Diversity Of Mycorrhizal Fungi Research Articles

Influence of Potentially Toxic Elements and Physio-Chemical Parameters of Industrially Contaminated Soil on Arbuscular Mycorrhizal Fungal Diversity in BBN Corridor, Himachal Pradesh, India

ABSTRACT Arbuscular mycorrhizal fungi (AMF) play an essential role in plant growth and have great potential to enhance plant tolerance under polluted and toxic conditions. This study deals with a survey of five contaminated sites of the Baddi Barotiwala Nalagarh (BBN) industrial corridor/hub to investigate the morpho-diversity of endotrophic AM fungi associated with native plants. The high contamination factor of Cd and Fe in different study sites revealed a high intensity of contamination, indicating that the sites were significantly polluted with Cd and Fe. Results showed that AM symbioses were successfully established in the roots of native plants, highlighting their role in mitigating the harmful effects of potentially toxic elements (PTEs) through bioremediation. A total of 50 AMF morphotypes across 9 genera (Acaulospora, Entrophospora, Ambispora, Diversispora, Gigaspora, Scutellospora, Glomus, Rhizophagus, and Sclerocystis) were identified, with Glomeraceae being the most abundant (46%), followed by Acaulosporaceae (39%) and others contributing less (15%). The study also indicated that the hyphal and vesicular infections were prominent than arbuscular infections in roots. This is the first report on the diversity of native and putative AMF species associated with plants in the BBN industrial corridor, suggesting that these fungi could be cultured for further use as a sustainable organic approach in agriculture and rehabilitation practices in polluted areas.

Arbuscular mycorrhizal fungal inoculum and N2-fixing plants in ecological reclamation of arid mining areas: nutrient limitation of the moss biocrust microbiome.

Ecoenzymatic stoichiometry can reflect the ability of soil microorganisms to acquire energy and nutrients and to determine their response to environmental stresses. However, the drivers of metabolic limitation of the moss biocrust microbiome during the ecological restoration of coal mining areas are poorly understood. Therefore, in this study, enzymatic stoichiometry modeling and high-throughput sequencing were used to simultaneously determine moss biocrust microbial metabolic limitation and its relationship with moss biocrust nutrients and arbuscular mycorrhizal fungal (AMF) diversity in five arid and semi-arid revegetation types (Hippophae rhamnoides, Amorpha fruticosa, Cerasus humilis, Cerasus szechuanica, and Xanthoceras sorbifolium) and two microbial treatments (AMF-inoculated and uninoculated). The activities of moss biocrust carbon (C)-, nitrogen (N)-, and phosphorus (P)-acquiring enzymes and organic carbon fractions in the AMF-inoculated treatment were significantly higher than those in the uninoculated control. Moss biocrust microbial community C and P limitations were observed in the five revegetation types, with lower limitation in general in the AMF-inoculated treatment. Dinitrogen-fixing plants (Amorpha fruticosa and Hippophae rhamnoides) significantly mitigated moss biocrust microbiome C and P limitation, especially in the AMF-inoculated treatment. Furthermore, partial least squares path modeling (PLS-PM) shows that moss biocrust organic carbon fractions (- 0.73 and - 0.81 of the total effects, respectively) and AMF diversity (- 0.73 and - 0.81 of the total effects) had negative effect on microbial C and P limitation, suggesting that more efficient active nutrients and AMF diversity are important factors alleviating limitation of moss biocrust microbial metabolism. This indicates that moss biocrust microbial communities under N2-fixing species with AMF inoculation were more stable under environmental stress; thus, AMF inoculation and/or N2-fixing plants may be recommended as preferred options for the ecological restoration of arid mining areas.

Ecology of arbuscular mycorrhizal association in coconut (Cocos nucifera L.) palms: Analysis of factors influencing AMF in fields

This study is the first thorough ecological analysis of arbuscular mycorrhizal fungal (AMF) diversity in randomly selected traditional coconut fields across Kerala, South India. We conducted a critical analysis of AMF diversity, percentage root length colonization (PRLC), and mean spore density (MSD) across 248 sites, taking into account variations in plant, environmental, and soil factors like coconut varieties, palm health conditions, agroclimatic zones, soil types, and seasons in the region. A total of 23 AMF species from seven genera (Acaulospora, Archaeospora, Funneliformis, Glomus, Sclerocystis, Septoglomus, and Scutellospora) were identified, with Acaulospora scrobiculata being the dominant species in all studied fields. A critical analysis of diversity indices, including the Shannon-Weiner Index, Simpson's diversity index, and Gini-Simpson index, concerning variables indicated that soil series influences AMF diversity in specific fields. Correlational and principal component analyses highlighted the interrelationships between specific soil types and quality parameters affecting AMF characteristics, underscoring their crucial role in coconut palm growth. The study also revealed the ecological amplitudes of indigenous AMF species related to specific soil fertility parameters. Overall, this research serves as a model for identifying root- and soil-specific AMF in agricultural fields and provides valuable ecological insights for utilizing indigenous AMF species as ecotechnological tools for sustainable coconut cultivation.

Arbuscular mycorrhizal fungal diversity in agricultural fields is explained by the historical proximity to natural habitats

Soil microbes are essential to maintain terrestrial ecosystem functionality. However, their diversity is threatened by land-use change, such as agricultural expansion and intensification. One important microbial group mediating the exchange of nutrients between plants and soil is arbuscular mycorrhizal (AM) fungi. The response of microorganism diversity to present and past habitat amount has been poorly studied. Here, we evaluate the potential role of current and historical natural habitat availability in explaining the diversity of AM fungi in arable fields. We conducted a spatially intensive sampling of three agricultural fields in Estonia. Soil AM fungal diversity was determined by soil DNA metabarcoding. We related AM fungal species richness, along with beta diversity components (turnover and nestedness), to abiotic conditions and natural habitat area availability at different spatial scales and time periods. Our findings showed a positive relationship between AM fungal richness and the amount of natural habitat area. Specifically, current AM fungal species richness was best explained by the amount of natural habitat from 130 years earlier, indicating a legacy effect of past land use on current soil biodiversity. The amount of past natural areas was negatively related to the beta diversity turnover component, indicating a replacement of AM fungal species in disturbed sites. While biodiversity-friendly farming is useful in promoting diverse soil biota, historical legacies can be persistent. Maintaining natural habitats around agricultural fields can further promote soil AM fungal diversity for future generations.

Diversified Cover Crops and No-Till Enhanced Soil Total Nitrogen and Arbuscular Mycorrhizal Fungi Diversity: A Case Study from the Karst Area of Southwest China

The deteriorating soil health under continuous monoculture is commonly found across various cropping systems. This study evaluated the effects of different tillage practices (conventional tillage and no till) and species mixtures (legumes and grasses) on arbuscular mycorrhizal fungi (AMF) community properties, soil nutrients, and enzyme activity in a 3-year experiment. Compared with traditional tillage, the number of AMF species under no-till conditions was increased, with the Glomus group being dominant. Under different tillage conditions, TN (total N) and AN (available N) contents under no till were significantly higher than those under conventional tillage, while no significant differences among other nutrients were found. The activities of soil acid phosphatase (S-ACP), soil dehydrogenase (S-DHA), and soil sucrose (S-SC) under conventional tillage were significantly higher than those under no till, and the cover crop mixtures also had an exclusive advantage in yield. Soil organic matter (SOM) indicated a significant negative correlation with glomalin-related soil protein (GRSP). The increase in diversity associated with the AMF species community was strongly correlated with the increase in three enzyme activities, and AN was negatively correlated with all species. Tillage did not significantly change soil chemistry, except for AN, and the high concentration of AN led to a decrease in AMF species. The results of this study showed that no till was an effective measure for enriching soil micro-organism population. Additionally, soil AMF diversity was improved by cover crop mixtures, and microbial diversity was higher than that under monoculture cover crops. Different AMF groups responded differently to tillage and cover crop mixtures. Across all mixtures, the combination of hairy vetch (Vicia villosa R.) and ryegrass (Lolium perenne L.) performed the best.

Arbuscular mycorrhizal fungal diversity and potential association networks among African tropical forest trees.

Tropical forests represent one of the most diverse and productive ecosystems on Earth. High productivity is sustained by efficient and rapid cycling of nutrients, which is in large part made possible by symbiotic associations between plants and mycorrhizal fungi. In these associations, an individual plant typically associates simultaneously with multiple fungi and the fungi associate with multiple plants, creating complex networks among fungi and plants. However, there are few studies that have investigated mycorrhizal fungal composition and diversity in tropical forest trees, particularly in Africa, or that assessed the structure of the network of associations among fungi and trees. In this study, we collected root and soil samples from Ise Forest Reserve (Southwest Nigeria) and used a metabarcoding approach to identify the dominant arbuscular mycorrhizal (AM) fungal taxa in the soil and associating with ten co-occurring tree species to assess variation in AM communities. Network analysis was used to elucidate the architecture of the network of associations between fungi and tree species. A total of 194 Operational Taxonomic Units (OTUs) belonging to six AM fungal families were identified, with 68% of all OTUs belonging to Glomeraceae. While AM fungal diversity did not differ among tree species, AM fungal community composition did. Network analyses showed that the network of associations was not significantly nested and showed a relatively low level of specialization (H2 = 0.43) and modularity (M = 0.44). We conclude that, although there were some differences in AM fungal community composition, the studied tree species associate with a large number of AM fungi. Similarly, most AM fungi had great host breadth and were detected in most tree species, thereby potentially working as interaction network hubs.

Reduced tillage intensity does not increase arbuscular mycorrhizal fungal diversity in European long‐term experiments

AbstractMechanical soil disturbance is one among the key factors influencing soil biodiversity in agriculture. Although many soil organisms are sensitive to soil disturbance, fungi could be highly impacted due to their sessile lifestyle, relatively slow growth and filamentous body structure. Arbuscular mycorrhizal (AM) fungi are of particular interest in arable lands, providing crop plants with numerous vital services such as nutrient acquisition and protection against abiotic and biotic stressors. Considering this, tillage practices that aim to reduce soil disturbance are often seen as a fungal‐friendly alternative to conventional inversion tillage. Although local studies exist on the impacts of minimal tillage practices on AM fungi, the universality of this approach has been debated. Our objective was to assess the effects of reduced tillage intensity on AM fungi in comparison with conventional tillage. Using high‐throughput sequencing techniques in long‐term field experiments in five European countries, we show that the effects of reduced tillage intensity may not necessarily be positive on soil AM fungal diversity. Plots which were tilled using reduced tillage techniques had lower AM fungal richness in three countries, whereas in one of them, no significant differences were found. We also observed a shift in AM fungal communities where prevalence of taxa preferring root colonisation rather than soil exploration increased under reduced tillage regimes. Here, we argue that more detailed and long‐term studies are needed to understand the factors that could make the reduction of soil disturbance more beneficial to AM fungi if agricultural sustainability goals are to be met.

Changes in climatic conditions drive variations in arbuscular mycorrhizal fungi diversity and composition in semi-arid oak forests

Changes in climatic conditions drive variations in arbuscular mycorrhizal fungi diversity and composition in semi-arid oak forests

Drivers of Arbuscular Mycorrhizal Fungal Diversity Across 1,000 km of Chilean Vineyards

Drivers of Arbuscular Mycorrhizal Fungal Diversity Across 1,000 km of Chilean Vineyards

Interplay of soil characteristics and arbuscular mycorrhizal fungi diversity in alpine wetland restoration and carbon stabilization.

Alpine wetlands are critical ecosystems for global carbon (C) cycling and climate change mitigation. Ecological restoration projects for alpine grazing wetlands are urgently needed, especially due to their critical role as carbon (C) sinks. However, the fate of the C pool in alpine wetlands after restoration from grazing remains unclear. In this study, soil samples from both grazed and restored wetlands in Zoige (near Hongyuan County, Sichuan Province, China) were collected to analyze soil organic carbon (SOC) fractions, arbuscular mycorrhizal fungi (AMF), soil properties, and plant biomass. Moreover, the Tea Bag Index (TBI) was applied to assess the initial decomposition rate (k) and stabilization factor (S), providing a novel perspective on SOC dynamics. The results of this research revealed that the mineral-associated organic carbon (MAOC) was 1.40 times higher in restored sites compared to grazed sites, although no significant difference in particulate organic carbon (POC) was detected between the two site types. Furthermore, the increased MAOC after restoration exhibited a significant positive correlation with various parameters including S, C and N content, aboveground biomass, WSOC, AMF diversity, and NH4+. This indicates that restoration significantly increases plant primary production, litter turnover, soil characteristics, and AMF diversity, thereby enhancing the C stabilization capacity of alpine wetland soils.

Tree and mycorrhizal fungal diversity drive intraspecific and intraindividual trait variation in temperate forests: Evidence from a tree diversity experiment

Abstract The study of tree species coexistence is crucial to understand the assembly of forest communities. In this context, trees adjust their traits in response to the interactions with other trees and, specifically, as a result of the competition for resources. Further, mycorrhizal fungal diversity and associations are important drivers of ecosystem functioning in forests, but their role as drivers of intraspecific trait variation has been disregarded. Here, we studied intraspecific trait variation of trees in response to tree and mycorrhizal fungal diversity. We sampled 3200 leaves from 640 trees belonging to 10 native, deciduous species in a tree diversity experiment in Central Germany. This experiment relies on the combination of gradients of tree richness and mycorrhizal associations. To handle large amounts of leaf samples, we acquired leaf‐level spectral data and used deep learning to predict values for five leaf traits from the leaf economics spectrum (LES): specific leaf area, leaf dry matter content, carbon to nitrogen ratio, carbon content and phosphorus content. For every tree, we calculated the mean value for every trait and two multi‐trait functional indices (functional richness and functional dispersion) based on values for individual leaves. Finally, we used sequencing‐based data to assess the richness of mycorrhizal fungi associated with the trees. We found that tree and mycorrhizal fungi richness had an effect on different leaf functional traits. Specifically, tree richness positively affected specific leaf area and, additionally, had a negative effect on the functional indicies, which revealed that the phenotypic diversity within the tree crown decreased with tree species richness. In addition, leaf carbon to nitrogen ratio decreased with increasing arbuscular mycorrhizal fungal richness in both arbuscular and ectomycorrhizal tree species. Finally, we did not find differences between arbuscular and ectomycorrhizal trees regarding their location within the LES. Our results suggest that trees modify their strategy in response to local tree diversity, not only by shifting trait values but also by shifting the variability intraindividually. In addition, higher mycorrhizal fungal diversity does not seem to lead to higher complementarity, but instead, tree and mycorrhizal fungi affect different aspects of leaf traits. Read the free Plain Language Summary for this article on the Journal blog.

Arbuscular mycorrhizal fungal diversity associated with an endangered species, Chamaecyparis formosensis, in the nature habitat

Arbuscular mycorrhizal fungal diversity associated with an endangered species, Chamaecyparis formosensis, in the nature habitat

Dosage and exposure time effects of two micro(nono)plastics on arbuscular mycorrhizal fungal diversity in two farmland soils planted with pepper (Capsicum annuum L.)

As emerging environmental pollutants, micro(nano)plastics (MPs) like polyethylene terephthalate (PET) and low-density polyethylene (LDPE) have adverse effects on terrestrial biota and ecosystem function. However, the performance and roles of soil arbuscular mycorrhizal (AM) fungi in MPs-contaminated vegetable fields are poorly understood. Thus, a 120-day pot experiment was conducted to test the impacts of two input levels of either PET (~13 μm) or LDPE (~500 nm) on AM fungal diversity and pepper (Capsicum annuum L.) growth in two farmland soils collected from Nanjing (NJ) and Chongqing (CQ), respectively. In the vast majority of cases, 1 % rather than 0.1 % of both MPs greatly decreased the observed richness, Shannon and Simpson's indices, and Pielou's evenness of AM fungi, and decreased mycorrhizal colonization, root and shoot biomasses, fruit yield, and leaf superoxide dismutase, peroxidase, and catalase activities of pepper, while increased leaf malondialdehyde content. From day 40 to 120, the inhibition of either diversity or vitality of AM fungi by 1 % and 0.1 % of MPs gradually increased and weakened, respectively. Compared with PET, LDPE with substantially smaller particle size was more toxic to mycorrhization at day 40, but no longer at day 120. Almost all plant parameters significantly correlated to mycorrhizal colonization, which significantly correlated to both Shannon and Simpson's indices of AM fungi, and soil pH, available P and K concentrations, and alkaline phosphatase activity. All diversity indices of AM fungi clearly negatively correlated to soil pH from 4.4 to 5.6 for the NJ soil and from 5.3 to 6.5 for the CQ soil, and also positively to mineral N and negatively to available P concentrations for the NJ and CQ soils, respectively. Thus, the study emphasized that high input of MPs significantly inhibited soil AM fungal diversity and vitality and thereby vegetable growth via changing soil pH and major nutrient availability.

Diversity of Mycorrhizal Fungi in Temperate Orchid Species: Comparison of Culture-Dependent and Culture-Independent Methods.

Many orchid species are endangered due to anthropogenic pressures such as habitat destruction and overharvesting, meanwhile, all orchids rely on orchid mycorrhizal fungi (OMF) for seed germination and seedling growth. Therefore, a better understanding of this intimate association is crucial for orchid conservation. Isolation and identification of OMF remain challenging as many fungi are unculturable. In our study, we tested the efficiency of both culture-dependent and culture-independent methods to describe OMF diversity in multiple temperate orchids and assessed any phylogenetic patterns in cultivability. The culture-dependent method involved the cultivation and identification of single pelotons (intracellular hyphal coils), while the culture-independent method used next-generation sequencing (NGS) to identify root-associated fungal communities. We found that most orchid species were associated with multiple fungi, and the orchid host had a greater impact than locality on the variability in fungal communities. The culture-independent method revealed greater fungal diversity than the culture-dependent one, but despite the lower detection, the isolated fungal strains were the most abundant OMF in adult roots. Additionally, the abundance of NGS reads of cultured OTUs was correlated with the extent of mycorrhizal root colonization in orchid plants. Finally, this limited-scale study tentatively suggests that the cultivability character of OMF may be randomly distributed along the phylogenetic trees of the rhizoctonian families.

Assessing above and belowground recovery from ammonium sulfate addition and wildfire in a lowland heath: mycorrhizal fungi as potential indicators

Atmospheric pollution containing soil‐nitrifying ammonium sulfate ((NH₄)₂SO₄) affects semi‐natural ecosystems worldwide. Long‐term additions of (NH₄)₂SO₄ to nitrogen (N)‐limited habitats, including heathlands, increase climate stress affecting recovery from wildfires. Although heathland vegetation largely depends on ericoid mycorrhizal fungi (ErM) to access soil N, we lack detailed understanding of how prolonged exposure to (NH₄)₂SO₄ may alter ErM community composition and host plants' reliance on fungal partners following wildfire and affect recovery. Simulation of atmospheric pollution ((NH₄)₂SO₄) occurred bi‐weekly for 5 years after a 2006 wildfire in a UK heathland. Ten years after treatments ceased, we measured vegetation structure, lichen and lichen photobiont composition, soil characteristics, ErM colonization, ErM diversity in roots and soil, and assessed ErM potential as novel recovery indicators. Heather height and density, and moss groundcover, were greater in N‐enriched plots. Lichen community indices showed significant treatment effects, but without differences in photobionts. Soil pH and Mg were significantly lower in treated plots while soil cation exchange capacity was significantly higher. There were no detectable differences in ErM composition and keystone ErM taxa between control and treated plots. Soil carbon stock measures were variable. Our results indicate atmospheric pollution following fire can have significant lingering effects above‐ and belowground. ErM diversity and root colonization were not assessed in the original N‐addition experiment; we advocate for their inclusion in future studies as an integral part of the recovery assessment toolkit. We show that mycorrhizal fungi diversity is a viable ecological tool and summarize key steps for ErM identification.

Mycorrhizal communities of Vanilla planifolia in an introduction area (La Réunion) under varying cultivation practices

Societal Impact StatementVanilla is one of the most valuable spices in the world. In Madagascar and La Réunion, the world's leading producers, vanilla is of great economic and cultural importance. Like all orchids, vanilla plants associate with mycorrhizal fungi in their roots forming mutualistic associations that allow them to grow and thrive. Understanding the diversity of mycorrhizal fungi adapted to vanilla cultivation, particularly in the Indian Ocean islands where they have never previously been studied, is becoming a necessity for maintaining vanilla crops in these regions in the face of climate change and the emergence of new pathogens.Summary The vanilla orchid (Vanilla spp.) is one of the most valuable cultivated plants worldwide. As with all orchids, vanillas form mycorrhizal associations with fungi in their roots, but their fungal partners have not been investigated outside their native geographic range in Central America. We investigated the whole fungal and mycorrhizal associations in cultivated vanilla (Vanilla planifolia) by sequencing the fungal ITS‐2 marker in the terrestrial and aerial roots using a metabarcoding approach. We selected plants cultivated in three conditions (i.e., cultivation under shade house, in openfield, or in the understory) in one locality of La Réunion island (Indian Ocean) and tested for a possible effect of cultivation practices on fungal communities. Cultivated vanillas in La Réunion mainly associate with Tulasnellaceae (75 OTUs) and Ceratobasidiaceae (8 OTUs). Among the seven most abundant Tulasnellaceae, six are similar to fungi detected in the roots of cultivated vanillas in Central America or in the roots of native orchids in La Réunion. Cultivation practices impacted both total fungal and mycorrhizal community compositions with no clear effect on fungal richness. Notably, Tulasnellaceae and Ceratobasidiaceae were scarce in aerial roots, except in the traditional cultivation in the forest understory. These results shed light on the geographical origins of mycorrhizal fungi of cultivated vanillas in La Réunion and show that they form a pool of both locally and globally distributed fungal partners. These mycorrhizal communities vary according to cultivation practices, and their potential roles in plant nutrition and resistance against pathogens await further attention.

Moderate input of nanoscale zero-valent iron accelerated soil polychlorinated biphenyls dissipation with limited inhibition on arbuscular mycorrhizal fungal diversity

Moderate input of nanoscale zero-valent iron accelerated soil polychlorinated biphenyls dissipation with limited inhibition on arbuscular mycorrhizal fungal diversity

Root exudation under maize/soybean intercropping system mediates the arbuscular mycorrhizal fungi diversity and improves the plant growth.

Maize/soybean intercropping is a common cropping practice in Chinese agriculture, known to boost crop yield and enhance soil fertility. However, the role of below-ground interactions, particularly root exudates, in maintaining intercropping advantages in soybean/maize intercropping systems remains unclear. This study aimed to investigate the differences in root exudates between intercropping and monocropping systems through two pot experiments using metabolomics methods. Multiple omics analyses were conducted to explore correlations between differential metabolites and the community of Arbuscular Mycorrhizal Fungi (AMF), shedding light on the mechanisms underlying the dominance of intercropping from the perspective of root exudates-soil microorganism interactions. The study revealed that intercropping significantly increased the types and contents of root exudates, lowered soil pH, increased the availability of nutrients like available nitrogen (AN) and available phosphorus (AP), and enhanced AMF colonization, resulting in improving the community composition of AMF. Besides, root exudates in intercropping systems differed significantly from those in monocropping, with 41 and 39 differential metabolites identified in the root exudates of soybean/maize, predominantly amino acids and organic acids. The total amount of amino acids in the root exudates of soybean intercropping was 3.61 times higher than in monocropping. Additionally, the addition of root exudates significantly improved the growth of soybean/maize and AMF colonization, with the mycorrhizal colonization rate in intercropping increased by 105.99% and 111.18% compared to monocropping, respectively. The identified metabolic pathways associated with root exudates were closely linked to plant growth, soil fertility improvement, and the formation of AMF. Correlation analysis revealed a significant relationship (P < 0.05) between certain metabolites such as tartaric acid, oxalic acid, malic acid, aspartic acid, alanine, and the AMF community. Notably, the photosynthetic carbon fixation pathway involving aspartic acid showed a strong association with the function of Glomus_f_Glomerace, the dominant genus of AMF. A combined analysis of metabolomics and high throughput sequencing revealed that the root exudates of soybean/maize intercropping have direct or indirect connections with AMF and soil nutrients. This suggests that the increased root exudates of the soybean/maize intercropping system mediate an improvement in AMF community composition, thereby influencing soil fertility and maintaining the advantage of intercropping.

Assessment of Mycorrhizal Fungal Diversity in Legumes (Medicago sativa, Medicago truncatula and Trifolium rubens) from Algeria and Their Influence on Soil Physicochemical and Microbiological Properties

Background: Medicago sativa, Medicago truncatula and Trifolium rubens are legumes widely distributed in Algeria. These species hold ecological and agricultural significance and serve as a natural resource for combating desertification and as livestock fodder. Methods: Comparative investigations of arbuscular mycorrhizal fungi (AMF) colonization in the roots of these leguminous species were conducted. The physicochemical and microbiological attributes of AMF’s infectious potential were explored for all three species. The presence or absence of endomycorrhizal structures was assessed in these species. Result: The mycorrhizal infectious potential of the flora was significantly enhanced in the case of Medicago truncatula when compared to Trifolium rubens. Mycorrhization occurred at a frequency exceeding 80% in all three species. The impact of legume mycorrhizal fungi colonization on soil physicochemical properties was examined, revealing alterations in soil biological fertility, particularly in terms of phosphate and nitrogen content. Medicago truncatula exhibited a more pronounced positive influence on soil physical, chemical and microbiological characteristics when compared to Medicago sativa and Trifolium rubens. Consequently, these herbaceous species can be employed as nurse plants (facilitators) or as bio-fertilizers.

Diversity of Mycorrhizal fungi in Eastern Hemlock stands will significantly change with the effects of Hemlock Woolly Adelgid infestation in southwestern Nova Scotia, Canada

A foundation tree species, eastern hemlock (Tsuga canadensis) is threatened by the invasive hemlock woolly adelgid (Adelges tsugae) (HWA) in southwestern Nova Scotia, Canada. The loss of this key species and its heavily shaded ecosystems may alter the diversity of important mycorrhizal fungi in hemlock forests. Mycorrhizal fungi share a vital mutualistic relationship with their host trees; consequentially, understanding if and how the predicted eastern hemlock decline will affect mycorrhizal diversity is paramount. Using available literature, we discuss three major consequences of HWA on eastern hemlock ecosystems – changing forest composition, loss of old-growth trees, and increased insect stress on host trees – and how they will likely influence mycorrhizal communities as adelgid infestations intensify. Environmental variables are also discussed as another major influence on fungal diversity. We conclude that the mycorrhizal community of eastern hemlock forests will likely change significantly as old-growth hemlock is replaced with mixed forest. We also suggest that mycorrhizal community composition will shift in favour of generalist mycorrhizae which form symbioses with multiple tree species. These conclusions illuminate the future of hemlock forest fungi in southwestern Nova Scotia and underline the importance of conserving old-growth eastern hemlock forests and their unique fungal communities.