Ectomycorrhizal Fungal Community Composition Research Articles

Ectomycorrhizal fungal community structure in a young orchard of grafted and ungrafted hybrid chestnut saplings

Ectomycorrhizal (ECM) fungal community of the European chestnut has been poorly investigated, and mostly by sporocarp sampling. We proposed the study of the ECM fungal community of 2-year-old chestnut hybrids Castanea × coudercii (Castanea sativa × Castanea crenata) using molecular approaches. By using the chestnut hybrid clones 111 and 125, we assessed the impact of grafting on ECM colonization rate, species diversity, and fungal community composition. The clone type did not have an impact on the studied variables; however, grafting significantly influenced ECM colonization rate in clone 111. Species diversity and richness did not vary between the experimental groups. Grafted and ungrafted plants of clone 111 had a different ECM fungal species composition. Sequence data from ITS regions of rDNA revealed the presence of 9 orders, 15 families, 19 genera, and 27 species of ECM fungi, most of them generalist, early-stage species. Thirteen new taxa were described in association with chestnuts. The basidiomycetes Agaricales (13 taxa) and Boletales (11 taxa) represented 36% and 31%, of the total sampled ECM fungal taxa, respectively. Scleroderma citrinum, S. areolatum, and S. polyrhizum (Boletales) were found in 86% of the trees and represented 39% of total ECM root tips. The ascomycete Cenococcum geophilum (Mytilinidiales) was found in 80% of the trees but accounted only for 6% of the colonized root tips. These results could help to unveil the impact of grafting on fungal symbionts, improving management of chestnut agro-ecosystems and production of edible fungal species.

High resilience of the mycorrhizal community to prescribed seasonal burnings in eastern Mediterranean woodlands.

Fire effects on ecosystems range from destruction of aboveground vegetation to direct and indirect effects on belowground microorganisms. Although variation in such effects is expected to be related to fire severity, another potentially important and poorly understood factor is the effect of fire seasonality on soil microorganisms. We carried out a large-scale field experiment examining the effects of spring (early-dry season) versus autumn (late-dry- season) burns on the community composition of soil fungi in a typical Mediterranean woodland. Although the intensity and severity of our prescribed burns were largely consistent between the two burning seasons, we detected differential fire season effects on the composition of the soil fungal community, driven by changes in the saprotrophic fungal guild. The community composition of ectomycorrhizal fungi, assayed both in pine seedling bioassays and from soil sequencing, appeared to be resilient to the variation inflicted by seasonal fires. Since changes in the soil saprotrophic fungal community can directly influence carbon emission and decomposition rates, we suggest that regardless of their intensity and severity, seasonal fires may cause changes in ecosystem functioning.

Site fertility and soil water-table level affect fungal biomass production and community composition in boreal peatland forests.

A substantial amount of below-ground carbon (C) is suggested to be associated with fungi, which may significantly affect the soil C balance in forested ecosystems. Ergosterol from in-growth mesh bags and litterbags was used to estimate fungal biomass production and community composition in drained peatland forests with differing fertility. Extramatrical mycelia (EMM) biomass production was generally higher in the nutrient-poor site, increased with deeper water table level and decreased along the length of the recovery time. EMM biomass production was of the same magnitude as in mineral-soil forests. Saprotrophic fungal biomass production was higher in the nutrient-rich site. Both ectomycorrhizal (ECM) and saprotrophic fungal community composition changed according to site fertility and water table level. ECM fungal community composition with different exploration types may explain the differences in fungal biomass production between peatland forests. Melanin-rich Hyaloscypha may indicate decreased turnover of biomass in nutrient-rich young peatland forest. Genera Lactarius and Laccaria may be important in nutrient rich and Piloderma in the nutrient-poor conditions, respectively. Furthermore, Paxillus involutus and Cortinarius sp. may be important generalists in all sites and responsible for EMM biomass production during the first summer months. Saprotrophs showed a functionally more diverse fungal community in the nutrient-rich site.

Habitat specialisation controls ectomycorrhizal fungi above the treeline in the European Alps

Alpine habitats are one of the most vulnerable ecosystems to environmental change, however, little information is known about the drivers of plant-fungal interactions in these ecosystems and their resilience to climate change. We investigated the influence of the main drivers of ectomycorrhizal (EM) fungal communities along elevation and environmental gradients in the alpine zone of the European Alps and measured their degree of specialisation using network analysis. We sampled ectomycorrhizas of Dryas octopetala, Bistorta vivipara and Salix herbacea, and soil fungal communities at 28 locations across five countries, from the treeline to the nival zone. We found that: (1) EM fungal community composition, but not richness, changes along elevation, (2) there is no strong evidence of host specialisation, however, EM fungal networks in the alpine zone and within these, EM fungi associated with snowbed communities, are more specialised than in other alpine habitats, (3) plant host population structure does not influence EM fungal communities, and (4) most variability in EM fungal communities is explained by fine-scale changes in edaphic properties, like soil pH and total nitrogen. The higher specialisation and narrower ecological niches of these plant-fungal interactions in snowbed habitats make these habitats particularly vulnerable to environmental change in alpine ecosystems.

Partner turnover and changes in ectomycorrhizal fungal communities during the early life stages of European beech (Fagus sylvatica L.).

The first life stages of a tree are subject to strong environmental stresses and competition, limiting their chances of survival. Establishing a mutualistic relationship with mycorrhizal fungi during early life stages may increase growth and survival rates of trees, but how mycorrhizal communities assemble during these stages remains unclear. Here, we studied variation in the ectomycorrhizal (EcM) fungal communities in the soil and roots of Fagus sylvatica seedlings and saplings. Fungal DNA was extracted from the soil and seedling and sapling roots collected in 156 plots across the beech-dominated Sonian forest (Belgium) and community composition was determined through metabarcoding. EcM fungal community composition significantly differed between soil, seedlings and saplings. Russula, Amanita and Inocybe were most abundant in soil, while Lactarius and Scleroderma were more abundant in seedling and sapling roots and Xerocomellus and Laccaria were most abundant in sapling roots. Our results provide evidence of partner turnover in EcM fungal community composition with increasing age in the early life stages of F. sylvatica.

The communities of ectomycorrhizal fungal species associated with Betula pendula Roth and Pinus sylvestris L. growing in heavy-metal contaminated soils

AimsPioneer tree species such as Betula pendula and Pinus sylvestris encroach soils contaminated with heavy metals (HMs). This is facilitated by ectomycorrhizal fungi colonizing tree roots. Thus, we evaluated the ectomycorrhizal fungal (EMF) communities of B. pendula and P. sylvestris growing in HM-contaminated soils compared to non-contaminated soils. We also studied the effect of HMs and soil properties on EMF communities and soil fungal biomass.MethodsRoots of B. pendula and P. sylvestris were collected from three HM-contaminated sites and from two non-contaminated sites located in Poland. EMF species were identified using DNA barcoding. Soil fungal biomass was determined by soil ergosterol.ResultsB. pendula and P. sylvestris growing in HM-contaminated soils had similar EMF communities, where Scleroderma, Rhizopogon and Russula as well as ectomycorrhizae of the long-distance exploration type dominated. Among all of the examined soil factors studied, toxicity index (TITotal) was the most significant factor shaping the composition of EMF communities. Despite significant differences in the structure of the EMF communities of trees growing in HM-contaminated sites compared to control sites, no differences in overall diversity were observed.ConclusionsOnly well-adapted EMF species can survive toxic conditions and form ectomycorrhizal symbiosis with encroaching trees facilitating the forest succession on contaminated soils.

Shifts in ectomycorrhizal fungal community composition during the early establishment of native and exotic pine seedlings

Exotic pine trees are often introduced to novel places worldwide. How exotic pines interact with local microbial communities, such as symbiotic ectomycorrhizal (ECM) fungi, during early establishment compared to interactions by their native counterparts remains to be examined in detail. In this study, native masson pine (Pinus massoniana) and exotic slash pine (Pinus elliottii) seedlings were grown in field-collected soil cores. ECM root tips were collected 3- and 6-months after planting and fungi were identified using high-throughput sequencing. We found that host identity was a key factor determining ECM fungal community assembly after 3-months: native pines associated with Rhizopogon while exotic pines associated primarily with ECM generalists. After 6-months growth, however, ECM fungal communities in native and exotic pines were both dominated by Rhizopogon species. We also found that host selections of several pioneer ECM fungi shared by both native and exotic pines may facilitate an exotic pine's establishment. These findings indicate that more attention should be paid to ECM fungal community shuffling by exotic trees during early establishment and, in turn, the influence of the potential changes in ECM fungal communities on local forest ecosystems.

Changes in soil fungal community composition depend on functional group and forest disturbance type.

Disturbances have altered community dynamics in boreal forests with unknown consequences for belowground ecological processes. Soil fungi are particularly sensitive to such disturbances; however, the individual response of fungal guilds to different disturbance types is poorly understood. Here, we profiled soil fungal communities in lodgepole pine forests following a bark beetle outbreak, wildfire, clear-cut logging, and salvage-logging. Using Illumina MiSeq to sequence ITS1 and SSU rDNA, we characterized communities of ectomycorrhizal, arbuscular mycorrhizal, saprotrophic, and pathogenic fungi in sites representing each disturbance type paired with intact forests. We also quantified soil fungal biomass by measuring ergosterol. Abiotic disturbances changed the community composition of ectomycorrhizal fungi and shifted the dominance from ectomycorrhizal to saprotrophic fungi compared to intact forests. The disruption of the soil organic layer with disturbances correlated with the decline of ectomycorrhizal and the increase of arbuscular mycorrhizal fungi. Wildfire changed the community composition of pathogenic fungi but did not affect their proportion and diversity. Fungal biomass declined with disturbances that disrupted the forest floor. Our results suggest that the disruption of the forest floor with disturbances, and the changes in C and nutrient dynamics it may promote, structure the fungal community with implications for fungal biomass-C.

Ectomycorrhizal Plant-Fungal Co-invasions as Natural Experiments for Connecting Plant and Fungal Traits to Their Ecosystem Consequences

Introductions and invasions by fungi, especially pathogens and mycorrhizal fungi, are widespread and potentially highly consequential for native ecosystems, but may also offer opportunities for linking microbial traits to their ecosystem functions. In particular, treating ectomycorrhizal (EM) invasions, i.e., co-invasions by EM fungi and their EM host plants, as natural experiments may offer a powerful approach for testing how microbial traits influence critical ecosystem functions. Forests dominated by EM symbiosis have unique biogeochemistry whereby the extracellular compoundssecretions of EM plants and fungi may also alteraffect carbon (C) and nutrient cycling; moreover, particular lineages of EM fungi have unique functional traits. EM invasions may therefore alter the biogeochemistry of the native landscapes ecosystems they invade, especially nitrogen (N) and carbon (C) cycling. By identifying “response traits” that favor the success of fungi in introductions and invasions (e.g., spore dispersal and germination) and their correlations with “effect traits” (e.g., nutrient-cycling enzymes) that can alter N and C cycling (and affect other coupled elemental cycles), one may be able to predict the ecosystem functional consequences for ecosystems of fungal invasions using biogeochemistry models that incorporate fungal traits. Here, we review what is already known about how EM fungal community composition, traits, and ecosystem functions vary amongdiffer between native and exotic populations, focusing on the example of EM fungi associated with species of Pinus introduced from the Northern into the Southern Hemisphere. We develop hypotheses on how effects of introduced and invasive EM fungi may depend on interactions between exotic soil N availability in the exotic range and EM fungal traits. We discuss how such hypotheses could be tested by utilizing pine Pinus introductions and invasions as a model system, especially when combined with controlled laboratory experiments. Finally, we illustrate how ecosystem modeling can be used to link fungal traits to their consequences for ecosystem N and C cycling in the context of biological invasions, and we highlight exciting avenues for future directions in understanding EM invasion.

Plant-fungal interactions in hybrid zones: Ectomycorrhizal communities of willows (Salix) in an alpine glacier forefield

Abstract Ectomycorrhizal (EcM) fungi are essential for the establishment of woody perennial plants in the European Alps. From continental to local scales, environmental conditions and plant host characteristics can predict EcM community structure and composition. However, it is unclear whether EcM communities of congeneric host species and their hybrids are differentially structured at local scales. We aimed to i) characterize EcM communities of Salix helvetica, Salix purpurea and their hybrids and ii) elucidate the abiotic and biotic factors affecting EcM communities in hybrid zones. We analysed the EcM communities associated with willows in a glacier valley by combining molecular identification of fungi from individual ectomycorrhizas and from soil. We detected diverse EcM fungi forming non-modular and unnested networks, but we did not find significant differences in the overall EcM fungal community richness or composition among parental species and hybrids. Nevertheless, individual fungi differed regarding host preference. Our results demonstrate that in a sub-alpine hybrid zone with heterogeneous geomorphology, host genotype was not a strong predictor of overall EcM fungal community, but it influenced the occurrence of particular fungi.

Influence of the slope aspect on the ectomycorrhizal fungal community of Quercus variabilis Blume in the middle part of the Taihang Mountains, North China

The slope aspect is one of the most critical topographic factors in mountainous areas. Little is known, however, about the effect of the aspect on the ectomycorrhizal (ECM) fungal community. Additionally, we know very little about the composition of ECM fungal communities associated with Quercus variabilis, which is widely distributed in East Asia. In this study, we compared the richness, community composition, and exploration types of ECM fungi associated with Q. variabilis between predominantly south- and north-facing slopes in the Taihang Mountain, North China for the first time. DNA was extracted from the root tips of Q. variabilis, and Illumina MiSeq sequencing was used to identify ECM fungi. In total, 168 operational taxonomic units belonging to 28 genera were detected, and the ECM community was found to be dominated by Russula, Inocybe, Tomentella, Scleroderma, and Cortinarius. Compared with the north-facing slopes, the ECM communities on the south-facing slopes had higher diversity. The community composition and exploration types were directly affected by the slope aspect. Also, the aspect-induced edaphic variables, such as total phosphorus, total nitrogen, total potassium, pH, and soil water content, were important sources of variation in ECM fungal richness and distributions of exploration types. Different genera tended to be distributed in various slope aspects. Cenococcum, Genea, and Clavulina were significantly enriched in north-facing slopes, while Geopora, Helvelosebacina, Scleroderma, Gyroporus, Astraeus, Boletus, Tricholoma, Hebeloma, Cortinarius and unclassified Thelephoraceae were more abundant in south-facing slopes. Hydrophobic ECM fungi were obviously enriched in the south-facing slope, but there was no statistical difference between hydrophilic among the south- and north-facing slopes. Our study deepened our knowledge of the aspect-driven variation in ECM fungal communities associated with Q. variabilis.

Differences in ectomycorrhizal community assembly between native and exotic pines are reflected in their enzymatic functional capacities

Introducing exotic tree species for afforestation out of their natural range may alter the local ectomycorrhizal (ECM) fungal communities. The potential functional consequences shaped by exotic trees with recruited local ECM fungi rather than native trees remain unclear. This study examined (a) whether the composition and extracellular enzyme function of ECM fungal communities differed between native masson pine (Pinus massoniana) and exotic slash pine (Pinus elliottii) during seedling establishment; and (b) how differences in enzyme functioning were linked to the growth pattern of the host plants. Native (masson) and exotic (slash) pine seedlings were planted into soil cores collected from each study site. At three months growth, root tips were collected from seedlings and assayed for ECM fungal community composition using high-throughput sequencing, and functioning using single root tip assays for enzymes associated with N, P and C acquisition. ECM fungi on masson pines showed higher activities of nitrogen- (N-acetylglucosaminidase, 280–300%), phosphorus- (acid phosphatase, 105–152%), and cellulose (β-glucosidase, 204–235%; cellobiohydrolase, 142–255%) compound degrading enzymes compared to those on slash pines. Those differences was attributed to the host-specific performance of certain ECM fungal taxa, such as Rhizopogon spp. Information theory model selection showed that plant nutrient status in masson pines was correlated with the enzymatic contribution of Rhizopogon spp., whereas slash pines depended on a diverse enzyme palette from multiple ECM fungal taxa. Host identity strongly influenced ECM fungal community composition and extracellular enzymatic functions of specific ECM fungal taxa, which could feedback to host establishment and nutrient cycling processes of restored ecosystem. Therefore, the origin of afforestation tree species should be an important factor when selecting tree species for restoration of degraded lands.

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

Biogeographic patterns in ectomycorrhizal (ECM) fungal communities and their drivers have been elucidated, including effects of host tree species and abiotic (climatic and edaphic) conditions. At these geographic scales, genotypic diversity and composition of single host tree species change with spatial and environmental gradients, reflecting their historical dispersal events. However, whether the host genotypes can be associated with the biogeographic patterns of ECM communities remains unclear. We investigated the biogeographic pattern of ECM fungal community associated with the single host species Castanopsis sieboldii (Fagaceae), whose genotypic diversity and composition across the Japanese archipelago has already been evaluated. ECM communities were investigated in 12 mature Castanopsis-dominated forests covering almost the entire distribution range of C. sieboldii, and we quantified the effect of host genotypes on the biogeographic pattern of ECM fungal communities. Richness and community composition of ECM fungi changed with latitude and longitude; these biogeographic changes of ECM community were significantly correlated with host genotypic variables. Quantitative analyses showed a higher relative explanatory power of climatic and spatial variables than that of host genotypic variables for the biogeographic patterns in the ECM community. Our results suggest historical events of host dispersal can affect the biogeographic patterns of the ECM fungal community, while their explanation power was lower than that for climatic filtering and/or fungal dispersal.

Decelerated carbon cycling by ectomycorrhizal fungi is controlled by substrate quality and community composition.

Interactions between symbiotic ectomycorrhizal (EM) and free-living saprotrophs can result in significant deceleration of leaf litter decomposition. While this phenomenon is widely cited, its generality remains unclear, as both the direction and magnitude of EM fungal effects on leaf litter decomposition have been shown to vary among studies. Here we explicitly examine how contrasting leaf litter types and EM fungal communities may lead to differential effects on carbon (C) and nitrogen (N) cycling. Specifically, we measured the response of soil nutrient cycling, litter decay rates, litter chemistry and fungal community structure to the reduction of EM fungi (via trenching) with a reciprocal litter transplant experiment in adjacent Pinus- or Quercus-dominated sites. We found clear evidence of EM fungal suppression of C and N cycling in the Pinus-dominated site, but no suppression in the Quercus-dominated site. Additionally, in the Pinus-dominated site, only the Pinus litter decay rates were decelerated by EM fungi and were associated with decoupling of litter C and N cycling. Our results support the hypothesis that EM fungi can decelerate C cycling via N competition, but strongly suggest that the 'Gadgil effect' is dependent on both substrate quality and EM fungal community composition. We argue that understanding tree host traits as well as EM fungal functional diversity is critical to a more mechanistic understanding of how EM fungi mediate forest soil biogeochemical cycling.

Community composition of ectomycorrhizal fungi associated with Pinus sylvestris var. mongolica plantations of various ages in the Horqin Sandy Land

Abstract Pinus sylvestris var. mongolica is an important afforestation species in northern China. However, P. sylvestris plantations have severely declined in most areas where they have been introduced. Ectomycorrhizal fungi (EMF) are closely related to host plant growth and have important roles in the forest ecosystem, especially in Pinus forests. Hence, EMF may additionally furnish perception toward decline of P. sylvestris plantations. To date, the community composition of EMF associated with P. sylvestris stay vague. Therefore, to characterize the ectomycorrhizal (EM) fungal community, soil-root samples were analyzed from P. sylvestris plantations with three stand ages in the Horqin Sandy Land. (1) EMF associated with P. sylvestris plantations belonged to 2 phyla, 4 classes, 10 orders, 14 families, and 17 genera in the Horqin Sandy Land. The dominant fungal genus was Wilcoxina. (2) The diversity and community composition of EMF differed with stand age (P

Both forest reserves and managed forests help maintain ectomycorrhizal fungal diversity

The present study focuses on ectomycorrhizal (ECM) fungi, a group of fungi that are extremely vital to the functioning of forest ecosystems. Over a three-year period, we monitored above- and belowground communities of ECM fungi in protected and managed stands located in Poland in Central European mixed forests dominated by Scots pine. Ectomycorrhizal fungi have been evaluated in three pairs of forest reserves and adjacent managed forests using a combination of classical and molecular identification methods. We found that the managed forests harbored, in total, a higher number of fungal taxa than the reserves (105 vs. 93); however, no significant difference in the average number of ECM fungal taxa was found between both management strategies (69.0 ± 6.0 vs. 61.3 ± 11.5). This was true both for sporocarps and ectomycorrhizal communities. In terms of environmental factors, soil nitrate concentration and number of trees were found to be the main drivers shaping the ECM fungal communities. The species composition of ECM fungal communities was to a large extent similar between forest reserves and managed forests, and only a small pool of species was found uniquely on one of the stand types. Species of conservation value (red-listed and rare species in Poland) have been noted on stands influenced by both management strategies. Our results suggest that both forest reserves and managed forests contribute to maintaining ECM fungal diversity, with managed forests contributing a higher total taxa pool, and each management regime contributing a certain number of taxa not found in the other.

Restoration of belowground fungal communities in reclaimed landscapes of the Canadian boreal forest

The trajectory of forests establishing on reclaimed oil sands mines in the Canadian boreal forest is uncertain. Soil microbes, namely mycorrhizal fungi, partly underlie successional trajectories of plant communities, yet their role in restoration is often overlooked. Here, we tested the relative importance of common management tools used in restoration—species planted and soil placement—on the recovery of ectomycorrhizal fungal communities over 4 years. Importantly, we further compared the community assembly of fungi on reclaimed landscapes to that in reference ecosystems disturbed to different degrees. This latter test addresses whether disturbance intensity is more important than common management interventions to restore fungal communities in these ecosystems. Three main findings emerged. (1) The effect of tree species planted and soil placement on ectomycorrhizal fungal communities establishing on reclaimed landscapes was dynamic through time. (2) Disturbances that remove or disrupt the organic layer of soils substantially affect the composition of ectomycorrhizal fungal communities. (3) Shifts in the community composition of ectomycorrhizal fungi were driven to a greater extent by disturbance severity than either tree species planted or soil placement.

Legacy effects of tree mortality mediated by ectomycorrhizal fungal communities.

Successive droughts have resulted in extensive tree mortality in the southwestern United States. Recovery of these areas is dependent on the survival and recruitment of young trees. For trees that rely on ectomycorrhizal fungi (EMF) for survival and growth, changes in soil fungal communities following tree mortality could negatively affect seedling establishment. We used tree-focused and stand-scale measurements to examine the impact of pinyon pine mortality on the performance of surviving juvenile trees and the potential for mutualism limitation of seedling establishment via altered EMF communities. Mature pinyon mortality did not affect the survival of juvenile pinyons, but increased their growth. At both tree and stand scales, high pinyon mortality had no effect on the abundance of EMF inocula, but led to altered EMF community composition including increased abundance of Geopora and reduced abundance of Tuber. Seedling biomass was strongly positively associated with Tuber abundance, suggesting that reductions in this genus with pinyon mortality could have negative consequences for establishing seedlings. These findings suggest that whereas mature pinyon mortality led to competitive release for established juvenile pinyons, changes in EMF community composition with mortality could limit successful seedling establishment and growth in high-mortality sites.

Host plant phylogeny and geographic distance strongly structure Betulaceae-associated ectomycorrhizal fungal communities in Chinese secondary forest ecosystems.

Environmental filtering and dispersal limitation are two of the primary drivers of community assembly in ecosystems, but their effects on ectomycorrhizal (EM) fungal communities associated with wide ranges of Betulaceae taxa at a large scale are poorly documented. In this study, we examined EM fungal communities associated with 23 species from four genera (Alnus, Betula, Carpinus and Corylus) of Betulaceae in Chinese secondary forest ecosystems, using Illumina MiSeq sequencing of the ITS2 region. Effects of host plant phylogeny, soil, climate and geographic distance on EM fungal community were explored. In total, we distinguished 1738 EM fungal operational taxonomic units (OTUs) at a 97% sequence similarity level. The EM fungal communities of Alnus had significantly lower OTU richness than those associated with the other three plant genera. The EM fungal OTU richness was significantly affected by geographic distance, host plant phylogeny, soil and climate. The EM fungal community composition was significantly influenced by host plant phylogeny (12.1% of variation explained in EM fungal community), geographic distance (7.7%), soil (4.6%) and climate (1.1%). This finding highlights that environmental filtering linked to host plant phylogeny and dispersal limitation strongly influence EM fungal communities associated with Betulaceae plants in Chinese secondary forest ecosystems.

Host Phylogenetic Relatedness and Soil Nutrients Shape Ectomycorrhizal Community Composition in Native and Exotic Pine Plantations

Exotic non-native Pinus species have been widely planted or become naturalized in many parts of the world. Pines rely on ectomycorrhizal (ECM) fungi mutualisms to overcome barriers to establishment, yet the degree to which host specificity and edaphic preferences influence ECM community composition remains poorly understood. In this study, we used high-throughput sequencing coupled with soil analyses to investigate the effect of host plant identity, spatial distance and edaphic factors on ECM community composition in young (30-year-old) native (Pinus massoniana Lamb.) and exotic (Pinus elliottii Engelm.) pine plantations in China. The ECM fungal communities comprised 43 species with the majority belonging to the Thelephoraceae and Russulaceae. Most species were found associated with both host trees while certain native ECM taxa (Suillus) showed host specificity to the native P. massoniana. ECM fungi that are known to occur exclusively with Pinus (e.g., Rhizopogon) were uncommon. We found no significant effect of host identity on ECM communities, i.e., phylogenetically related pines shared similar ECM fungal communities. Instead, ECM fungal community composition was strongly influenced by site-specific abiotic factors and dispersal. These findings reinforce the idea that taxonomic relatedness might be a factor promoting ECM colonization in exotic pines but that shifts in ECM communities may also be context-dependent.