, and may therefore be judged as less important than relationships registered by all statistical methods applied. The results of this study highlighted the complexity of multivariate interactions of bacteria in forest litter.
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