1 Scientific RepoRts | 6:31439 | DOI: 10.1038/srep31439 www.nature.com/scientificreports Divergent habitat fltering of root and soil fungal communities in temperate beech forests Kezia Goldmann 1,2,* , Kristina Schröter 3,* , Rodica pena 3 , Ingo Schöning 4 , Marion Schrumpf 4 , François Buscot 1,5 , Andrea Polle 3 & Tesfaye Wubet 1,5 Distance decay, the general reduction in similarity of community composition with increasing geographical distance, is known as predictor of spatial variation and distribution patterns of organisms. However, changes in fungal communities along environmental gradients are little known. Here we show that distance decays of soil-inhabiting and root-associated fungal assemblages difer, and identify explanatory environmental variables. High-throughput sequencing analysis of fungal communities of beech-dominated forests at three study sites across Germany shows that root-associated fungi are recruited from the soil fungal community. However, distance decay is substantially weaker in the root- associated than in the soil community. Variance partitioning of factors contributing to the observed distance decay patterns support the hypothesis that host trees stabilize the composition of root- associated fungi communities, relative to soil communities. Thus, they not only have selective impacts on associated communities, but also bufer efects of changes in microclimatic and environmental variables that directly infuence fungal community composition. A major goal of ecological research is to characterize processes responsible for spatial variation in organism communi- ties 1–2 . Among other aspects there is increasing interest in elucidating drivers of soil fungal communities’ spatial turno- ver 3–5 . Knowledge of specifc environmental factors’ efects on fungal communities is rapidly growing 6–9 . However, little is known about spatial variations in efects of such factors and ecological drivers on fungal communities, and potential modulations of their impacts in difering ecosystem compartments such as roots and the surrounding soil 9–11 . Te similarity of communities declines with increasing distance 12 . Tis “distance decay” 13 could be driven by three main mechanisms. An intuitively obvious mechanism is that environmental conditions become increasingly diferent with increases in geographical distance, resulting in a niche-based community organization as species with diferent functional abilities are selectively recruited and form distinct communities 12,14 . Te other two are modulation of dis- persal rates of taxa by diverse barriers associated with landscape heterogeneity 15 , and dispersal limitations of organisms in homogenous landscapes 1 . Tus, similarity between communities can be afected by both stochastic dispersal and speciation processes, as recognized in the neutral theory 1 , and deterministic (e.g. niche- and dispersal-based) processes that vary among diferent organisms and ecosystems 12,13 . Numerous environmental factors shape soil 16–18 and root-associated 19–21 fungal communities. However, it was recently reported that soil fungal community assemblies are strongly infuenced by stochastic processes 22 . In tem- perate forests, the root-associated fungal communities (RAFC) mainly consist of ectomycorrhizal, saprotrophic, endophytic, or pathogenic fungi 9,23 . Members of these groups are host species dependent and some species are even host-specifc 24–28 . Terefore, besides biotic and abiotic flters, which are common in community assemblies, RAFCs are also infuenced by “host flters” 29 . However, fungi associated with roots are recruited from the surrounding soil fungal community (SFC) 30 , and these recruited components of the SFC depend on local environmental conditions, nutrient availability, plant nutrition and defense strategies, root structure and exudation 31–33 . Tus, the RAFC should pre- sumably be less diverse and less taxa-rich than the surrounding SFC. 1 UFZ-Helmholtz-Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Straße 4, 06120 Halle (Saale), Germany. 2 University of Leipzig, Department of Biology II, Johannisallee 21, 04103 Leipzig, Germany. 3 Georg-August University, Department of Forest Botany and Tree Physiology, Büsgenweg 2, 37077 Göttingen, Germany. 4 Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745 Jena, Germany. 5 German centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany. * these authors contributed equally to this work. correspondence and requests for materials should be addressed to K.G. (email: kezia.goldmann@ufz.de) received: 12 April 2016 accepted: 21 July 2016 Published: 11 August 2016 opeN