Search Results (240)

Arbuscular mycorrhizal fungi (AMF) taxa, glomalin protein, and hyphal density are potential indicators of soil functionality of temperate grasslands in marginal environments subject to grazing over the years. This study evaluated how the AMF community composition, glomalin protein, and hyphal density vary in response to grazing intensity (low or high) and seasonality (spring and autumn) in sodic soils of Argentinian temperate grasslands. The AMF community was dominated by Glomeraceae species. Funneliformis geosporus and Glomus brohultii were the most abundant in both seasons and all grasslands. No AMF species were associated with a particular grazing intensity. However, Entrophospora etunicata, Glomus fuegianum, Septoglomus constrictum, and Acaulospora sp. occurred only in spring, and no species were exclusive to autumn. Hyphal density was highest in grasslands with low grazing intensity and can be considered an indicator of soil functionality. Glomalin protein was the highest in spring in all grasslands. The lower grazing intensity in grasslands with poor livestock control showed no changes in AMF diversity. The AMF community showed high adaptation to soil conditions, indicating high resilience. We concluded that longer periods of controlled grazing management are needed to improve soil conditions and, consequently, change the AMF species composition. Full article

Soil microbial communities are crucial for ecosystem services, soil fertility, and the resilience of agroecosystems. This study investigated how long-term (31 years) agronomic practices—tillage, NPK fertilization, and cropping system—along with measured environmental variables influence the microbial biomass and its community composition in Chernozem soil under corn cultivation. The polyfactorial field experiment included three tillage treatments ((moldboard (MT), ripped (RT), strip (ST)), two fertilization regimes (NPK (N: 160; P: 26; K: 74 kg/ha), and unfertilized control) and two cropping systems (corn monoculture and corn–wheat biculture). The soil samples (0–30 cm) were collected in June and September 2023. Microbial biomass and community structure were quantified using phospholipid fatty acid (PLFA) analysis, which allowed the estimation of total microbial biomass and community composition (arbuscular mycorrhizal (AM) fungi, fungi, Gram-negative (GN) and Gram-positive (GP) bacteria, actinomycetes). Our results showed that microbial biomass increased from June to September, rising by 270% in unfertilized plots and by 135% in NPK-fertilized plots, due to higher soil moisture. Reduced tillage, especially ST, promoted significantly higher microbial biomass, with biomass reaching 290% and 182% of that in MT plots in June and September, respectively. MT had a higher ratio of bacteria-to-fungi compared to RT and ST, indicating a greater sensitivity of fungi to disturbance. NPK fertilization lowered soil pH by about one unit (to 4.1–4.8) and reduced microbial biomass—by 2% in June and 48% in September—compared to the control, with the particular suppression of AM fungi. The cropping system had a smaller overall effect on microbial biomass. Full article

Arbuscular mycorrhizal fungi (AMF) play a vital role in the restoration of tropical forests by enhancing soil fertility, facilitating plant establishment, and improving ecosystem resilience. This study presents a comprehensive bibliometric analysis of global scientific output on AMF in the context of ecological restoration, based on 3835 publications indexed in the Web of Science and Scopus databases from 2001 to 2024. An average annual growth rate of approximately 9.45% was observed, with contributions from 10,868 authors across 880 journals. The most prominent journals included Mycorrhiza (3.34%), New Phytologist (3.00%), and Applied Soil Ecology (2.79%). Thematically, dominant research areas encompassed soil–plant interactions, phytoremediation, biodiversity, and microbial ecology. Keyword co-occurrence analysis identified “arbuscular mycorrhizal fungi,” “diversity,” “soil,” and “plant growth” as core topics, while emerging topics such as rhizosphere interactions and responses to abiotic stress showed increasing prominence. Despite the expanding body of literature, key knowledge gaps remain, particularly concerning AMF–plant specificity, long-term restoration outcomes, and integration of microbial community dynamics. These findings offer critical insights into the development of AMF research and underscore its strategic importance in tropical forest restoration, providing a foundation for future studies and informing ecosystem management policies. Full article

Soil erosion-prone areas require effective microbial treatments to improve soil bacterial communities and functional traits. Understanding the driving effects of different microbial interventions on soil ecology is essential for restoration efforts. Single and combined microbial treatments were applied to soil. Bacterial community structure was analyzed via 16S IRNA high-throughput sequencing, and functional groups were predicted using FAPROTAX. Soil microbial carbon, nitrogen, metabolic entropy, and enzymatic activity were assessed. Microbial Carbon and Metabolic Activity: The Arbuscular mycorrhizal fungi (AMF) and Bacillus mucilaginosus (BM) (AMF.BM) treatment exhibited the highest microbial carbon content and the lowest metabolic entropy. The microbial carbon-to-nitrogen ratio ranged from 1.27 to 3.69 across all treatments. Bacterial Community Composition: The dominant bacterial phyla included Firmicutes, Proteobacteria, Acidobacteria, Bacteroidetes, and Actinobacteria. Diversity and Richness: The AMF and Trichoderma harzianum (TH) (AMF.TH) treatment significantly reduced diversity, richness, and phylogenetic diversity indices, while the AMF.BM treatment showed a significantly higher richness index (p < 0.05). Relative Abundance of Firmicutes: Compared to the control, the AMF, TH.BM, and TH treatments decreased the relative abundance of Firmicutes, whereas the AMF.TH treatment increased their relative abundance. Environmental Correlations: Redundancy and correlation analyses revealed significant correlations between soil organic matter, magnesium content, and sucrase activity and several major bacterial genera. Functional Prediction: The AMF.BM treatment enhanced the relative abundance and evenness of bacterial ecological functions, primarily driving nitrification, aerobic ammonia oxidation, and ureolysis. Microbial treatments differentially influence soil bacterial communities and functions. The AMF.BM combination shows the greatest potential for ecological restoration in erosion-prone soils. Full article

The biomass allocation patterns between aboveground and belowground are an essential functional trait for plant survival under a changing environment. The effects of arbuscular mycorrhizal fungi (AMF) communities on plant biomass allocation, particularly in degraded Festuca ovina grasslands in ecologically fragile karst areas, remain unclear. Therefore, we conducted a field investigation combined with a greenhouse experiment to explore the importance of AMF compared to bacteria and fungi for plant biomass allocation. The results showed that plant biomass in degraded grasslands exhibited allometric biomass allocation, contrasting with isometric partitioning in non-degraded grasslands. AMF, not bacteria or fungi, were the primary microbial mediators of grassland degradation effects on plant biomass allocation based on structural equation modeling. The greenhouse experiment demonstrated that the selected AMF keystone species from the field study performed according to ecological network analysis, particularly multi-species combinations, enhanced the belowground biomass allocation of F. ovina under rocky desertification stress compared to single-species inoculations, through decreasing soil pH, enhancing alkaline phosphatase (ALP) activity, and increasing the expression level of AMF-inducible phosphate transporter (PT4). This study highlights the critical role of the AMF community, rather than individual species, in mediating plant survival strategies under rocky desertification stress. Full article

Arbuscular mycorrhizal fungi (AMF) exhibit diverse strategies for colonization and survival, yet the extent to which different propagule types—roots, extraradical hyphae, and spores—contribute to these processes remains unclear. In a pot experiment using Allium tuberosum and soils from three field sites, we characterized AMF communities in root, hyphal, and spore fractions through 18S rRNA gene sequencing. A total of 427 OTUs were identified, with Glomus and Paraglomus dominating. Root fractions contained significantly more OTUs than hyphal fractions, suggesting strong specialization for intraradical colonization. Only a small subset of taxa occurred across all propagule types. Indicator species analysis revealed 21 OTUs with significant associations, mainly in root and hyphal fractions, while spore-specific taxa were rare. PERMANOVA revealed that both propagule type and soil type shaped the community structure, with propagule identity being the stronger factor. These results highlight propagule-type specialization as a key ecological trait in AMF and underscore the importance of examining multiple fungal compartments to fully capture AMF diversity and function. Full article

Urban green spaces are integral components of city ecosystems, supporting essential belowground microbial communities such as arbuscular mycorrhizal fungi (AMF). Understanding how green space types influence AMF communities is key to promoting urban ecological function. This study examines AMF diversity, community assembly, and co-occurrence network structures in two urban green space types—park and roadside—in Kaifeng, Henan Province, China. Soil samples were collected from both sites, and AMF community composition was assessed using high-throughput sequencing. Environmental variables, including total nitrogen (TN), available phosphorus (AP), available potassium (AK), water content, and pH, were measured to evaluate their influence on AMF communities. The results indicate marked differences between the two green space types. Park soils support significantly greater AMF species richness and more complex co-occurrence networks than roadside soils. These differences are correlated with higher nutrient levels in park soils. By contrast, AMF communities in roadside soils are more strongly associated with soil water content and pH, resulting in reduced diversity and more homogeneous community structures. Stochastic processes predominantly govern community assembly in both green space types, with roadside green spaces being more influenced by stochastic processes than park green spaces. These findings highlight the influence of urban landscape type on AMF communities and provide guidance for enhancing urban biodiversity through targeted landscape planning and soil management. In future work, we will implement long-term AMF monitoring across different green-space types and evaluate specific management practices to optimize soil health and ecosystem resilience. Full article

Pig slurry fertigation can modify soil biochemical properties by promoting glomalin production and shifting microbial communities; however, its impacts under varying water regimes remain insufficiently quantified. We assessed irrigated and rainfed systems by integrating the soil quality index (SQI) with total and easily extractable glomalin (T-GRSP, EE-GRSP), determining microbial diversity via eDNA amplicon sequencing, and evaluating enzyme activities across three soil depths (0–10, 10–20, and 20–30 cm). Robust regression revealed that T-GRSP and EE-GRSP accounted for 75% of the SQI variability in irrigated soils and 46% in rainfed soils (p < 0.001), with the strongest correlations in the 0–10 cm layer. Irrigation increased T-GRSP concentrations by 66% (1.78 vs. 1.07 mg g⁻¹) and raised its contribution to total soil carbon from 2.0% to 3.2%. The EE-GRSP levels were slightly lower in the irrigated soils (0.73 vs. 0.76 mg g⁻¹) yet remained a sensitive early-warning indicator of moisture stress in rainfed plots. Microbial profiling showed a 19% increase in Shannon bacterial diversity (3.44 vs. 2.89), even more bacterial communities under irrigation, intermediate fungal diversity, higher fungal abundance, and no detectable arbuscular mycorrhizal fungi in either system. Combining GRSP fractions with microbial and enzymatic markers provides a responsive framework for assessing soil health and guiding organic amendment strategies in fertigation-based agriculture under fluctuating water availability. Full article

The remediation of lead (Pb)-contaminated soils through eco-friendly strategies is critical for sustainable agriculture. This study investigated the role of arbuscular mycorrhizal fungi (AMF) in enhancing maize tolerance to Pb stress and modulating rhizosphere microbial communities. A pot experiment was conducted with maize (Baiyu833) under four Pb concentrations (0, 900, 1800, 2700 mg·kg⁻¹) and three AMF treatments: non-inoculation (Non), Funneliformis mosseae (Fm), or Rhizophagus intraradices (Ri). The results demonstrated that AMF inoculation significantly increased plant biomass, boosted antioxidant enzyme activities (SOD, POD), and reduced malondialdehyde (MDA) levels, mitigating Pb-induced oxidative stress. AMF restricted Pb translocation to aerial parts, with root Pb accumulation reaching 2110.76 mg·kg⁻¹ (Fm) and 2090.56 mg·kg⁻¹ (Ri) under Pb2700, enhancing phytostabilization. High-throughput sequencing revealed that AMF inoculation enriched α-diversity indices and restructured bacterial communities, favoring beneficial taxa like Promicromonospora, which are linked to heavy metal resistance and plant growth promotion. Principal coordinate analysis highlighted distinct clustering of microbial communities driven by AMF, emphasizing their role in alleviating Pb toxicity. These findings underscore that AMF enhance maize resilience to Pb by regulating antioxidant defense, immobilizing Pb in roots, and recruiting stress-tolerant rhizosphere microbiomes. This study provides insights into AMF-assisted phytoremediation as a sustainable strategy for Pb-contaminated soils. Full article

Mofettes or natural CO₂ springs release large amounts of geogenic CO₂ at ambient temperature, leading to long-term soil hypoxia in these extreme ecosystems. Thus, they can serve as natural long-term experiments in ecology and evolution and other environmental studies, providing stable long-term changes in abiotic factors that are most pronounced in mofette soils. This paper reviews basic research on rhizosphere processes, soil microbial communities, and microbial diversity in mofettes, focusing on reports describing the effects of altered soil gas regimes on root respiration and the diversity and community structure of archaea, bacteria, and fungi in soil. Furthermore, an insight into possible applications of mofette ecosystems is given. For more than 20 years, mofettes have provided new insights into the importance of long-term changes in abiotic environmental factors in regulating soil biodiversity, serving as a model for extreme ecosystems. Mofettes provide an innovative approach to the study of many ecological processes that occur slowly and, therefore, require extensive and lengthy observations and experiments, acting as a space-for-time substitution. Previous studies in mofettes around the world have determined plant responses to elevated CO₂ concentrations over multiple generations, described new species of collembolans and yeasts, and identified stable patterns in microbial communities describing specific acidophilic and methanogenic consortia of soil archaea and bacteria, as well as stable communities of plant symbiotic arbuscular mycorrhizal fungi. As the development of high-throughput molecular techniques has accelerated rapidly in the last decade, mofettes now serve more than ever as a natural long-term experimental system to study soil and rhizosphere ecology and contribute to further research on long-term ecological and evolutionary processes that are crucial for understanding past evolutionary events, managing future ecosystems, and predicting ecological responses to global change. Some recent developments target the specific geological and biological characteristics of these extreme ecosystems, including in terms of applications related to environmental impact assessment of carbon capture and storage systems, as well as conservation status, tourism, culture and education, i.e., broader ecosystem services of mofettes, which are addressed in this review together with basic research on soil biodiversity. Full article

Arbuscular mycorrhizal fungi (AMF) and Trichoderma spp. (T) are known as plant-beneficial fungi effective against root-knot nematodes, but their interactions in the rhizosphere are not well understood. This study examined how Meloidogyne javanica influences AMF colonization and community diversity at the root-soil interface of tomato plants. A 60-day growth chamber experiment was conducted with tomato plants grown in non-sterile agricultural soil, either infected or not with M. javanica, that received a single inoculation with AMF or Trichoderma (strains T363 or TJ15), combined AMF + T inoculations, or no inoculation (Control). Both single and combined inoculations significantly reduced root galls, eggs, and soil nematode larvae. An AMF community analysis via single-strand conformation polymorphism of the D1 region of 28S rDNA gene (Glomeraceae family) revealed that M. javanica decreased AMF diversity and altered community structure, in plants single-inoculated with AMF. However, a combined inoculation with Trichoderma appears to prevent this reduction and maintain AMF diversity. While M. javanica reduced root mycorrhizal colonization, it did not affect Trichoderma abundance. These results suggest that Trichoderma may be more resilient to nematode infection, helping stabilize AMF communities and enhance biocontrol. Thus, combining AMF and Trichoderma inoculations could better preserve root health and improve biological control effectiveness against M. javanica. Full article

This study aimed to investigate the effect of the association of Lotus tenuis with arbuscular mycorrhizal fungi (AMF) on its development under high defoliation intensity or partial submergence in a P-deficient soil of the Salado River Basin in a pot experiment. L. tenuis mycorrhizal plants showed higher tolerance to partial submergence (91%) than to high defoliation intensity (57%). Shoot biomass was the highest in mycorrhizal non-stressed and submerged plants (11.71 g and 12.06 g, respectively), and decreased by 38% in defoliated plants. Both stress conditions caused a negative effect on root growth of plants with or without AMF. High-intensity defoliation can be considered the most stressful scenario for mycorrhizal L. tenuis plants and AMF play a more marked role in P nutrition. Under submergence, AMF caused a net effect on L. tenuis growth, improving carbon and P resource distribution to sustain shoot growth and elongation. Root AMF colonization and nodulation decreased under submergence. High arbuscular colonization percentages were reached under both stress conditions, indicating that the symbiosis may be functional. L. tenuis roots can act as a reservoir of the fungal community under severe stress conditions, allowing the preservation of the AMF inoculum. Full article

Rice serves as the staple food for half of the world’s population. Given the expanding global population, the urgency to allocate land for rice cultivation is paramount. In Northeast China, saline–sodic and black soils represent two distinct soil types used in rice production. During rice growth, soil microorganisms, including arbuscular mycorrhizal fungi (AMF), play pivotal roles in nutrient uptake and resistance to biotic and abiotic stressors. While numerous studies have elucidated the role of AMF in enhancing rice growth and its adaptation to stress, the differences in AMF communities within paddy fields between different soil types have been largely overlooked. In this study, high-throughput sequencing technology was employed to analyze the diversity and community structure of AMF, and metagenomic sequencing was employed to analyze AMF functional gene differences between the two soil types (black and saline–sodic soils). At the same time, the commonalities and differences of the soil characteristics (nitrogen, phosphorus, potassium, pH, etc.) were verified in influencing AMF communities. The results indicated that Glomus was the predominant genus in both soil types, followed by Paraglomus. The overall abundance of AMF was higher at the heading stage than at the harvest stage, with Paraglomus showing greater adaptation to the saline–sodic soil environment. Total phosphorus (TP) was identified as the primary factor influencing AMF diversity at the heading stage. In the harvest stage, AMF community diversity was greater in saline–sodic paddy soil compared to black soil, a reversal from the heading stage. Further analysis of the functional genes of Rhizophagus intraradices revealed that gene activity in the heading stage of saline soils significantly surpassed that in black soils, suggesting that R. intraradices plays a more crucial role in saline environments. Additionally, spore density and the content of easily extractable glomalin-related soil protein were relatively higher in saline–sodic soil than in black soil. Thus, it may be inferred that AMFs are more vital in saline–sodic soils than in black soils of the paddy fields in Northeast China. This study may offer valuable insights into the utilization of AMF in paddy fields in Northeast China. Full article

Arbuscular mycorrhizal (AM) fungi occur in the interface between soils and plants. Yet, the impacts of the plant community functional composition and soil properties on AM fungal communities remain poorly understood in the face of ongoing climate change. Here, we investigated the AM fungal community in alpine meadow habitats of the Tibetan Plateau by linking fungal species richness to plant community functional composition and soil parameters at three latitudinal sites. High-throughput sequencing of the AM fungal small subunit rRNA gene was performed to characterize fungal communities. We found that AM fungal diversity and plant functional diversity, as well as the contents of soil nutrients, were significantly higher in the southernmost site, Hongyuan (HY). Total soil nitrogen and soil-available phosphorus explained the variation in AM fungal diversity, while AM fungal biomass was best predicted by the plant community-weighed mean nitrogen:phosphorus ratio (CWM-N:P). Glomus species preferentially occurred in the northernmost site of Hezuo (HZ). Distance-based redundancy analysis (db-RDA) revealed that AM fungal community structure was influenced by not only CWM-N:P but also by plant community-weighed mean photosynthetic rate (CWM-Pn), soil total carbon, and plant community functional dispersion (FDis). We conclude that plant traits and soil properties are crucial for nutrient–carbon (C) exchange, as fungal symbionts may shape AM communities in this vast alpine meadow ecosystem. Our findings provide timely insight into AM fungal community assembly from the perspective of nutrient–C exchange dynamics in the Tibetan Plateau’s alpine meadow habitats. Full article

The overuse of chemical fertilizers not only leads to resource wastage but also causes problems such as environmental pollution and soil degradation. In particular, crop growth in saline–sodic soils is severely restricted due to high salinity and alkalinity, further exacerbating challenges in agricultural production. The aim of this study was to investigate different fertilization strategies that combine chemical fertilizer reduction with arbuscular mycorrhizal fungi (AMF) for improving saline–sodic soils and to assess the effects of these protocols on crop yield, soil properties, and microbial communities. Field experiments across two sites (BeiWuLao and XuJiaZhen) demonstrated that integrating AMF with CF reduction (AHCF treatment) significantly enhanced maize yield by 23.5% at BeiWuLao (from 11,475 to 14,175 kg/ha) and 81.2% at XuJiaZhen (from 7245 to 13,125 kg/ha) compared to conventional fertilization (CK) (p < 0.01). Soil nutrient analysis revealed substantial improvements: available potassium (AK) increased by 77.7% (61.35 vs. 39.33 mg/kg), available phosphorus (AP) by 33.9% (20.50 vs. 15.50 mg/kg), ammonium nitrogen (AN) by 57.3% (64.17 vs. 40.83 mg/kg), and soil organic matter (SOM) by 96.4% (46.98 vs. 23.91 mg/kg) under AHCF treatment (p < 0.05). Although pH and electrical conductivity (ECe) remained unaffected, AMF inoculation shifted microbial composition, elevating salinity-tolerant taxa such as Actinobacteria (+24.7%) and Anabaena. Beta diversity analysis (PCoA) confirmed distinct microbial community structures between treatments, with ECe and AN identified as primary drivers of bacterial (RDA variance: 74.08%) and fungal (RDA variance: 54.63%) communities, respectively. Overall, the combination of chemical fertilizer reduction and AMF effectively improved soil fertility, microbial community structure, and crop yield. These findings have important implications for improving saline soils and promoting environmental sustainability. Full article