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Abstract Microinvertebrate abundance was measured, together with forest soil properties and litter components in eight plots dominated by beech and birch during May to August 2001. The results were analysed using ANOVA, stepwise regression and correlation analysis. Both protozoa and nematodes were analysed according to their functional groups. The protozoa were flagellates, ciliates and naked amoebae, and the nematodes were microbial and plant feeding nematodes. Moisture levels were between 28% and 33% in soil, and 50% to 70% in litter. Population numbers were very variable between sites and dates, and showed variable levels between May and July followed by a significant increase in August.ANOVA showed significant site and date effects, mainly in the litter. Stepwise regression models and correlation analysis revealed a number of interactions among separate groups of protozoa and nematodes, as well as their interrelations with fungi and bacteria. In addition, statistical analysis of soil data revealed a number of microfaunal relationships with soil pH, moisture and organic content, whilst in the field layer a number of significant interactions with specific forest litter fractions were found.The results have revealed particularly high levels of microfaunal abundance in the litter fraction compared to the soil, with flagellates and microbial feeding nematodes showing the highest levels among the trophic groups studied. These data compare well with other studies in similar ecosystems. The invertebrates present appear to be concentrated in hotspots of biological activity. In soil, they may predominantly have been confined to the rhizosphere. In the litter, their numbers may have been enhanced by nutrient availability, which may have increased throughout the study period owing to the gradual progress of decomposition facilitated by the combination of faunal, bacterial and fungal activity.

Abstract The micro and meso-invertebrate abundance was measured, together with forest litter composition, in eight plots of differing vegetation (dominated by beech and birch) over a winter-spring period. The litter moisture content was a mean of 76% during the sampling period and the beech sites were the driest. The results were analysed using a suite of statistical techniques, together with data on protozoa, fungi and bacteria available from parallel research. Nematodes were analysed according to the trophic levels, which included microbial feeders, plant feeders and predators. The majority of arthropods found were the collembolan, Folsomia candida and cryptostigmatid mites, with very small quantities of other micro- and mesoarthropods (such as larvae and mesostigmatid mites). The microarthropod populations peaked in January and fell during subsequent months, while population numbers of nematodes showed a decrease between January and February, followed by an increase in March. ANOVA showed a significant date effect, but no site-date interactions for the population abundance of both nematodes and microarthropods. Ecological interactions of meiofauna were analysed by ANCOVA, stepwise regression, and correlation analysis. Examples of relationships revealed include positive relationships of plant-feeding nematodes (PFN) with microbial feeding nematodes (MFN), and of F. candida with cryptostigmatid mites. Other positive interactions were found for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with litter components, such as beech leaves and litter thickness, moisture and grass, and protozoa. Negative interactions were recorded for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with beech leaves, fungi, protozoa and bacteria. The results have highlighted a very complex structure of factors influencing the temporal and spatial dynamics of the forest litter community. It is suggested that temperature and moisture content particularly influence the invertebrates present. The invertebrates appear to be present in a range of microhabitats, which may have resulted in a reduced level of competition and a high level of positive interactions revealed.

A sufficiently large body of knowledge on British ground beetle (Carabidae) communities now exists to allow investigation of whether habitats may be classified or described on the basis of their ground beetle communities, in the same way that the National Vegetation Classification (NVC) describes British plant communities. A data set of ground beetle abundances from pitfall traps at 481 sites in a range of natural, semi-natural and agricultural habitats throughout Scotland was available for analysis. Multivariate analysis (detrended correspondence analysis and fuzzy cluster analysis) was carried out on proportional catch data of 156 species of ground beetle from 444 of these sites and the results related to the NVC of the sites. Initial analysis classified the sites into five broad categories: 1) peatlands, 2) calcifugous, 3) mesotrophic, 4) dry river sediments and 5) damp river sediments. Further analysis identified 15 ground beetle assemblages, each corresponding to a relatively well defined vegetation type within one of these broad categories. The major environmental factors appearing to determine the distribution of ground beetle assemblages were substratum type, disturbance and soil moisture, all of which are also important determinants of the distribution of plant communities. The presence and absence of relatively stenotopic species were important discriminants of certain habitats such as wetlands and river sediments but the relative abundances within assemblages of more eurytopic species provided good indications of a relationship between ground beetle assemblages and NVC categories.

Interrelations of fungal mycelium with other soil biota are of paramount importance in forestry and soil ecology. Here we present the results of statistical analysis of a comprehensive data set collected in the first (and the only) British fungus sanctuary over a period of four months. The variables studied included a number of soil properties, bacteria, protozoan flagellates, ciliates and amoebae, microbial and plant feeding nematodes, various microarthropods, and two fungal biomarkers--glomalin and ergosterol. One way ANOVA showed that the dynamics of the microbiota studied was influenced by seasonal changes. Superimposed on these changes, however, was variability due to biological interactions and habitat characteristics. Two fungal biomarkers, ergosterol and glomalin, were differently influenced by other biota and abiotic variables. The results indicate that the dynamics of soil fungi is influenced not only by soil microarthropods, but also by those found in forest litter. The overall outcome, therefore, is likely to be very complex and will depend upon specific conditions of any particular ecosystem.