Ectomycorrhizal Research Articles

First report of Caloboletus guanyui (Boletaceae) in India: Taxonomic and phylogenetic insights from Mizoram

The family Boletaceae primarily consists of ectomycorrhizal fungi, which are essential for maintaining the health of forest ecosystems. These fungi form symbiotic relationships with trees, facilitating nutrient exchange and en?hancing plant growth. In the present study, specimens of Caloboletus guan?yui were collected from the Mizoram University campus during the rainy season of 2023. Identification was based on both morphological characteris?tics and molecular analysis of the ITS region of rDNA, with phylogenetic analysis further confirming the distinctiveness of Caloboletus guanyui from closely related species within the genus Caloboletus Vizzini. This medium?sized to large bolete is characterized by its dirty-white to pale-brown pileus and the basidiospores are elliptic-fusiform (spindle-shaped) to subfusiform 9.5–11.5 × 3.5–4.5 ?m. This study represents the first recorded occurrence of Caloboletus guanyui in the tropical moist deciduous forests of Mizoram, India, thereby expanding the known distribution of this species. These new findings enhance our understanding of bolete diversity in India, particularly within the unique forest ecosystems of Mizoram.

Nitrogen deposition changes the root nutrient uptake strategies by affecting microbial diversity of the rhizosphere

Despite the acknowledged importance of rhizosphere fungi in ecosystem functioning, their role in mediating the effects of environmental changes on plant root nutrient uptake strategies remains inadequately understood. To address this gap, long-term nitrogen addition field experiments were conducted to investigate how rhizosphere fungal diversity influences specific root length, a pivotal indicator of plant nutrient uptake rate. The results of the study showed that nitrogen addition significantly augmented specific root length and rhizosphere fungal diversity in both arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species. However, the effects on rhizosphere fungal diversity differed markedly between the two mycorrhizal types. In AM tree species, nitrogen addition decreased rhizosphere beneficial fungal diversity while increasing the diversity of pathogenic fungi. Conversely, ECM tree species exhibited an increase in rhizosphere beneficial fungal diversity and a reduction in pathogenic fungal diversity under nitrogen addition. Furthermore, we identified a positive correlation between the diversity of rhizosphere pathogens and specific root length under nitrogen addition, while a negative correlation was observed under the control. Structural equation modeling further revealed that the indirect effects of nitrogen addition on SRL were mediated through changes in the diversity of rhizosphere beneficial fungi. These findings suggest that nitrogen addition not only directly influences SRL but also exerts significant indirect effects by altering the microbial composition of the rhizosphere. In summary, the study underscores the substantial impact of long-term nitrogen addition on the interactive mechanism of plant physiological characteristics, mediated by pathogenic and beneficial fungi in the rhizosphere of temperate forests.

Effects of ECMF Isolated from Mining Areas on Water Status, Photosynthesis Capacity, and Lead Ion Transport of Populus alba Under Pb Stress

Native ectomycorrhizal fungi (ECMF) are generally more effective than non-native ECMF in facilitating the phytoremediation of heavy metal (HM) ions from contaminated soils. This study aimed to investigate the contributions of four ECMF species—Suillus luteus, Suillus flavidus, Suillus variegatus, and Gomphidius glutinosus—that were isolated from mining areas to the growth, water status, photosynthesis, and metallothionein gene expression of Populus alba exposed to varying concentrations of lead (Pb). The experiment lasted two months and involved P. alba cuttings subjected to Pb concentrations of 0, 200, and 400 mg kg−1, representing no Pb stress, moderate Pb stress, and severe Pb stress, respectively. Results indicated that S. flavidus significantly enhanced the growth, water status, photosynthesis parameters, and metallothionein gene expression of P. alba under Pb stress, whereas S. luteus only exhibited positive effects under severe Pb stress. S. variegatus negatively affected the growth, water status, photosynthesis, and metallothionein gene expression of P. alba under Pb stress, while no significant difference was observed between the control treatment and G. glutinosus symbiosis. Therefore, S. flavidus and S. luteus are promising ECMF species for ecological restoration in mining areas, especially in P. alba woodlands.

Diversity of Ectomycorrhizal Fungal Communities Associated with Tuber koreanum in Korea

Ectomycorrhizal fungi (EMF) are crucial for the formation of Tuber fruiting bodies, including the newly discovered T. koreanum, in Korea. This study explores the diversity and distribution of EMF communities associated with T. koreanum across various regions in Korea and assesses the effects of soil physicochemical properties on these communities. Soil analysis indicated that T. koreanum habitats have a lower pH compared to T. melanosporum habitats documented in other studies, with sandy loam texture being optimal for fruiting body development. Nonmetric multidimensional scaling analysis revealed significant positive correlations between the relative abundances of certain EMF genera and exchangeable potassium and calcium. These findings offer valuable insights into the ecological requirements of T. koreanum and support future conservation and cultivation strategies for truffle species in Korea.

Impact of invasive alien tree species on symbiotic soil fungal communities in pine-dominated forest ecosystems in central Europe

Biological invasions are a serious threat to nature conservation and sustainable forest management. Invasive trees can reduce biodiversity, modify nutrient cycles and transform native forests into novel ecosystems determined by invaders. Almost all European trees form ectomycorrhizal (ECM) symbiosis with fungi, which is crucial for tree development. However, the impact of invasive trees on ECM fungi in native forests has scarcely been studied.We aimed to determine how an invasion of the widespread alien trees Robinia pseudoacacia (which hosts arbuscular mycorrhizal (AM) fungi), Prunus serotina (which forms AM associations and potentially can ECM symbiosis), and Quercus rubra (ECM-dominated, can form AM associations) influences symbiotic fungi in soil. We collected soil samples along a gradient of increasing density of invasive species in 81 stands in pine-dominated forests in Western Poland, identifying fungi through high-throughput sequencing of the ITS2 rDNA, a barcode region for fungi. Each invasive tree was examined independently.Robinia pseudoacacia had the strongest negative impact, almost eliminating ECM fungi from the soil. Among soil compounds, N-NO3 and N-NH4 significantly influenced diversity and taxa composition of ECM fungal communities. Uninvaded pine stands near R. pseudoacacia had significantly lower richness and abundance of ECM fungi, and several-fold higher N-NO3 concentrations, than uninvaded stands elsewhere. That indicates, that the negative impact of Robinia trees extends beyond stands containing Robinia to influence surrounding forests. Prunus serotina had significant negative impact on ECM taxa abundance, but not on ECM taxa richness and diversity indices, while Quercus rubra enhanced the abundance and richness of ECM fungi, but had no significant influence on the diversity indices.

Effects of Ectomycorrhizal Fungi on the Activation and Uptake of Phosphorus in the Mycorrhizal and Hypodermal Layers of Populus davidiana × P. bolleana

Effects of Ectomycorrhizal Fungi on the Activation and Uptake of Phosphorus in the Mycorrhizal and Hypodermal Layers of Populus davidiana × P. bolleana

Impact of stockpiling on soil fungal communities and their functions

Fungal communities are important components of soil biology and play crucial roles in multiple ecosystem functions and services; therefore, they can be used as effective indicators of soil function in stockpiled reclamation soils. We profiled the fungal communities of seven stockpiles of different ages (0.5, 1.5, 2, 5, 7, 11, and 28 years old) at various soil depths (0–300 cm) in two oil sand extraction locations in northern Alberta. Fungal communities of the stockpiles differed from the communities in the nearby undisturbed reference soils. The differences with the reference soils were more pronounced for the oldest and some of the younger stockpiled soils. Similar to previous studies, there was a decrease in fungal richness and overall diversity with increasing stockpile depth. Furthermore, soil stockpiling generated a shift in the functional composition based on inferred fungal guilds and trophic modes. Ectomycorrhizal fungi decreased and saprotrophic fungi increased in the stockpiles relative to the reference soils. Such a shift may have important implications for ecosystem functions and services associated with fungal communities, such as litter decomposition and plant growth promotion, when these stockpiles are used to reclaim ecosystems. Our results align with previous research identifying the negative effects of stockpiling on soil microbial communities, shed light on the soil functions that may be affected by this disturbance and their consequences for ecosystem functioning, and reflect the high sensitivity of fungal communities to soil disturbances like stockpiling.

Effects of different charcoal treatments on the growth of Japanese larch seedlings inoculated with ectomycorrhizal fungi

Effects of different charcoal treatments on the growth of Japanese larch seedlings inoculated with ectomycorrhizal fungi

Light Drought Stress Positively Influenced Root Morphological and Endogenous Hormones in Pinus massoniana Seedlings Inoculated with Suillus luteus

Aims An ectomycorrhizal fungus (ECMF) may enhance plant drought resistance. However, there is limited information regarding the effects of ECMFs on drought resistance in Pinus massoniana Lamb., a native species representing an afforestation pioneer tree in subtropical regions of China. Methods In this study, a pot experiment was conducted to determine the effects of ECMF Suillus luteus inoculation on the root morphology and endogenous hormones of P. massoniana, including roots, leaves, and stems, under various water treatment conditions. Four water levels (regular, light, moderate, and severe drought) and three inoculations (inoculated Suillus luteus, numbered S12 and S13, and non-ECMF-inoculated) were compared using a factorial design. Results Under drought stress, P. massoniana seedlings inoculated with S12 and S13 had significantly increased root morphology development (p < 0.05). Light drought positively influenced root development, resulting in a more than twofold increase in root length and root surface area compared to non-inoculated seedlings. Concentrations of gibberellic acid (GA), zeatin riboside (ZR), and indole-3-acetic acid (IAA) in roots, stems, and leaves of inoculated S12 and S13 plants were elevated, whereas abscisic acid (ABA) concentrations were significantly lower, compared to non-inoculated seedlings. The ABA concentrations in the roots of S12 and S13 inoculated seedlings under light drought stress were 1.5 times lower than those in non-inoculated controls. Moreover, root development was positively correlated with plant total GA, IAA, and ZR but negatively correlated with ABA. ConclusionsS. luteus can promote the root growth and development of P. massoniana seedlings, notably by regulating the balance in the concentration of endogenous hormones, thus improving the drought resistance of P. massoniana seedlings.

Field Reduction of Ectomycorrhizal Fungi Has Cascading Effects on Soil Microbial Communities and Reduces the Abundance of Ectomycorrhizal Symbiotic Bacteria.

Specific interactions between bacteria and ectomycorrhizal fungi (EcMF) can benefit plant health, and saprotrophic soil fungi represent a potentially antagonistic guild to these mutualisms. Yet there is little field-derived experimental evidence showing how the relationship among these three organismal groups manifests across time. To bridge this knowledge gap, we experimentally reduced EcMF in forest soils and monitored both bacterial and fungal soil communities over the course of a year. Our analyses demonstrate that soil trenching shifts the community composition of fungal communities towards a greater abundance of taxa with saprotrophic traits, and this shift is linked to a decrease in both EcMF and a common ectomycorrhizal helper bacterial genus, Burkholderia, in a time-dependent manner. These results not only reveal the temporal nature of a widespread tripartite symbiosis between bacteria, EcMF and a shared host tree, but they also refine our understanding of the commonly referenced 'Gadgil effect' by illustrating the cascading effects of EcMF suppression and implicating soil saprotrophic fungi as potential antagonists on bacterial-EcMF interactions.

Eco-Habitat Assessment of One of the Most Expensive Edible Mushrooms (Tricholoma matsutake) in Genekha, Thimphu, Bhutan

Tricholoma matsutake (S. Ito & Imai) Singer is most expensive edible mushroom, naturally grown dispersed in temperate oak pine forested areas in Bhutan. It is ectomycorrhizal fungi with high ecological and economic value requiring an important ecological niche and symbiotic tree associates. The present study is an attempt to give an account on floristic composition and vegetation structure of Tricholoma matsutake habitat in Genekha, Thimphu. A total of 10 plots were enumerated with plot size of 20m X 20m, 5m X 5m and 2m X 2m for trees, shrubs and herbs respectively. PAST (Paleontological Statistics) 4.10 software was used for diversity analysis. A total of 58 species under 44 genera belonging to 26 families were recorded in the natural habitat of matsutake. The study revealed that T. matsutake is associated with Quercus semecarpifolia Sm., Pinus wallichiana A.B. Jack., Rhododendron spp., and Pieris formosa (Wall.) D. Don. J-shaped distribution curve of DBH and height class with fair regeneration status is obtained for associated species in the habitat. The Menhinick’s species richness of (2.26, 2) for both North facing habitat (NFH) and South facing habitats (SFH) indicated high species richness. Moderate and low diversity is indicated with Simpsons index 0.94 (NFH) and 0.76 (SFH), Shannon index 3.06 (NFH) and 2.49 (SFH) with moderately even distribution 0.74(NFH) and 0.73 (SFH) of species in the habitats. Sorensens similarity index of 0.9 indicated highly similar species composition between two habitats. This research provides current floristic and vegetation structure of Tricholoma matsutake habitat, that will have high significance in habitat management and conservation.

Linking symbioses with intrinsic chemical defences in conifers: Fungal‐mediated resistance against an invasive pathogen

Abstract Invasive pathogens threaten the sustainability of forest ecosystems globally. Trees possess intrinsic pathogen defence mechanisms, including major gene resistance (MGR) and quantitative disease resistance (QDR). Plant‐symbiotic fungi can enhance tree defences, generating far‐reaching ecosystem impacts. However, the specific contributions of various fungal guilds to this symbiont‐mediated resistance remain unclear. In this study, we inoculated six Pinus monticola seedling families exhibiting resistance (MGR or QDR) or high susceptibility to the introduced invasive pathogen Cronartium ribicola, the causative agent of white pine blister rust (WPBR), with endophytic and ectomycorrhizal fungi, either alone or in combination (symbiont treatments), in an open‐air greenhouse study. Over a period of 25 months, we monitored the growth, foliar terpene defences, and disease progression in trees before and after C. ribicola infection and in trees inoculated with the symbionts but never inoculated with C. ribicola. We observed enhanced inducible host defences and evidence of defensive priming in response to symbiont treatments. In WPBR‐free control treatments, differences in pine defences coincided with an increased seedling growth rate. For WPBR‐infected seedlings, symbiont treatments reduced disease symptoms in seedlings with QDR and to a lesser extent in susceptible families, but not in those with MGR. Furthermore, disease symptoms correlated with variations in terpene composition. Synthesis and applications: Interactions with fungal symbionts should be considered when breeding native trees for resistance against invasive pathogens. Our study underscores the capacity of endophytic and ectomycorrhizal fungi to enhance tree growth and defence while also reducing disease symptoms. We also show that fungi can induce long‐lasting changes in conifer foliar terpenes, suggesting potential applications in tree protection from invasive pathogens.

Fire-associated microbial shifts in soils of western conifer forests with Armillaria root disease.

With its influence on ecosystem processes and functions, the soil microbiome can interact with soilborne pathogens to facilitate or suppress plant disease development. These forest ecosystems are experiencing increased wildfire frequency and burn severity that could influence the fungal root pathogen, Armillaria solidipes, and interactions with the soil microbiome. We examined changes to the soil microbiome following three levels of burn severity, and examined how these changes correspond with A. solidipes, and a putatively beneficial species, A. altimontana. Following severe burn, there was a decreased relative abundance of ectomycorrhizal fungi associated A. altimontana. A. solidipes and associated microbial taxa dominated following high-severity burns, suggesting that severe fires provide suitable environmental conditions for these species. Our results suggest that shifts in the soil microbiome and an associated increase in the activity of A. solidipes following high-severity burns in conifer forests may result in priority areas for monitoring and proactive management of Armillaria root disease.

Mycorrhizal and endophytic fungi structure forest below-ground symbiosis through contrasting but interdependent assembly processes

BackgroundInteractions between plants and diverse root-associated fungi are essential drivers of forest ecosystem dynamics. The symbiosis is potentially dependent on multiple ecological factors/processes such as host/symbiont specificity, background soil microbiome, inter-root dispersal of symbionts, and fungus–fungus interactions within roots. Nonetheless, it has remained a major challenge to reveal the mechanisms by which those multiple factors/processes determine the assembly of root-associated fungal communities. Based on the framework of joint species distribution modeling, we examined 1,615 root-tips samples collected in a cool-temperate forest to reveal how root-associated fungal community structure was collectively formed through filtering by host plants, associations with background soil fungi, spatial autocorrelation, and symbiont–symbiont interactions. In addition, to detect fungi that drive the assembly of the entire root-associated fungal community, we inferred networks of direct fungus–fungus associations by a statistical modeling that could account for implicit environmental effects.ResultsThe fine-scale community structure of root-associated fungi were best explained by the statistical model including the four ecological factors/processes. Meanwhile, among partial models, those including background soil fungal community structure and within-root fungus–fungus interactions showed the highest performance. When fine-root distributions were examined, ectomycorrhizal fungi tended to show stronger associations with background soil community structure and spatially autocorrelated patterns than other fungal guilds. In contrast, the distributions of root-endophytic fungi were inferred to depend greatly on fungus–fungus interactions. An additional statistical analysis further suggested that some endophytic fungi, such as Phialocephala and Leptodontidium, were placed at the core positions within the web of direct associations with other root-associated fungi.ConclusionBy applying emerging statistical frameworks to intensive datasets of root-associated fungal communities, we demonstrated background soil fungal community structure and fungus–fungus associations within roots, as well as filtering by host plants and spatial autocorrelation in ecological processes, could collectively drive the assembly of root-associated fungi. We also found that basic assembly rules could differ between mycorrhizal and endophytic fungi, both of which were major components of forest ecosystems. Consequently, knowledge of how multiple ecological factors/processes differentially drive the assembly of multiple fungal guilds is indispensable for comprehensively understanding the mechanisms by which terrestrial ecosystem dynamics are organized by plant–fungal symbiosis.

Tuber cumberlandense and T. canirevelatum, two new edible Tuber species from eastern North America discovered by truffle-hunting dogs

ABSTRACT Ectomycorrhizal fungi in the genus Tuber form hypogeous fruiting bodies called truffles. Many Tuber species are highly prized due to their edible and aromatic ascomata. Historically, there has been attention on cultivating and selling European truffle species, but there is growing interest in cultivating, wild-harvesting, and selling species of truffles endemic to North America. North America has many endemic Tuber species that remain undescribed, including some that have favorable culinary qualities. Here, we describe two such Tuber species from eastern North America. Maximum likelihood and Bayesian phylogenetic analyses of ITS (internal transcribed spacer), tef1 (translation elongation factor 1-alpha), and rpb2 (second largest subunit of RNA polymerase II) sequences were used to place these species within a phylogenetic context. We coupled these data with morphological analyses and volatile analyses based on gas chromatography–mass spectrometry. Tuber cumberlandense, sp. nov. (previously referred to as Tuber sp. 66), is a member of the Rufum clade that has been opportunistically harvested for commercial sale from T. melanosporum orchards across eastern North America. Tuber canirevelatum, sp. nov. belongs in the Macrosporum clade and thus far is only known from eastern Tennessee, USA. Both new species were discovered with the assistance of trained truffle dogs. The volatile profiles of T. canirevelatum and T. cumberlandense were measured in order to characterize aromas based on the chemical compounds produced by these fungi. Ascomata from both species were enriched in acetone, dimethyl sulfide, 1-(methylthio)-1-propene, and 1-(methylthio)propane. In this work, we celebrate and encourage the use of trained truffle-hunting dogs for fungal biodiversity discovery and research.

Variation in functional traits among different mycorrhizal types and life history stages of temperate broadleaf tree species

Exploring the variation in functional traits in plants from different perspectives not only helps reveal the adaptation of plants to their environment but also reflects the ecological strategies of plants. In this study, three species of arbuscular mycorrhizal (AM) trees and three species of ectomycorrhizal (EM) trees were selected in the Heilongjiang Liangshui National Nature Reserve. To investigate the similarities and differences between the functional traits of the two mycorrhizal types of trees at different life history stages, hydraulic traits, anatomical traits, leaf functional traits, and stoichiometry of each species were measured at different life history stages. Traits such as mean vessel area, hydraulic weighted vessel diameter and nitrogen content appeared to be relatively important traits in this study, and all traits were more strongly correlated in AM trees. The sapwood-specific hydraulic conductivity, leaf-specific hydraulic conductivity, vessel density, vessel lumen fraction, nitrogen content and phosphorus content of EM species were significantly higher than those of AM species, while the total vessel area, mean vessel area, hydraulic weighted vessel diameter and density of primary leaf veins of EM species were significantly lower than those of AM species. The leaf mass per area and leaf dry matter content of saplings were significantly lower than those of juvenile trees and adult trees. Most of the trait variation interspecific and intraspecific, and the variability of hydraulic and anatomical traits such as sapwood-specific hydraulic conductivity, leaf-specific hydraulic conductivity, vessel density and total vessel area was relatively large. Leaf dry matter content, hydraulic weighted vessel diameter, vessel density and the vessel lumen fraction contributed significantly to whole branch hydraulic conductivity. It is evident that plastic adjustment and synergistic variation in functional traits are important mechanisms by which plants with different mycorrhizal types and at different life history stages can adapt to different environments.

Long-Term Soil Warming Drives Different Belowground Responses in Arbuscular Mycorrhizal and Ectomycorrhizal Trees.

The ability of trees to acquire soil nutrients under future climate conditions will influence forest composition and function in a warmer world. Rarely are multiple belowground carbon allocation pathways measured simultaneously in large global change experiments, restricting our understanding of how trees may shift their allocation of resources to different nutrient acquisition mechanisms under future climates. Leveraging a 20-year soil warming experiment, we show that ectomycorrhizal (EM) trees reduce mycorrhizal colonization and root exudation while increasing fine root biomass, while arbuscular mycorrhizal (AM) trees largely maintained their belowground carbon allocation patterns in warmer soils. We suggest that AM trees may be better adapted to thrive under global warming due to higher rates of nitrogen mineralization in warmer soils and the ability of their mycorrhizal symbiont to acquire mineralized inorganic nutrients, whereas EM trees may need to alter their belowground carbon allocation patterns to remain competitive as global temperatures rise.

Understanding the ecological versatility of Tetracladium species in temperate forest soils.

Although Tetracladium species have traditionally been studied as aquatic saprotrophs, the growing number of metagenomic and metabarcoding reports detecting them in soil environments raises important questions about their ecological adaptability and versatility. We investigated the factors associated with the relative abundance, diversity and ecological dynamics of Tetracladium in temperate forest soils. Through amplicon sequencing of soil samples collected from 54 stands in six forest sites across the eastern United States, we identified 29 distinct Amplicon Sequence Variants (ASVs) representing Tetracladium, with large differences in relative abundance and small changes in ASV community composition among sites. Tetracladium richness was positively related to soil pH, soil temperature, total sulphur and silt content, and negatively related to plant litter quality, such as the lignin-to-nitrogen ratio and the lignocellulose index. Co-occurrence network analysis indicated negative relationships between Tetracladium and other abundant fungal groups, including ectomycorrhizal and arbuscular mycorrhizal fungi. Collectively, our findings highlight the ecological significance of Tetracladium in temperate forest soils and emphasize the importance of site-specific factors and microbial interactions in shaping their distribution patterns and ecological dynamics.

Peatland Fungal Community Responses to Nutrient Enrichment: A Story Beyond Nitrogen.

Anthropogenically elevated inputs of nitrogen (N), phosphorus (P), and potassium (K) can affect the carbon (C) budget of nutrient-poor peatlands. Fungi are intimately tied to peatland C budgets due to their roles in organic matter decomposition and symbioses with primary producers; however, the influence of fertilization on peatland fungal composition and diversity remains unclear. Here, we examined the effect of fertilization over 10 years on fungal diversity, composition, and functional guilds along an acrotelm (10-20 cm), mesotelm (30-40 cm), and catotelm (60-70 cm) depth gradient at the Mer Bleue bog, Canada. Simultaneous N and PK additions decreased the relative abundance of ericoid mycorrhizal fungi and increased ectomycorrhizal fungi and lignocellulose-degrading fungi. Fertilization effects were not more pronounced in the acrotelm relative to the catotelm, nor was there a shift toward nitrophilic taxa after N addition. The direct effect of fertilization significantly decreased the abundance of Sphagnum-associated fungi, primarily owing to the overarching role of limiting nutrients rather than a decline in Sphagnum cover. Increased nutrient loading may threaten peatland C stocks if lignocellulose-degrading fungi become abundant and accelerate decomposition of recalcitrant organic matter. Additionally, future changes in plant communities, strong water table fluctuations, and peat subsidence after long-term nutrient loading may also influence fungal functional guilds and depth-dependencies of fungal community structure.

Effects of tree species identity on soil microbial communities in Juglans nigra and Quercus rubra plantations.

Understanding how different tree species affect soil microbial communities is crucial for sustainable forestry and ecosystem management practices. Despite Black walnut (Juglans nigra L.) forestry having a rich history, the overall comprehension of how this hardwood species influences soil remains incomplete. In earlier studies, we examined the effects of hardwood plantations on soil chemical properties and their interaction with microbial biomass, however, we highlight the importance of studying the soil microbial communities and their relationship with soil properties in greater depth. Building on this foundation, our research focused on evaluating microbiome compositions beneath J. nigra and another hardwood, Northern red oak (Quercus rubra L.) after a decade of establishment. We uncovered intriguing patterns within the soil bacterial/archaeal and fungal structures by conducting meticulous analyses utilizing amplicon sequencing alongside soil chemical properties. Our findings underscore that tree species play a pivotal role in shaping soil microbial structures, a role that surpasses even seasonal and depth influences. Most notably, J. nigra stands out for its ability to enhance microbial diversity, as evidenced by increased alpha-diversity indices compared to baseline values. Conversely, Q. rubra tends to decrease these indices. Significant disparities in microbial composition between the two tree species were evident, with J. nigra exhibiting enrichment in certain taxa such as Nitrospira, Geobacter, and Bacillus while Q. rubra showed enrichment in others like Acidobacteriota and ectomycorrhizal fungi. Furthermore, we also observed differences in co-occurrence networks by delving deeper into the interconnections within the soil microbiota. In both fungal and bacterial/archaeal communities, J. nigra and Q. rubra notably decreased the number of connections within their networks, while Q. rubra increased some, suggesting a more interconnected network. These differences were further highlighted by network metrics with Q. rubra displaying a higher mean degree and clustering coefficient. Additionally, our analysis revealed that tree species influence soil chemical properties, either directly or indirectly, thereby affecting soil bacterial and fungal communities. In conclusion, our study elucidates the intricate interplay between tree species and soil microbiota, emphasizing the need to consider these relationships in forestry and ecosystem management practices.