Biogeographic patterns of ectomycorrhizal fungal communities associated withCastanopsis sieboldiiacross the Japanese archipelago

Abstract

23Biogeographic patterns in ectomycorrhizal (ECM) fungal communities and their drivers 24 have been elucidated, including effects of host tree species and abiotic (climatic and 25 edaphic) conditions. At these geographic scales, genotypic diversity and composition of 26 single host tree species change with spatial and environmental gradients, reflecting their 27 historical dispersal events. However, whether the host genotypes can be associated with 28 the biogeographic patterns of ECM communities remains unclear. We investigated the 29 biogeographic pattern of ECM fungal community associated with the single host species 30 Castanopsis sieboldii (Fagaceae), whose genotypic diversity and composition across the 31 Japanese archipelago has already been evaluated, and we quantified the effect of host 32 genotypes on the biogeographic pattern. Richness and community composition of ECM 33 fungi changed with latitude and longitude; these biogeographic changes of ECM 34 community were significantly explained by host genotypic variables. Quantitative 35 analyses showed a higher relative explanatory power of climatic and spatial variables than 36 that of host genotypic variables for the biogeographic patterns in the ECM community. 37 Our results suggest the importance of historical events of host dispersal in determining 38 the biogeographic patterns of the ECM fungal community, while their explanation power 39 was lower than that for climatic filtering and/or fungal dispersal. 40 41 Key words 42 assembly process, biogeography, ectomycorrhiza, environmental gradient, fungal 43 community, host genotype, spatial structure 44 45 48boreal forests (Brundrett, 2009). The ECM fungi are a major component of the forest 49 floor and play an essential role in nutrient cycling via exchanging soil nutrients and 50 therefore are critical for determining and maintaining forest ecosystem processes (Smith 51 & Read, 2008). To infer the community responses to environmental changes, the 52 relationships between spatial patterns of ECM fungal communities and factors 53 responsible for those patterns have been investigated in previous studies (Lilleskov & 54 Parrent, 2007). In these studies the spatial variations of ECM fungal community were 55 related to key environmental factors including both biotic, such as species identity and 56 phylogeny of the host (Ishida et al., 2007; Tedersoo et al., 2013), and abiotic factors, such 57 as soil property (like soil pH) and climatic conditions (e.g., Bahram et al., 2012; Horton 58 et al., 2013). Whereas, recent studies have shown that dispersal of ECM fungi is limited 59 spatially, even at a few kilometers, and that this dispersal limitation can generate spatial 60 structures in ECM fungal communities independent of environmental factors (Peay et al., 61 2012; Peay & Bruns, 2014). Thus far, the effects of these factors have been investigated 62 at relatively small spatial scales, from forest to landscape scales (e.g., Tedersooet et al., 63 2011; Bahram et al., 2012; Matsu...

The ectomycorrhizal fungal communities react differently to climatic, edaphic and spatial variables depending on their host species

“…For ECM fungal communities associated with C . sieboldii , raw sequence data were obtained from Matsuoka et al, (2019), who investigated the ECM fungal communities in 12 C . sieboldii forests (available in the Sequence Read Archive of DNA Data Bank of Japan (DRA) under the accession number: #DRA004281).…”

“…We specifically investigated the ECM fungal community structures in 15 Fagus crenata (Fagaceae) forests across Japan and compared the community structure with that of C . sieboldii forests examined by Matsuoka et al, (2019). We selected the host F .…”

“…The results of Matsuoka et al, (2019) illustrate the necessity of comparing spatial patterns of ECM fungal communities and their driving factors between hosts. Favourable environments and environmental regimes within the distribution range of hosts vary depending on the host species (Fang & Lechowicz, 2006; Kelly & Goulden, 2008).…”

“…Conversely, studies investigating the spatial pattern of ECM fungal community structure and its driving factors within the host's distribution range, that is, focusing on a specific host species, are limited. Matsuoka et al, (2019) investigated the spatial pattern of ECM fungal communities associated with a single host tree species, Castanopsis sieboldii , and revealed that they present a specific spatial structure across the Japanese archipelago. By minimising the effects of other host species, Matsuoka et al, (2019) indicated the possibility that the environmental response and dispersal history of fungi themselves can affect their spatial patterns.…”

Biogeographic Patterns of Ectomycorrhizal Fungal Communities Associated With Castanopsis sieboldii Across the Japanese Archipelago

“…We thank the staff of the University of Tokyo Chiba Forests and Koichi Ito for their assistance in the fieldwork; Shigeaki Hirano and Miyuki Hirata for their assistance in the laboratory work; Yuichiro Kanzaki for the help in the computer work; Ryo Kitagawa for the help in the statistical analyses; and Akira S. Mori, Hirotoshi Sato, and K. Ito for the useful discussions. This manuscript has been released as a preprint at bioRxiv (Matsuoka et al, 2019).…”