Soil Fungal Communities Research Articles

Soil fungal communities varied across aspects of restored grassland in former mining areas of the Qinghai-Tibet Plateau.

To determine whether different aspects lead to a heterogeneous distribution of soil fungi, we investigated artificially established alpine grasslands in the Muli mining area in the Qinghai-Tibet Plateau. Employing high-throughput sequencing techniques, we analyzed the composition, diversity, and function of soil fungal communities across various aspects (flat, East-facing, South-facing, West-facing, North-facing). We also examined their relationships with environmental factors. Soil fungal communities of restored alpine grasslands differed significantly across aspects in terms of the dominant phyla, classes and species level. Compared with No aspect, the Shannon index of fungi respectively decreased by 2.99%, 19.32%, 19.37% and 10.56% for East aspect, South aspect, West aspect and North aspect, respectively, and the Chao1 index of fungi respectively decreased by-2.44%, 35.50%, 42.15% and 3.21%, respectively. A total of 22 different types of fungi were identified in the study area. Predictive analysis, based on PICRUSt2, indicated that the primary functions of the fungal communities across different aspects were aerobic respiration I (cytochrome c) and aerobic respiration II (cytochrome c). Among the environmental variables, total phosphorus (P) and total nitrogen (N) were the principal factors influencing the fungal community composition.In conclusion, aspect plays a significant role in shaping the composition of fungal communities and also affects their overall diversity.

Effects of Transformation of Inefficient Camellia oleifera Plantation on Soil Quality and Fungal Communities

Camellia oleifera, a key economic forestry species in southern China, struggles with low productivity due to suboptimal planting management. Recently, transforming old or unadopted varieties of C. oleifera plantations has been recognized as a means to enhance economic benefits and production. However, the impact of these transformations on soil properties and fungal communities has received little attention. In this study, we targeted pre-renewal old C. oleifera and post-renewal young C. oleifera, Pinus massoniana, and Cunninghamia lanceolata. Through field sampling and soil physicochemical property analysis, we developed a soil quality evaluation system that effectively analyzes fungal community structures and identifies key arbuscular mycorrhizal fungi (AMF) species for soil health. We found that the soil quality evaluation system for this region comprises pH, TK, AK, NO3−, PO4− BG, ACP, F.simpson, AMF.shannon, and AMF.ace, which collectively indicated significant improvements in soil quality following transformation. Notably, the nutritional characteristics of the dominant fungal communities underwent marked changes, with an increase in pathogenic fungi in young C. oleifera and an expansion of ectomycorrhizal fungi in P. massoniana forests. The AMF communities in all four types of forest exhibited aggregation, and Scutellospora and Diversispora emerged as key species in the AMF community of C. oleifera. Additionally, Mortierella and Trichoderma were found to enhance plant resistance to pathogenic fungi. This study demonstrates that forestland transformation positively impacts soil quality and fungal community structure in C. oleifera, which provides valuable insights for future soil management in the region, both in terms of soil quality evaluation and fungal conservation.

Effects of slow-release nitrogen and urea combined application on soil physicochemical properties and fungal community under total straw returning condition

Under the system of full straw returning, the relationship between soil fungal community diversity and soil physiochemical properties, and the combined application of slow-release nitrogen and urea is unclear. To evaluate its effect and provide an effective strategy for sustainable agricultural production, a 2-year field positioning trial was conducted using maize as the research object. The experiment was designed with two factors: straw treatment(S) and nitrogen fertilizer treatment(N),Six experimental treatments were set up,S1N0,S1N1,S1N2,S1N3,S1N4,S0N2,respectively.Analysis of 54 soil samples revealed 15 fungal phyla and 49 fungal classes. The composition of fungal communities in each treatment was basically the same, but there were significant differences in species abundance. Under total straw returning conditions, the combined application of slow-release nitrogen fertilizer and normal nitrogen fertilizer significantly increased the relative abundance of Ascomycota. During the jointing stage, tasseling stage and maturity stage, S1N4, S1N3 and S1N2 increased by 25.76%, 22.97%, 20.74%; 25.11%, 30.02%, 23.64% and 22.47%, 28.14%, 22.71% respectively compared with S0N2.The relative abundance of Basidiomycota was significantly reduced. Alpha diversity analysis showed that the straw returning mode significantly increased the Shannon index and decreased the Simpson index, which was obvious in the jointing stage and tasseling stage. The principal coordinate analysis analysis results showed that the fungal communities formed different clusters in the horizontal and vertical directions at the three growth stages of corn jointing, tasseling and maturity. At the jointing stage and tasseling stage, the communities of the straw return treatment and the straw removal treatment were separated, and the community distribution of each treatment was not significantly different in the mature stage. Total straw returning combined with slow-release fertilizer significantly (P＜0.05) increased the soil organic carbon, nitrate nitrogen and ammonia nitrogen content in each growth period, and increased the soil total nitrogen and hydrolyzable nitrogen content (P＞0.05).After the straw was returned to the field, the combined application of slow-release nitrogen fertilizer and common urea had a significant impact on soil urease, catalase, and sucrase activities. Among them, the three enzyme activities were the highest in the S1N3 treatment at the jointing stage and maturity stage, and the S1N4 treatment at the tasseling stage had the highest enzyme activity. Fungal community composition is closely related to environmental factors. Soil organic carbon, urease and catalase are positively correlated with Ascomycota and negatively correlated with Basidiomycota.

Comparison of Microbial Diversity of Two Typical Volcanic Soils in Wudalianchi, China.

Volcanic lava is an excellent model of primary succession, in which basalt-associated microorganisms drive the cycling of different elements such as nitrogen, carbon, and other nutrients. Microbial communities in volcanic soils are of particular interest for study on the emergence and evolution of life within special and extreme conditions. The initial processes of colonization and subsequent rock weathering by microbial communities are still poorly understood. We analyzed the soil bacterial and fungal communities and diversities associated with lava (LBL) and kipuka (BK) sites in Wudalianchi using 16S and ITS rRNA Illumina Miseq sequencing techniques. The results showed that soil physical and chemical properties (pH, MC, TOC, TN, TP, AP, DOC, and DON) significantly differed between LBL and BK. The Shannon, Ace, and Pd indexes of fungi in the two sites showed a significant difference (p < 0.05). The dominant bacterial phyla forming communities at LBL and BK sites were Acidobacteria, Proteobacteria, Actinobacteria, and Basidiomycota, and their differences were driven by Gemmatimonadetes and Verrucomicrobia. The dominant fungal phyla of LBL and BK sites were Ascomycota, Zygomycota, and Rozellomcota, which differed significantly between the two sites. The microbial communities showed extremely significant differences (p < 0.05), with MC, pH, and nitrogen being the main influencing factors according to RDA/CCA and correlation analysis. Microbial functional prediction analysis across the two sites showed that the relative abundance of advantageous functional groups was significantly different (p < 0.05). The combined results drive us to conclude that the volcanic soil differences in the deposits appear to be the main factor shaping the microbial communities in Wudalianchi (WDLC) volcanic ecosystems.

Soil fungal composition under decomposing deadwood is largely affected by tree bark density rather than soil properties

Deadwood is an important structural and biological component of forest ecosystems habitating for a variety of soil fungal communities. However, it is unknown how decomposition of deadwood impacts fungal communities in the soil underneath functionally different tree species in forests. This study compared the effects of the barks of seven tree species, differing in physicochemical characteristics, on soil fungal communities during the early stages of deadwood decomposition in a subtropical forest. A field experiment consisting of 3 evergreen broadleaf, 3 deciduous broadleaf and 1 coniferous tree species, was conducted for 18 months to examine the impact of deadwood decomposition on soil fungal community using real-time PCR and high-throughput sequencing. Our results demonstrated that wood decomposition led to significant declines in soil pH. Functionally distinct tree species significantly shaped the distinct soil fungal composition and abundances underneath the deadwood of both broadleaf and coniferous trees after 18 months of decomposition. The fungal ecological guilds underneath the deadwood were altered, with symbiotrophs being more prominent, and a higher proportion of pathogens were observed under certain broadleaf tree species. Out of the soil fungal ASVs detected, only 51 (3 %) were generalists, while 1053 ASVs (52 %) exhibited traits indicating potential fungal specialists. There were stronger coniferous tree species preferences in soil fungal composition, compared to broadleaf trees. The initial bark density from broadleaf and coniferous species illustrated the most obvious difference. Interestingly, tree bark density, rather than soil chemistry, was the key driver causing the fluctuations in fungal composition during deadwood decomposition. Tree species traits notably affected soil fungal community during early wood decomposition. These findings highlight the importance of considering the bark traits in understanding the dynamics of soil fungal communities and its implications for forest health and ecosystem management.

Differences in soil fungal communities under salinity gradients in arid and semiarid regions

Salinization is considered a significant threat to soil ecosystem and plant growth in arid and semiarid regions. Soil microorganisms are supposed to be essential in relieving soil salinization and enhancing plant salt tolerance. However, although the responses of soil fungal diversity and community structure to salt stress have been investigated, major knowledge gaps remain in the interactions and community assembly of abundant and rare fungal taxa, and fungal functional characteristics under different salt intensities. Here, next-generation sequencing technology were used to investigate the response of all, abundant and rare fungal taxa to salt stress in arid and semiarid regions. The results demonstrated that high salt stress reduced the complexity and stability of fungal networks and increased fungal collaborations. Rare taxa held a key position in the co-occurrence network and exhibited greater proficiency in collaborating with intermediate and rare taxa, thereby augmenting the resistance of the community and maintaining its stability. Notably, with increasing salt stress, the importance of rare taxa gradually enhanced, while the importance of abundant taxa decreased. Moreover, fungal communities were manipulated by stochastic processes under salt stress, while were also influenced by deterministic processes (heterogeneous selection), especially for rare taxa. Furthermore, low salinity conditions promoted the colonization of saprophytic and symbiotic fungi and inhibited the growth of pathogenic fungi. Functional groups associated with fungal parasite-soil saprotroph-undefined saprotroph function were extremely sensitive to soil salinity and exerted a pivotal influence in sustaining community stability. Our findings may broaden our understanding of how abundant and rare fungi react to salt stress, making it easier to forecast the possible loss of biodiversity due to soil salinization, and offering microbial references for the development of saline-alkaline soil.

Facilitating Effects of Reductive Soil Disinfestation on Soil Health and Physiological Properties of Panax ginseng

Chemical soil fumigation (CSF) and reductive soil disinfestation (RSD) have been proven to be effective agricultural strategies to improve soil quality, restructure microbial communities, and promote plant growth in soil degradation remediation. However, it is still unclear how RSD and CSF ensure soil and plant health by altering fungal communities. Field experiments were conducted to investigate the effects of CSF with chloropicrin, and RSD with animal feces on soil properties, fungal communities and functional composition, and plant physiological characteristics were evaluated. Results showed that RSD and CSF treatment improved soil properties, restructured fungal community composition and structure, enhanced fungal interactions and functions, and facilitated plant growth. There was a significant increase in OM, AN, and AP contents in the soil with both CSF and RSD treatments compared to CK. Meanwhile, compared with CK and CSF, RSD treatment significantly increased biocontrol Chaetomium relative abundance while reducing pathogenic Neonectria relative abundance, indicating that RSD has strong inhibition potential. Furthermore, the microbial network of RSD treatment was more complex and interconnected, and the functions of plant pathogens, and animal pathogen were decreased. Importantly, RSD treatment significantly increased plant SOD, CAT, POD activity, SP, Ca, Zn content, and decreased MDA, ABA, Mg, K, and Fe content. In summary, RSD treatment is more effective than CSF treatment, by stimulating the proliferation of probiotic communities to further enhance soil health and plant disease resistance.

Intercropping changed the soil microbial community composition but no significant effect on alpha diversity.

Enhancing the planning of the forest-agricultural composite model and increasing the efficiency with which forest land is utilized could benefit from a thorough understanding of the impacts of intercropping between forests and agriculture on soil physicochemical properties and microbial communities. Populus cathayana × candansis cv. Xinlin No.1 and Glycine max intercrop soils, along with their corresponding monocrops, were used in this study's llumina high-throughput sequencing analysis to determine the composition and diversity of soil bacterial and fungal communities. The findings indicated that intercropping considerably raised the soil's total phosphorus content and significantly lowered the soil's carbon nitrogen ratio when compared to poplar single cropping. Furthermore, the total carbon and nitrogen content of soil was increased and the soil pH was decreased. The sequencing results showed that intercropping had no significant effect on soil alpha diversity. Intercropping could increase the composition of fungal community and decrease the composition of bacterial community in poplar soil. At the phylum level, intercropping significantly increased the relative abundance of four dominant phyla, i.e., Patescibacteria, Proteobacteria, Patescibacteria and Deinococcus-Thermus. And the relative abundances of only two dominant phyla were significantly increased. It was found that soil total phosphorus and available phosphorus content had the strongest correlation with soil bacterial community diversity, and soil pH had the strongest correlation with soil fungal community diversity. The results of this study were similar to those of previous studies. This study can serve as a theoretical foundation for the development of a poplar and black bean-based forest-agricultural complex management system in the future.

Dominant herbaceous plants contribute to the spatial heterogeneity of beech and riparian forest soils by influencing fungal and bacterial diversity

Understanding of factors that shape diversity patterns in forest ecosystems is a main challenge in forest ecology and management practices. Although herbaceous plants are known to contribute to the maintenance of the structure and function of temperate forests, their impact on fungal and bacterial communities in soils is largely unknown. Therefore, we conducted a comparative study of soil fungal and bacterial diversity in two Central European deciduous forests, focusing on plots with dominant herbaceous species of contrasting morphology, phenology, reproduction, and ecology, including Allium ursinum and Dentaria enneaphyllos in a beech forest, as well as Aegopodium podagraria and Ficaria verna in a riparian forest. Plots with a mixture of herbaceous species and without plant cover were also studied. In both forests, fungal communities showed the strongest association with spatial location, part of which was explained by between-site variability in soil chemistry and was also influenced by herbaceous vegetation. The community composition of saprotrophic fungi depended on the presence and type of herbaceous vegetation in both forests. In addition, herbaceous plants affected the composition of arbuscular mycorrhizal fungi community in the beech forest, while in the riparian forest they affected endophytes and plant pathogens. For bacteria, soil chemistry played the most important role. Our results showed that dominant herbaceous vegetation is one of the drivers shaping microbial community composition, contributing to spatial heterogeneity of forest sites. Given that herbaceous species, especially those forming monospecific patches, affect the soil biotic properties in temperate forests, they should be included in forest management practices.

Enhancing boreal forest resilience: A four-year impact of biochar on soil quality and fungal communities

Boreal forests commonly suffer from nutrient deficiency due to restricted biological activity and decomposition. Biochar has been used as a promising strategy to improve soil quality, yet its impacts on forest soil microbes, particularly in cold environment, remains poorly understood. In this study, we investigated the effects of biochar, produced at different pyrolysis temperatures (500 °C and 650 °C) and applied at different amounts (0.5 kg·m−2 and 1.0 kg·m−2), on soil property, soil enzyme activity, and fungal community dynamics in a boreal forest over a span of two to four years. Our results showed that, four-year post-application of biochar produced at 650 °C and applied at 1.0 kg·m−2, significantly increased the relative abundance of Mortierellomycota and enhanced fungal species richness, α-diversity and evenness compared to the control (CK) (P < 0.05). Notably, the abundance of Phialocephala fortinii increased with the application of biochar produced at 500 °C and applied at 0.5 kg·m−2, exhibiting a positively correlation with the carbon cycling-related enzyme β-cellobiosidase. Functionally, distinct fungal gene structures were formed between different biochar pyrolysis temperatures, and between application amounts in four-year post-biochar application (P < 0.05). Additionally, correlation analyses revealed the significance of the duration post-biochar application on the soil properties, soil extracellular enzymes, soil fungal dominant phyla, fungal community and gene structures (P < 0.01). The interaction between biochar pyrolysis temperature and application amount significantly influenced fungal α-diversity (P < 0.01). Overall, these findings provide theoretical insights and practical application for biochar as soil amendment in boreal forest ecosystems.

Drought and vegetation restoration lead to shifts in soil microbial diversity and co-occurrence networks in California coastal prairie

Abstract Background and aims Both drought and vegetation restoration can have dramatic effects on plant community composition, but how they influence soil microbial community diversity, structure, and co-occurrence networks remain less well known. Methods To better understand the regulatory mechanisms of drought and vegetation restoration on soil microorganisms, we planted 12 native species in precipitation manipulation experimental plots in an invaded coastal grassland in California, USA. We measured soil bacterial and fungal community composition by amplicon sequencing, and quantified plant species richness and coverage in the third experimental year. Results Our results showed that drought significantly altered soil bacterial diversity and composition; however, neither drought nor vegetation restoration had significant effects on fungal diversity and composition. The control plots had the most cooperative interactions (greatest number of correlations) among bacterial and/or fungal species, while drought plots yielded the most complex co-occurrence network with the highest modularity and clustering coefficient. Structural equation modeling revealed that plant species richness, net gains, and soil moisture played dominant roles in shaping bacterial community structure. Drought and bacterial community structure directly affected fungal community structure. Plant dominant species cover, common species cover, and bacterial diversity were the key drivers in regulating the microbial co-occurrence network complex. Conclusion We conclude that soil bacterial and fungal communities differ in their responses to abiotic and biotic environmental changes, which may weaken the interspecies interactions among soil microorganisms.

Responses of soil bacterial and fungal community structure and functions to different plant species in a mixed forest plantation in a semi-arid region of China

Soil microbial communities play important roles in biogeochemical cycles and ecosystem functioning. However, how tree and grass species affect soil microbial structure and functions in semi-arid regions is poorly understood. In this study, we used sequencing of representative genes and bioinformatic analysis to compare the soil bacterial and fungal communities and their functional groups among legume and non-legume broad-leaved plantations, conifer plantations, artificial grassland, and adjacent farmland in a semi-arid area of Northern China. We found that soil bacterial diversity and abundance were significantly increased by legume plantations, especially Robinia pseudoacacia, compared to farmland. Soil bacterial communities were dominated by K-strategists in plantation soils and by r-strategists in farmland and grassland soils. Soil fungal communities showed contrasting patterns between Ascomycetes and Basidiomycota across treatments, and the highest abundance of nutrient indicator taxa Mortierellomycota was observed in plantation soils. Functional analysis revealed that afforestation altered the capacity of soil bacteria for organic compound mineralization and C and N cycling, and that different plant species enriched different types of ectomycorrhizal and saprophytic fungi. Moreover, we found that plantations and grasslands formed more connected but less complex and stable bacterial co-occurrence networks than farmland, and that conifer plantations increased the closeness of soil fungal networks compared to broad-leaved plantations. Our results suggest that tree and grass species play a key role in shaping the soil microbial community structure and functional groups, and provide valuable information for choosing suitable tree and grass species for ecosystem restoration and management in semi-arid regions.

Effects of Exogenous Organic Acids on the Soil Metabolites and Microbial Communities of Panax notoginseng from the Forest Understory

Panax notoginseng (Sanqi) is a precious traditional Chinese medicine that is commonly cultivated using conventional management methods in agricultural systems in Yunnan, China, where it faces the challenge of continuous cropping obstacles (CCOs). However, the existence of Sanqi CCOs in Sanqi–pine agroforestry systems remains unclear. Here, we applied three types of exogenous organic acids (phthalic acid, palmitic acid, and phthalic + palmitic mixed organic acids) mainly derived from the root exudates of Sanqi to simulate the CCOs; then, we compared the effects on plant growth, soil physicochemical properties, soil microbes, and soil metabolites. We found that organic acid concentrations of &gt;250 mg/kg reduced the fresh weight of Sanqi and the levels of total nitrogen, ammonium nitrogen, soil water content, total phosphorus, and pH value; these concentrations also increased the soil bacterial and fungal α-diversity. The type of organic acid, as opposed to the concentration and duration of treatment, had a vital impact on the structure of the bacterial and fungal community in Sanqi soils. Moreover, the organic acid concentrations of &gt;250 mg/kg also decreased the complexity and stability of the bacterial and fungal network. In addition, the metabolic pathways in the soils under different organic acids included 17 differential metabolites (DMs), which were involved in steroid hormone biosynthesis. The structural equation models (SEMs) revealed that plant growth, soil edaphic factors, and soil metabolites had direct or indirect influences on soil microbial communities under different organic acid conditions. Our results suggest that any phthalic or palmitic acid concentrations at concentrations &gt;250 mg/kg are detrimental to multiple aspects of Sanqi cultivation, confirming the presence of Sanqi CCOs in Sanqi–pine agroforestry systems.

Microbial Metabolic Limitation and Soil Multifunctionality Changes across Subtropical Woodlands in Southern China

Soil nutrient transformation and the microbial metabolism are primarily regulated by soil microorganisms, including fungi and bacteria, which exhibit distinct growth patterns, energy substrate utilization, and survival strategies. Despite their significance, our understanding of the key microorganisms governing the soil microbial metabolism and multifunctionality in subtropical woodlands remains limited. To address this knowledge gap, we conducted a large-scale investigation and assessment of the soil microbial metabolic limitation and soil multifunctionality in Camellia oleifera Abel and Pinus massoniana Lamb. woodlands in subtropical China. Our results reveal that the microbial phosphorus limitation was more severe in C. oleifera compared to P. massoniana woodlands. Nonetheless, the pattern of carbon metabolic limitation for microbes and soil multifunctionality was similar in both types of woodland. Specifically, the microbial carbon limitation was positively associated with both bacterial and fungal richness, while the microbial phosphorus limitation was significantly correlated with fungi including the richness and community structure in the P. massoniana woodland. By contrast, we did not observe significant correlations between microbial metabolic limitation indices and microbial parameters in C. oleifera woodlands. Regarding soil multifunctionality, the results reveal a strong positive correlation between the soil multifunctionality and fungal community in both P. massoniana and C. oleifera woodlands. Furthermore, our structural equation modeling revealed that the soil fungal community, rather than the bacterial community, had a significant effect on the microbial metabolic limitation and soil multifunctionality. Overall, our study provides profound insights into the relative importance of bacterial and fungal communities in shaping the soil microbial metabolic limitation and soil multifunctionality in subtropical woodlands. The findings of our study have important implications for the management and conservation of subtropical woodlands.

Identification of bacteria and fungi responsible for litter decomposition in desert steppes via combined DNA stable isotope probing.

Soil microorganisms play crucial roles in determining the fate of litter in desert steppes because their activities constitute a major component of the global carbon (C) cycle. Human activities lead to increased ecosystem nitrogen (N) deposition, which has unpredictable impacts on soil microorganism diversity and functions. Nowadays, it is necessary to further study the succession of these microorganisms in the process of litter decomposition in desert steppe, and explore the effect of N deposition on this process. This issue is particularly important to resolve because it contributes to the broader understanding of nutrient cycling processes in desert steppes. In this study, DNA stable isotope probing (DNA-SIP) was used to study changes in soil bacterial and fungal community composition and function during 8 weeks of culture of 13C-labeled litter in desert steppes. The results were as follows: (1) Actinomycetota, Pseudomonadota, and Ascomycota are the main microorganisms involved in litter decomposition in desert steppes; (2) N deposition (50 kg ha-1 year-1) significantly increased the relative abundance of some microorganisms involved in the decomposition process; and (3) N deposition likely promotes litter decomposition in desert steppes by increasing the abundances of N cycles bacteria (usually carrying GH family functional genes). These findings contribute to a deeper understanding of the C assimilation mechanisms associated with litter residue production, emphasizing the importance of extensive C utilization.

Enhanced home-field advantage in deep soil organic carbon decomposition: Insights from soil transplantation in subtropical forests

Climate change affects microbial community physiological strategies and thus regulates global soil organic carbon (SOC) decomposition. However, SOC decomposition by microorganisms, depending on home-field advantage (HFA, indicating a faster decomposition rate in ‘Home’ than ‘Away’ conditions) or environmental advantage (EA, indicating a faster decomposition rate in warmer-wetter environments than in colder-drier environments) remains unknown. Here, a soil transplantation experiment was conducted between warmer-wetter and colder-drier evergreen broadleaved forests in subtropical China. Specifically, soil samples were collected along a 60 cm soil profile, including 0–15, 15–30, 30–45, and 45–60 cm layers after one year of transplantation. SOC fractions, soil chemical properties, and microbial communities were evaluated to assess where there was an HFA of EA in SOC decomposition, along with an exploration of internal linkages. Significant HFAs were observed, particularly in the deep soils (30–60 cm) (P < 0.05), despite the lack of a significant EA along a soil profile, which was attributed to environmental changes affecting soil fungal communities and constraining SOC decomposition in ‘Away’ conditions. The soils transplanted from warmer-wetter to colder-drier environments changed the proportions of Mortiereltomycota or Basidiomycota fungal taxa in deep soils. Furthermore, the shift from colder-drier to warmer-wetter environments decreased fungal α-diversity and the proportion of fungal necromass carbon, ultimately inhibiting SOC decomposition in ‘Away’ conditions. However, neither HFAs nor EAs were significantly present in the topsoil (0–30 cm), possibly due to the broader adaptability of bacterial communities in these layers. These results suggest that the HFA of SOC decomposition in deep soils may mostly depend on the plasticity of fungal communities. Moreover, these results highlight the key roles of microbial communities in the SOC decomposition of subtropical forests, especially in deep soils that are easily ignored.

Contrasting fungal functional groups influence nutrient cycling across four Japanese cool-temperate forest soils

Understanding soil dynamics and nutrient cycling is crucial for the sustainable management of Japanese forests covering 70 % of the national land area. These forests are dominated by tree species with contrasting traits, influencing soil dynamics differently. We investigated how changes in soil characteristics across different forest stands shift in composition and functioning of fungal communities. Four different forest stands dominated by two different mycorrhizal types were selected: Fagus crenata and Larix kaempferi, representing ectomycorrhizal (ECM) types, and Cryptomeria japonica and Robinia pseudoacacia, representing arbuscular mycorrhizal (AM) types. In total, 62 composite topsoil samples from two depths were analyzed for their physicochemical properties and fungal communities were profiled by DNA sequencing. Ectomycorrhizal fungi dominated soils of Fagus crenata and Larix kaempferi forests, while fungal saprotrophs were more abundant in Cryptomeria japonica and Robinia pseudoacacia forests. Forest stand type rather than soil depth determined the composition and structure of soil fungal communities. Soil pH was positively correlated with abundances of saprotrophic fungi (P < 0.05) and negatively with ECM fungi. Soil C:N ratio was positively correlated, and nitrate was negatively correlated with relative abundances of root-associated fungi, primarily ECM fungi. No links between C nor N stocks with fungal guilds were found across the dataset. Observed links between soil C:N ratio and relative abundances of root-associated fungi and saprotrophs stress the importance of these guilds for influencing nutrient cycling economy across contrasting forest types. The lack of correlation between fungal communities and soil C and N stocks suggests distinct mechanisms driving stocks in these soils.

Effects of grazing exclusion on soil properties, fungal community structure, and diversity in different grassland types.

Soil fungi are involved in the decomposition of organic matter, and they alter soil structure and physicochemical properties and drive the material cycle and energy flow in terrestrial ecosystems. Fungal community assembly processes were dissimilar in different soil layers and significantly affected soil microbial community function and plant growth. Grazing exclusion is one of the most common measures used to restore degraded grasslands worldwide. However, changes in soil fungal community characteristics during grazing exclusion in different types of grasslands are unknown. Here, we investigated the effects of a 9-year grazing exclusion on soil properties, fungal community composition, and diversity in three grassland types (temperate desert, temperate steppe, and mountain meadow). The results showed that (1) in the 0-5 cm soil layer, grazing exclusion significantly increased the differences in SWC, SOC, KN, and N:P among the three grassland types, while the final pH, BD, TP, C:N, and C:P values were consistent with the results before exclusion. In the 5-10 cm soil layer, grazing exclusion significantly increased total phosphorus (TP) in temperate deserts by 34.1%, while significantly decreasing bulk density (BD) by 9.8% and the nitrogen: phosphorus ratio (N:P) by 47.1%. (2) The soil fungal community composition differed among the grassland types, For example, significant differences were found among the three grassland types for the Glomeromycota and Mucoromycota. (3) Under the influence of both grazing exclusion and grassland type, there was no significant change in soil fungal alpha diversity, but there were significant differences in fungal beta diversity. (4) Grassland type was the most important factor influencing changes in fungal community diversity, and vegetation cover and soil kjeldahl nitrogen were the main factors influencing fungal diversity. Our research provides a long-term perspective for better understanding and managing different grasslands, as well as a better scientific basis for future research on grass-soil-microbe interactions.

Properties and Fungal Communities of Different Soils for Growth of the Medicinal Asian Water Plantain, Alisma orientale, in Fujian, China.

The Asian water plantain, Alisma orientale (Sam.) Juzep, is a traditional Chinese medicinal plant. The dried tubers of the Alisma orientale, commonly referred to as Alismatis rhizome (AR), have long been used in traditional Chinese medicine to treat a variety of diseases. Soil properties and the soil microbial composition are known to affect the quality and bioactivity of plants. Here, we sought to identify variations in soil fungal communities and soil properties to determine which would be optimal for cultivation of A. orietale. Soil properties, heavy metal content, and pesticide residues were determined from soils derived from four different agricultural regions around Shaowu City, Fujian, China, that had previously been cultivated with various crops, namely, Shui Dao Tu (SDT, rice), Guo Shu Tu (GST, pecan), Cha Shu Tu (CST, tea trees), and Sang Shen Tu (SST, mulberry). As fungi can either positively or negatively impact plant growth, the fungal communities in the different soils were characterized using long-read PacBio sequencing. Finally, we examined the quality of A. orientale grown in the different soils. Our results show that fungal community diversity of the GST soil was the highest with saprotrophs the main functional modes in these and SDT soils. Our data show that GST and SDT soils were most suitable for A. orientale growth, with the quality of the AR tubers harvested from GST soil being the highest. These data provide a systematic approach at soil properties of agricultural lands in need of replacement and/or rotating crops. Based on our findings, GST was identified as the optimal soil for planting A. orientale, providing a new resource for local farmers.

Responses of fungal diversity and community composition after 42 years of prescribed fire frequencies in semi-arid savanna rangelands

Prescribed fire frequencies have been widely used to reduce the risk of severe wildfire occurrences. In addition, several studies have been conducted to assess the impact of fire frequencies on vegetation, vertebrate, and invertebrate species, as well as soil physical and chemical properties. However, there is a lack of empirically based knowledge concerning the impact of fire frequency on soil microorganisms. This study assessed the effect of different fire frequencies on the diversity and composition of soil fungal communities in a semi-arid savanna rangeland. Soil samples were collected from an ongoing long-term trial at the University of Fort Hare (South Africa) on the following treatments: (i) no burning; (ii) annual burning (burned once every year); (iii) biennial burning (burned once every 2 years); (iv) triennial burning (burned once every 3 years); (v) quadrennial burning (burned once every 4 years); and (vi) sexennial burning (burned once every 6 years). Fungi were identified using high-throughput sequencing, with Shannon-Wiener and Inverse Simpson diversity indexes being used for diversity and network analysis. Principal coordinate analysis was used for Bray-Curtis distance matrices to visualise the relationships between treatments. The highest diversity was found in biennial burning, which was significantly different (p &amp;lt; 0.05) from the sexennial, quadrennial, and no burning treatments but was not different from the triennial and annual burning treatments. Regarding the taxa, Ascomycota and Basidiomycota were the phyla with the highest relative abundance, followed by Mortierellomycota, Chytridiomycota, and Rozellomycota. The different fire frequencies had an influence on soil fungi diversity and taxonomic composition in semi-arid savanna rangelands.