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Summary The composition of forest litter and understorey layer, and fungal biomass (in terms of ergosterol) were measured in eight subplots over a winter – spring period (January to April). The sampling site was positioned in a range of woodland habitats (variously dominated by beech, Fagus sylvatica ; birch, Betula pendula × pubescens , and oak Quercus petraea ) and a clear area covered with grass (dominated by Holcus lanatus ). The results were analysed together with data on bacteria and microinvertebrates available from parallel research. Levels of ergosterol in individual subplots ranged between 50 and 160 µ g g − 1 DW. Fungal biomass decreased in March, and then increased signifi cantly in April. Stepwise regression models for ergosterol indicated positive relationships with moisture content (February), bacteria (all but February and March), fl agellates (February) and plant-feeding nematodes and fl ies (January, overall). The relationships with roots, seeds, the collective variable ‘ other microinvertebrates ’ (all March), amoebae (February) and fragments (March, overall) were negative, while the relationship between fungi- and microbial-feeding nematodes changed sign between February ( − ) and March (+). Results of analysis of covariance for fungal ergosterol were signifi cant only for January and the combined dataset. In January, fungi were shown to be signifi cantly related to amoebae, bacteria and a collembolan Folsomia candida , while the only signifi cant predictor returned by the overall model was bacteria. Correlation analysis confi rmed some effects already noted, and revealed a number of further interactions. The results highlighted the complexity of factors infl uencing temporal dynamics and spatial variability of

The community dynamics of two- and three-fungal species interactions derived for a tessellated agar model system are described. The microcosm allows for the varied prescription of: (1) the number of fungal species interacting; (2) the spatial configuration (patchiness) of the distribution of individuals; (3) the magnitude of scale of spatial occupation by different fungal individuals; and (4) the operation of antagonistic mechanisms based on contact or longer range diffusible components. Stepwise logistic regressions for two-species interactions are used to inform the design of the multi-species interaction tessellations. The model prescribes and investigates complex parameters, such as spatiotemporal heterogeneity and microcosm scale (e.g. population patchiness and crossing times). Data are quantified as proportion, interface class and state transition class of viable fungal species. Spatiotemporal heterogeneity is represented using a novel application of principal component analysis which shows good intuitive agreement with visual assessment of the interaction outcome patterns, and allows effective comparison of the data as a whole. The model demonstrates the influence of the complex and coordinated behaviour of fungal mycelia on community development: interaction outcome of three-species interactions cannot be directly extrapolated from the relevant binary component interactions; interaction outcomes of the multi-species tessellations appears to be neither random nor fully deterministic; a degree of stochasticity is apparent in all tessellation arrangements; the smaller scale tessellations produce more consistent interaction outcome results, probably because experimental scale affects the duration of transient behaviour; and different initial spatial configurations of inoculum (irrespective of inoculum quantity or proportion) influence community development and reproducibility.