The effect of wild ungulate density on ecosystems varies according to different factors: climate and physiography conditions, forest type, management history, and herbivore identity. In this study, ...we evaluated the effect of historically high densities of red deer (Cervus elaphus L.) on the soil fungal communities in Mediterranean ecosystems using 30 paired plots, open on the one hand and exclosure plots on the other one. Plots were established at the end of 2020 in a perimeter-fenced hunting estate of 6600 ha in Toledo, Spain. Three months after plots were established, we analysed fungal communities in 60 soil samples using Illumina 250-bp paired-end sequencing. We estimated changes in total fungal richness and in the richness of trophic groups through Linear Mixed Effects models using fenced/unfenced type and deer habitat use as fixed variables and the location of the plots and the main tree host species as random variables. Fungal composition was analysed using non-metric multidimensional scaling and permutational multivariate ANOVA; edaphic characteristics were incorporated to explain differences. Soil fungal communities were not differentially affected by excluding ungulates for three months. Areas with high deer densities had a richer saprotrophic community and where lowland environments were dominated by the main tree hosts Quercus faginea and Quercus ilex. Arbutus unedo was found in mountain areas where there was less herbivore pressure, a greater richness of ectomycorrhizal and lichenized fungi and soils positively associated to nitrogen, phosphorus, potassium and organic matter levels.
•High deer densities, have favoured a saprotrophic environment.•AM fungal communities were not altered by any of the studied variables.•The richness of ECM fungal communities was higher in areas with low deer pressure and in elevated areas.•The influence of pH was greater in stands with moderate or high deer pressure.•In stands with low to moderate deer pressure, fungal communities were influenced by N, P, K and organic matter.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Plant root exudates are considered as critical substrates mediating the interaction between rhizosphere microorganisms and plants. However, little is known about how microbial community response to ...root exudates under nitrogen (N) fertilization in agroecosystems. Here, we applied stable isotope probing to divide fungi in wheat rhizosphere soil (under 37-year N fertilization regimes) into two biological compartments: 13C-labeled and 12C-labeled fungal communities. High-throughput pyrosequencing was followed to characterize the two biological compartments. Long-term N fertilization changed rhizosphere soil physiochemical properties, and increased the quantity of plant root exudates. 13C-labeled fungi had lower diversity than 12C-labeled fungi. The fungal communities were predominantly composed of Ascomycota and Basidiomycota in both the 13C-labeled and 12C-labeled DNA, and the abundance of those two phyla were higher in 13C-labeled than that in 12C-labeled DNA. The Nonmetric Multidimensional Scaling (NMDS) showed that 13C-labeled and 12C-labeled fungal communities were distinct from each other. Long-term N fertilization altered fungal communities in 13C-labeled DNA, with lower abundance of putative fungal pathogens, and higher abundance of Glomeromycota. Although N fertilization significantly decreased 12C-labeled fungal diversity, no significant differences were detected in 13C-labeled fungal diversity, indicating the microbial species responses to root exudates and fertilization both influenced fungal diversity. In addition, 13C-labeled fungal communities were less determined by soil chemical properties than 12C-labeled fungal communities, based on partial Mantel test. Overall, our results revealed that long-term N fertilization, which increased the quantity of plant root exudates, altered 13C-labeled fungal community composition, but not changed 13C-labeled fungal diversity in our studied ecosystem.
•The rhizosphere fungi were characterised by stable isotope probing and pyrosequencing.•13C-labeled fungal communities were different from 12C-labeled fungal communities.•N-addition decreased the abundance of putative pathogens, but increased Glomeromycota.•Long-term fertilization did not significantly change 13C-labeled fungal diversity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Global climate change can affect the soil thermal and moisture condition, potentially disrupting microbial-mediated soil respiration and altering the soil C cycle. However, the complex relationship ...between the soil C turnover and transient thermal and moisture conditions is not fully understood. Specifically, quantitative understanding is lacking regarding the impact of drought-rewetting events and temperature on the response of soil organic carbon (SOC) decomposition rate to exogenous C input, known as the priming effects (PEs). Herein, we quantified glucose-induced PEs during the rewetting of soils incubated under two drought intensities with 20 % and 33 % water holding capacity (WHC), at different incubation temperatures (15, 25, and 35 °C). Moreover, the effect size of drought intensities on PEs and the temperature sensitivity of PEs were quantified using lnRR (Response Ratio) and Q10 of PEs. Glucose input triggered positive PEs after 21 d incubation and increased SOC decomposition by 29.7-72.7 %. Drought intensity showed positive effect (lnRR > 0) on PEs at lower temperatures (15 and 25 °C) but showed negative effect (lnRR < 0) on PEs at higher temperature (35 °C). At moderate drought intensity (33 % WHC) before rewetting, PEs increased significantly with incubation temperature (Q10 = 1.65). Contrastingly, at high drought intensity (20 % WHC), temperature did not significantly influence PEs during the 21-d incubation after rewetting (Q10 = 0.96). The combination of drought, temperature change and glucose addition significantly changed the abundances in the dominant bacterial phyla (Proteobacteria, Actinobacteria, and Chloroflexi) and fungal phylum (Ascomycota), which likely affect PEs. Furthermore, the decrease in the demand for microbial-driven N mining, which is a crucial factor in promoting positive PEs, was associated with drought intensity at high temperature (35 °C). Our study provided a quantitative and mechanistic understanding of the impact of drought intensity on PEs before rewetting and its temperature sensitivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rhizopus oryzae causes tobacco pole rot in China during tobacco flue-curing. Flue-curing is a post-harvest process done to prepare tobacco leaves and involves three different stages: the yellowing ...stage has the lowest temperatures and highest humidity, then the color-fixing stage has higher temperatures and medium humidity, and finally the stem-drying stage has the highest temperatures and lowest humidity. In this study, fungal culturing and IonS5XL high-throughput sequencing techniques were used to reveal the fungal community of the petioles and lamina of tobacco leaves infected with pole rot during flue-curing. A total of 108 fungal isolates belonging to 6 genera were isolated on media. The most common fungal species isolated was the pathogen, R. oryzae, that was most often found equally on petioles and laminas in the color-fixing stage, followed by saprotrophs, mostly Aspergillus spp. High-throughput sequencing revealed saprotrophs with Alternaria being the most abundant genus, followed by Phoma, Cercospora, and Aspergillus, whereas Rhizopus was the tenth most abundant genus, which was mostly found on petioles at the yellowing stage. Both culturable fungal diversity and fungal sequence diversity was higher at stem-drying stage than the yellowing and color-fixing stages, and diversity was higher with leaf lamina than petioles revealing that the changes in fungal composition and diversity during the curing process were similar with both methods. This study demonstrates that the curing process affects the leaf microbiome of tobacco during the curing process, and future work could examine if any of these saprotrophic fungi detected during the curing of tobacco leaves may be potential biocontrol agents for with pole rot in curing chambers.
Arbuscular mycorrhizal fungi (AMF) have a broad distribution and establish symbiotic relationships with vascular plants in tropical regions. They play a crucial role in enhancing plant nutrient ...absorption, mitigating pathogenic infections, and boosting the resilience of host plants to abiotic stresses, including drought under specific conditions. Many natural forests in Ethiopia are being replaced by monospecific plantations. However, the impact of these actions on AMF is unknown and, despite their ecological functions, AMF communities in various forest systems have not been thoroughly investigated. In this study, we assessed soil AMF communities in natural and plantation forests by DNA metabarcoding of the ITS2 rDNA region and assessed the influence of climate and environmental variables on the AMF community. In total, 193 AMF operational taxonomic units (OTUs), comprising nine families and 15 genera, were recorded. Glomerales was the dominant order (67.9 % of AMF OTUs) and Septoglomus fuscum, Diversispora insculpta, and Funneliformis mosseae were the dominant species. AMF were more abundant in natural forests than in plantation forests and the composition of AMF communities differed significantly from those of plantation forest. In plantation forests, soil pH, organic carbon, total nitrogen, and available phosphorus significantly influenced the composition of AMF communities, whereas in natural forest, electrical conductivity, annual rainfall, and cumulative rainfall before sample collection were significantly correlated with AMF. SIMPER analysis identified the AMF responsible for composition variances among different forest types, with the Glomeraceae family being the most significant contributor, accounting for nearly 60 % of the dissimilarity. Our findings further our understanding of the ecological niche function and the role of AMF in Ethiopia's natural forest systems and highlight the importance of prioritizing the sustainable development of degraded natural forests rather than plantations to ensure the preservation of habitats conducive to maintaining various AMF communities when devising conservation and management strategies.
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•Changes in forest types resulted in the divergence of AM fungi communities.•Soil pH, organic carbon, and annual rainfall, significantly influenced AMF diversity.•Septoglomus fuscum, Diversispora insculpta, and Funneliformis mosseae emerge as dominant AMF species.•Glomeraceae is found as a dominant contributor to AMF community.•Conserving native forests is promising to enhance diverse AMF communities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Wheat crop production needs nitrogen (N) for ensuring yield and quality. High doses of inorganic N fertilizer are applied to soil before sowing (basal dressing), with additional doses supplied along ...the cultivation (top dressing). Here, a long-term wheat field trial (12 plots), including four conditions (control, N top dressing,
Trichoderma harzianum
T34 seed-inoculation, and top dressing plus T34) in triplicate, was performed to assess, under high basal N fertilization, the influence of these treatments on crop yield and root microbial community shaping. Crop yield was not affected by top dressing and
T. harzianum
T34, but top dressing significantly increased grain protein and gluten contents. Twenty-seven-week old wheat plants were collected at 12 days after top dressing application and sampled as bulk soil, rhizosphere and root endosphere compartments in order to analyze their bacterial and fungal assemblies by 16S rDNA and ITS2 high-throughput sequencing, respectively. Significant differences for bacterial and fungal richness and diversity were detected among the three compartments with a microbial decline from bulk soil to root endosphere. The most abundant wheat root phyla were Proteobacteria and Actinobacteria for bacteria, and Ascomycota and Basidiomycota for fungi. An enrichment of genera commonly associated with soils subjected to chemical N fertilization was observed:
Kaistobacter
,
Mortierella
, and
Solicoccozyma
in bulk soil,
Olpidium
in rhizosphere, and
Janthinobacterium
and
Pedobacter
in root endosphere. Taxa whose abundance significantly differed among conditions within each compartment were identified. Results show that: (i) single or strain T34-combined application of N top dressing affected to a greater extent the bulk soil bacterial levels than the use of T34 alone; (ii) when N top dressing and T34 were applied in combination, the N fertilizer played a more decisive role in the bacterial microbiome than T34; (iii) many genera of plant beneficial bacteria, negatively affected by N top dressing, were increased by the application of T34 alone; (iv) bulk soil and rhizosphere fungal microbiomes were affected by any of the three treatments assayed; and (v) all treatments reduced
Claroideoglomus
in bulk soil but the single application of T34 raised the rhizosphere levels of this mycorrhizal fungus.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
8.
Dead wood diversity promotes fungal diversity Yang, Shanshan; Limpens, Juul; Sterck, Frank J. ...
Oikos,
December 2021, 2021-12-00, 20211201, Volume:
130, Issue:
12
Journal Article
Peer reviewed
Open access
Dead wood is a source of life as it provides habitat and substrate for a wide range of fungal species. A growing number of studies show an important role of wood quality for fungal diversity, but in ...most cases for a limited number of wood traits or tree species. In this study, we evaluate how abiotic and biotic factors affect the fungal diversity and composition during dead wood decomposition. For ten common European tree species, fresh similar‐sized logs were incubated simultaneously in two Dutch forests. Annual surveys of fungal fruiting bodies were made for an 8‐year period. For each tree species, 20 fresh stem traits were measured that are important for chemical and physical defence and for nutritional quality. Throughout eight years, 4644 fruiting bodies belonging to 255 species and 90 genera were recorded on the logs of ten tree species. Fungal frequency and richness were higher for Angiosperms than for Gymnosperms, both for individual tree species and as a group, and higher for tree species with more acquisitive stem trait strategies (i.e. high nutritional value and low physical defence). Differences in fungal communities were strongly driven by phylogenetic group (Gymnosperms versus Angiosperms), stem traits, decay time and forest sites, together explaining 23% of the variation. Fungal communities in sandy site diverged early in the decay process but converged later because of substrate homogenization. Of the 128 fungal species included in the analyses, 41% showed a preference for specific tree species and 34% for a specific successional year. In conclusion, dead wood quality, determined by tree species and decay stage, is an important driver of fungal diversity. For forest management, promoting a wide array of dead tree species (especially angiosperm species), a range of stem trait values and decay stages will increase fungal and, thereby, forest biodiversity.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Purpose
Elucidating the interactions of above- and below-ground communities in forest ecosystems is of great importance for comprehending biodiversity maintenance and ecosystem functioning.
Methods
...In the context of a Biodiversity and Ecosystem Functioning experiment conducted in China (BEF-China), we explored the combined effects of tree species richness (1, 2, and 4) and shrub species richness (0, 2, 4, and 8) on soil fungal community diversity and structure under tree species with different mycorrhizal types (i.e., arbuscular mycorrhizal (AM) tree and ectomycorrhizal (EM) tree) using the Illumina sequencing method.
Results
Results demonstrated that the fungal alpha diversity, community composition and network structure were significantly different between EM trees and AM trees. Although tree and shrub species richness had no significant interactive effect on soil fungal alpha diversity regardless of tree mycorrhizal types, however, their interactions did influence fungal community composition and co-occurrence network structure. Specifically, the interactive effect of tree and shrub species richness on soil fungal community composition was observed in AM trees, and their interactions affected the soil fungal co-occurrence network structure in EM trees.
Conclusions
These findings highlight the tree mycorrhizal type dependence of the interactive effects of tree and shrub species richness on soil fungal communities in a subtropical forest.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Afforestation has a substantial influence on soil fungal communities by introducing ecological variations within forest ecosystems via the inclusion of distinct tree species (coniferous and ...broadleaf) and afforestation patterns (pure forests and mixed forests). However, the specific effects of these variations on soil fungal communities require further investigation. Soil samples from birch (B:
Betula platyphylla
Suk.), larch (L:
Larix gmelinii
(Rupr.) Kuzen.), and mixed birch and larch (B–L) forests were used in this study, and a shrub–grassland field (S–G) was used as a reference. The abundance, diversity, and community composition of fungi in the soil of the monoculture forest (B and L), mixed forest (B–L), and S–G were studied by high‐throughput sequencing. The results showed that
Basidiomycota
was the dominant fungus in B and B–L, and the dominant genera were
Inocybe
and
Amanita
, respectively. Ascomycota was the dominant fungus in L and S–G, and the dominant genus was
Mortierella
. Afforestation reduced the richness and diversity of soil fungi. Larch forests were richer in soil fungi than B and B–L forests. Soil organic carbon was the main soil factor affecting the soil fungal community structure. Soil fungal community network changed less after planting L than after planting B and B–L, and the soil fungal community structure was more complex and stable in L than in B and B–L. For soil fungal community composition and function, mixed forests did not show outstanding advantages. Planting monoculture forests may be a more effective afforestation strategy in the rocky mountain areas of North China.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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