Distribution Of Ectomycorrhizal Fungi Research Articles

Soil fungal communities of ectomycorrhizal dominated woodlands across West Africa.

Forests and woodlands in the West African Guineo-Sudanian transition zone contain many tree species that form symbiotic interactions with ectomycorrhizal (ECM) fungi. These fungi facilitate plant growth by increasing nutrient and water uptake and include many fruiting body-forming fungi, including some edible mushrooms. Despite their importance for ecosystem functioning and anthropogenic use, diversity and distribution of ECM fungi is severely under-documented in West Africa. We conducted a broad regional sampling across five West African countries using soil eDNA to characterize the ECM as well as the total soil fungal community in gallery forests and savanna woodlands dominated by ECM host tree species. We subsequently sequenced the entire ITS region and much of the LSU region to infer a phylogeny for all detected soil fungal species. Utilizing a long read sequencing approach allows for higher taxonomic resolution by using the full ITS region, while the highly conserved LSU gene allows for a more accurate higher-level assignment of species hypotheses, including species without ITS-based taxonomy assignments. We detect no overall difference in species richness between gallery forests and woodlands. However, additional gallery forest plots and more samples per plot would have been needed to firmly conclude this pattern. Based on both abundance and richness, species from the families Russulaceae and Inocybaceae dominate the ECM fungal soil communities across both vegetation types. The community structure of both total soil fungi and ECM fungi was significantly influenced by vegetation types and showed strong correlation within plots. However, we found no significant difference in fungal community structure between samples collected adjacent to different host tree species within each plot. We conclude that within plots, the fungal community is structured more by the overall ECM host plant community than by the species of the individual host tree that each sample was collected from.

Recovering lost ground: Effects of soil burn intensity on nutrients and ectomycorrhiza communities of ponderosa pine seedlings

Fuel accumulation and climate shifts are predicted to increase the frequency of high-severity fires in ponderosa pine (Pinus ponderosa) forests of central Oregon. The combustion of fuels containing large downed wood can result in intense soil heating, alteration of soil properties, and mortality of microbes. Previous studies show ectomycorrhizal fungi (EMF) improve ponderosa seedling establishment after fire but did not compare EMF communities at different levels of soil burn intensity in a field setting. For this study, soil burn intensity effects on nutrients and EMF communities were compared at Pringle Falls Experimental Forest, La Pine, Oregon. Twelve replicate sites were used, each with three treatments: high intensity soil burn from large downed wood combustion (HB), low intensity soil burn (LB), and unburned control (UB). Temperatures lethal to fungi were detected at 0-cm, 5-cm, and 10-cm depths in HB soils and 0-cm depth in LB soils. Ponderosa pine seedlings planted post-burn were harvested after four months for EMF root tip analysis. We found: (a) greater differences in soil properties and nutrients in HB soils compared to LB and UB soils; (b) no differences in EMF richness and diversity among treatments; (c) weak differences in community composition based on relative abundance between UB and either burn treatments; and (d) EMF composition in HB and LB treatments correlated with soil carbon and organic matter contents. These results support the hypothesis that the combustion of large downed wood can alter the soil environment directly beneath it. However, an EMF community similar to LB soils recolonized HB soils within one growing season. Community results from both burn treatments suggest an increase in patchy spatial distribution of EMF. We hypothesize that quick initiation of EMF recolonization is possible depending on the size of high intensity burn patches, proximity of low and unburned soil, and survival of nearby hosts. The importance of incorporating mixed fire effects in fuel management practices will help to provide EMF refugia for ponderosa pine forest regeneration.

Consequences for ectomycorrhizal fungi of the selective loss or gain of pine across landscapes

Altered disturbance regimes and novel introductions are causing rapid shifts in the distribution of pines (Pinus L.). The functionally obligate symbiosis between pines and ectomycorrhizal (EM) fungi dictates that shifts in the distribution of one partner will affect the distribution of the other. In this review, we examine evidence for three hypotheses. (1) The loss of photosynthates through stress or tree mortality decreases the abundance of EM fungi and selects for less carbon-demanding species. (2) Pine introductions initiate establishment of novel EM fungal communities. (3) The extent of shifts in EM fungal abundance and community composition is mediated by surrounding vegetation. We find support for these hypotheses though changes in EM fungal abundance are variable and context-dependent. We posit that the consequences of shifts in EM fungal abundance and community composition extend beyond the individual tree to the landscape; these changes may affect population dynamics of both symbionts, ecosystem processes, and the conservation and evolution of fungi. In addition to conducting baseline surveys to assess the distribution of EM fungi, increasing our understanding of their function, morphology, propagation, and controls on host-specificity, and shifts would also assist in predicting the trajectory of ecosystems following the loss or gain of pine.

Ectomycorrhizal fungal communities of Quercus liaotungensis along local slopes in the temperate oak forests on the Loess Plateau, China

AbstractTopographic factors strongly affect the diversity of plants and local environmental conditions, yet little is known about their effects on the distribution of ectomycorrhizal fungi (EMF). By combining morphological and molecular identification methods, we investigated the relationship between EMF communities of Quercus liaotungensis and topographic factors along local slopes in the temperate oak forest on the Loess Plateau of northwest China. ITS‐RFLP analysis revealed a high diversity of EMF taxa (135 taxa) associated with Q. liaotungensis along three local slopes. EMF communities among slope sites or slope positions, tended to share major common EMF species, which accounted for more than 80 % of the total EMF abundance, and showed a diverse distribution, which mainly related to rare species. Ordination analyses showed that EMF taxa distribution was significantly correlated with several environmental variables (slope site, slope position, slope gradient, and soil C:N). Topography‐mediated changes of environmental conditions may be important determinants of the distribution of EMF taxa along local slopes (slope position and slope site) in the central Loess Plateau.

Distribution of ectomycorrhizal fungi in a Chamaecyparis obtusa stand at different distances from a mature Quercus serrata tree

Ectomycorrhizal fungal distributions at different distances from one mature Quercus serrata tree were demonstrated in a Japanese cypress stand. After 4 months for field-planted and 3 months for laboratory-incubated Q. serrata seedlings, they were evaluated ectomycorrhiza formations. For the field-planted seedlings, molecular discrimination was conducted to clarify the species diversity of ectomycorrhizal fungi. Ectomycorrhiza formation was confirmed at all distances in both methods. However, the formation and associating fungal species were decreased with increasing distance. These results indicate that the density and diversity of ectomycorrhizal fungi decrease rapidly within several tens of meters from arbuscular mycorrhizal forest edges.

Distribution and drivers of ectomycorrhizal fungal communities across the North American Arctic

Ectomycorrhizal fungi (EMF) form symbioses with a few plant species that comprise a large fraction of the arctic vegetation. Despite their importance, the identity, abundance and distribution of EMF in the Arctic, as well as the key drivers controlling their community composition are poorly understood. In this study, we investigated the diversity and structure of EMF communities across a bioclimatic gradient spanning much of the North American Arctic. We collected roots from two principal arctic ectomycorrhizal host plants, Salix arctica and Dryas integrifolia, typically growing intermingled, at 23 locations stratified across the five bioclimatic subzones of the Arctic. DNA was extracted from ectomycorrhizal root tips and the ITS region was sequenced and phylogenetically analyzed. A total of 242 fungal Operational Taxonomic Units (OTUs) were documented, with 203 OTUs belonging to the Basidiomycota and 39 to the Ascomycota, exceeding the number of previously morphologically described EMF in the Arctic. EMF communities were dominated by a few common and species‐rich families such as Thelephoraceae, Inocybaceae, Sebacinaceae, Cortinariaceae, and Pyronemataceae. Both host plants showed similar species richness, with 176 OTUs on Salix arctica and 154 OTUs on Dryas integrifolia. Host plant identity did not affect EMF community composition. The ten most abundant OTUs had a wide geographic distribution throughout the Arctic, and were also found in boreal, temperate and Mediterranean regions, where they were associated with a variety of hosts. Species richness did not decline with increasing latitude. However, EMF community structure changed gradually across the bioclimatic gradient with the greatest similarity between neighboring bioclimatic subzones and locations. EMF community structure was correlated with environmental factors at a regional scale, corresponding to a complex of glaciation history, geology, soil properties, plant productivity and climate. This is the first large‐scale study of EMF communities across all five bioclimatic subzones of the North American Arctic, accompanied by an extensive set of environmental factors analyzed to date. While our study provides baseline data to assess shifts of plant and fungi distribution in response to climate change, it also suggests that with ongoing climate warming, EMF community composition may be affected by northward shifts of some taxa.

Distribution of ectomycorrhizal and pathogenic fungi in soil along a vegetational change from Japanese black pine (Pinus thunbergii) to black locust (Robinia pseudoacacia)

The nitrogen-fixing tree black locust (Robinia pseudoacacia L.) seems to affect ectomycorrhizal (ECM) colonization and disease severity of Japanese black pine (Pinus thunbergii Parl.) seedlings. We examined the effect of black locust on the distribution of ECM and pathogenic fungi in soil. DNA was extracted from soil at depths of 0-5 and 5-10 cm, collected from the border between a Japanese black pine- and a black locust-dominated forest, and the distribution of these fungi was investigated by denaturing gradient gel electrophoresis. The effect of soil nutrition and pH on fungal distribution was also examined. Tomentella sp. 1 and Tomentella sp. 2 were not detected from some subplots in the Japanese black pine-dominated forest. Ectomycorrhizas formed by Tomentella spp. were dominant in black locust-dominated subplots and very little in the Japanese black pine-dominated forest. Therefore, the distribution may be influenced by the distribution of inoculum potential, although we could not detect significant relationships between the distribution of Tomentella spp. on pine seedlings and in soils. The other ECM fungi were detected in soils in subplots where the ECM fungi was not detected on pine seedlings, and there was no significant correlation between the distribution of the ECM fungi on pine seedlings and in soils. Therefore, inoculum potential seemed to not always influence the ECM community on roots. The distribution of Lactarius quieticolor and Tomentella sp. 2 in soil at a depth of 0-5 cm positively correlated with soil phosphate (soil P) and that of Tomentella sp. 2 also positively correlated with soil nitrogen (soil N). These results suggest the possibility that the distribution of inoculum potential of the ECM fungi was affected by soil N and soil P. Although the mortality of the pine seedlings was higher in the black locust-dominated area than in the Japanese black pine-dominated area, a pathogenic fungus of pine seedlings, Cylindrocladium pacificum, was detected in soil at depths of 0-5 and 5-10 cm from both these areas. This indicates that the disease severity of pine seedlings in this study was influenced by environmental conditions rather than the distribution of inoculum potential.

Distribution of ectomycorrhizal fungi in periodically inundated plant communities on the Pilica River floodplain

Studies on ectomycorrhizal symbionts in plant communities were developed in the experimental floodplain located in the middle reach of the Pilica River valley near Sulejów (central Poland). This area is a natural floodplain where habitats are permanently or periodically flooded. Its vegetation is highly diversified and includes haygrowing meadows (Molinio-Arrhenateretea), rush communities (Phragmitetea, Caricetea), willow shrubs (Salicetea) and pine monoculture. Samples of trees' and bushes' roots were collected using a metal probe, sporocarps of ectomycorrhizal fungi (ECMF) were collected together. Researches indicate that wet soil conditions and periodic flooding have a significant influence on mycorrhiza presence. The vast majority of ectomycorrhizal fungi were present in trees growing in dry habitats – willow bushes and pine monoculture (Salix species, Betula pendula and Pinus sylvestris). The species composition were determined - in total noted c.a. 40 species of ectomycorrhizal fungi and 15 morphological types. The number and diversity of ectomycorrhizal (ECM) morphotypes increased significantly from flooded to dry habitats. Despite the fact that extremely humid and dry soil conditions make a negative impact on mycorrhiza, symbiotic parthnership enable floodplain plant communities to tolerate water level fluctuations, eliminate water stress and provide plants tissues with e.g. phosphorous.

식재지별 외생균근성 버섯의 다양성 및 발생 빈도 비교

2000년 6월부터 2001년 10월까지 식재지별로 외생균근성 버섯을 조사한 결과는 다음과 같았다. 조사기간 동안 총 3강 3아강 8목 22과 41속 72종 (2변종 포함)의 버섯이 조사되었다. 버섯은 주름버섯목에 9과 21속 48종, 민주름버섯목에 5과 11속 13종, 이형담자균강에 3과 3속 4종, 복균아강에 5과 6속 7종이었다. 외생균근성 버섯은 총 7과 11곡 30종 2,451개체가 조사되었다. 버섯 개체수는 색시졸각버섯(1,225) 긴골광대버섯아재비(179), 자주졸각버섯(130)의 순으로 조사되었다. 외생균근성 버섯 발생은 기후환경요인과 밀접한 관계가 있는 7월과 8월에 집중하였다. 외생균근성 버섯의 종수 및 개체수 분포는 조사구별로 큰 차이가 있었으며, 이는 각 조사구별 입지환경 및 기주 수종 구성 등의 차이 때문인 것으로 사료되었다. 색시졸각버섯은 참나무속에서만 발생하여 기주선택성이 매우 좁고, 긴골광대버섯아재비, 수원무당버섯, 땀버섯속은 침엽수 및 활엽수 모두에서 버섯이 발생되어 기주선택성이 넓은 것으로 나타났다. 외생균근성 버섯의 분포에 영향을 주는 환경은 토양환경 중 토양 pH, 유기물함량 및 전질소함량과 기후환경인 상대습도가 중요한 인자로 나타났다. This study was conducted to investigate the diversity and occurrence frequency of ectomycorrhizal fruit bodies by planting sites from June 2000 to October 2001. A total of 3 classes 3 subclasses 8 orders 22 families 41 genera and 72 species (including two varieties) including saprophytic and ectomycorrhizal fungi was investigated. The mushrooms are classified into 9 families 21 genera and 48 species in Agaricales, 5 families 11 genera and 13 species in Aphllophorales, 3 families 3 genera and 4 species in Heterobasidiomycetes and 5 families 6 genus and 7 species in Gasteromycetdae. A total of 7 families 11 genera 30 species (2,451 ea.) of ectomycorrhizal mushroom was investigated. The occurrence frequency of mushrooms was 1,225, 179 and 130 times for Laccaria vinaceoavellanea, Amanita longistriata and Laccaria amethystea, respectively. The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature, relative humidity and lots of rainfall from July to August. Diversity and distribution of ectomycorrhizal fungi by plots were very different because of variable local environments and different host plants in experimental plots. Laccaria vinaceoavellanea has showed very low host range of plant specificity because of mushroom occurrence in only Quercus sp. and Amanita longistriata, Russula bella and Inocybe sp. have showed wide host range of plant specificity because of mushroom occurrence in coniferous and broadleaved trees. The environment which has a favorable influence of mushroom occurrence was soil pH, organic matter and T/N ratio of soil enviromental and humidity of climatic environment.

Observation and Distribution of Ectomycorrhizal Fungi in Pinus Roots

Detailed structures of ectomycorrhizae formed in Pinus roots were observed with various microscopes: light, fluorescence, and scanning electron microscopes. The mantles and Hartig nets commonly found in the structure of ectomycorrhiza were newly observed according to developmental stage by various staining. The mycelia were observed to be composed of coiled types on the surface of epidermal root during early stage and fused to form mantles of smooth fungal layers, loosing mycelia with some viscous liquid secreted. The ectomycorrhizal hyphae in anatomical roots penetrated the cortical layer and formed obviously mantle and Hartig net. The round spots of ectomycorrhizal mycelia were observed morphological distribution from the cortical layer to vascular bundle of stele in the ectomycorrhizal roots of Pinus species and especially scattered at the area of meristem at the root tip as longitudinal sections. Those mycelia penetrated seemed to move into other roots by means of vascular bundle of ectomycorrhizal roots and newly form ectomycorrhizal roots of dichotomous branches.