164. Rincon, A. and Jose J. Pueyo. Effect of fire severity and site slope on diversity and structure of the ectomycorrhizal fungal community associated with post-fire regenerated Pinus pinaster Ait. seedlings. Forest Ecology and Management 260: 361-369. Effects Table: Fire Effects: Wildfire, General Fire Effects
Effects: EM species diversity and abundance
Investigated the diversity and structure of the ectomycorrhizal (EM) fungal community associated with post-fire regenerated Pinuspinaster and the influence of fire severity and site slope on EM assemblage patterns.
A total of 45 EM types were identified, and richness and diversity significantly increased from the first to the second autumn after fire.
Contrary to what was hypothesized, a high potential of active EM inoculum in soil immediately after fire was observed in their study. Basidiomycetes were predominant over Ascomycetes, and ruderal fungi, such as Rhizopogon, and generalist ones, such as Tomentella or Wilcoxinia were among the most representative fungal genera in all samplings.
Neither fire severity nor slope had a significant effect on fungal-richness and diversity. Overall EM community composition was similar in all samplings, although fire severity, site slope and elapsed time after fire caused evident shifts in presence or in relative frequencies of a number of EM types.
No significant effect of fire severity or slope on EM assemblage patterns was detected in the first two sampling after fire. However, a significant effect of fire severity was observed at the end of the second growing season.
The harvest of burned wood did not significantly affect EM fungal assemblages in the short term, although the slope did, probably due to the increased risk of erosion.
Authors conclude that fire severity and slope did not change the richness and diversity of EM fungi, but affected the composition and assemblage patterns of EM fungal community, triggering replacements and changes in frequency of some EM fungal species.
165. Cairney, J.W. and B. A. Bastias. Influences of fire on forest soil fungal communities. Canadian Journal of Forest Resources 37: 207-215. Effects Table: Fire: General Fire Effects
Effects: EM Species Diversity and Abundance
Effects of fire on soil-dwelling fungi are poorly understood. The authors review the disparate literature relating to fire effects on soil fungi, with emphasis on forest environments.
A variety of effects have been reported, including altered fungal community structure along with increased or decreased mycorrhizal colonization of roots. Such effects, along with their duration, appear to be site- and (or) fire-specific, but are likely to be greater in the upper soil horizons.
From what is known, it is considered that the frequency, intensity, and season of burning, along with other factors such as prevailing weather, soil moisture, and fuel load, determine the extent of fire disturbance of forest soil environments.
Where repeated burning occurs, the effects on soil fungal communities appear to be more pronounced with more frequent burning.
Although fire may effect structural changes in soil fungal communities, the functional significance of such changes as the ecosystem level remains difficult to assess.
The occurrence of “postfire” ascomycetes in forest and other habitats is well documented. These taxa, largely Pezizales, typically begin fruiting some 6 weeks or so after fire and persist in a successional manner for up to 2 years.
Table 1 in this publication lists published investigations of the effects of single burning events on soil fungi.
166. Gordon, M. and C. Apple. 2011. Field monitoring the seasonal variation in Albatrellusellisii mycelium abundance with a species-specific genetic marker. Mycologia 103(5): 950-958. Effects Table: Ecological: Ecology
Effects: Mycelial network
The conservation of rare fungal sites occurring on actively managed forest lands requires efficient site monitoring methods. In this study, species-specific primers for the putatively mycorrhizal Albatrellus ellisii (Russulales) were developed so that DNA extracted from soil samples at known sites of this fungus could be tested for the presence of A. ellisii mycelium with PCR.
This method was used to measure seasonal changes in the levels of A. ellisii mycelium at three study sites while the utility of this monitoring method was assessed.
They found that A. ellisii maintained a constant level of soil occupancy over three seasons, except at one site where mycelium abundance increased in the fall. No reduction in abundance was seen in the summer, although all three sites experienced significant summer drought.
The authors found species-specific genetic marker detection to be an effective and practical method for monitoring mycelial distribution of a target fungus in the soil.
The ability to obtain this data from rare fungal sites advances our capability to conserve these fungi, particularly within the managed forest landscape.
167. Bingham, M.A. and S.W. Simard. 2012. Mycorrhizal networks affect ectomycorrhizal fungal community similarity between conspecific trees and seedlings. Mycorrhiza (2012) 22: 317-326. Effects Table: Climate Change; Ecological: Ecology
Ectomycorrhizal (EM) networks (MN) are thought to be an important mode of EM fungal colonization of coniferous seedlings.
Authors examined EM fungal community similarity between mature trees and conspecific interior Douglas-fir (Pseudotsugamenziesii var. glauca) seedlings in two experiments where seed and nursery-grown seedlings originating from different locations were planted at various distances from trees along a climatic gradient.
At harvest, trees shared 60% of their fungal taxa in common with outplanted seedlings and 77% with germinants, indicating potential for seedlings to join the network of residual trees.
In both experiments, community similarity between trees and seedlings increased with drought.
However, community similarity was lower among nursery seedlings growing at 2.5 m from trees when they were able to form an MN, suggesting MNs reduced seedling EM fungal richness. For field germinants, MNs resulted in lower community similarity in the driest climates.
Conclude that MNs of trees influence EM colonization patterns of seedlings, and the strength of these effects increases with climatic drought.
168. Kipfer, T., B. Moser, S. Egli, T. Wohlgemuth, and J. Ghazoul. 2011. Ectomycorrhiza succession patterns in Pinus sylvestris forests after stand-replacing fire in the Central Alps. Oecologia (2011) 167: 219-228. Effects Table: Fire: General Fire Effects
Effects: Host species to sustain EM; EM species diversity and abundance
Investigated the resistance and resilience of EM fungal communities on a chronosequence of 12 Pinus sylvestris stands in Valais (Switzerland) and Val d’Aosta (Italy) affected by fire between 1990 and 2006.
Given that the presence of EcM fungi is necessary for the establishment of obligately ectomycorrhizal P. sylvestris, successful post-fire pine recruitment requires either a fire-resistant EcM community or one that is resilient through rapid re-colonization, or a combination of both.
Soil samples from burnt and non-burnt forests were analyzed with respect to Ectomycorrhizal (EcM) fungi by means of a bioassay.
The number of EcM species was significantly lower in samples from recently (2-5 years) burnt sites than non-burnt forest, and increased with time since fire reaching levels of adjacent forests after 15-18 years.
Community composition changed after fire but did not converge to that of non-burnt sites over the 18 year period.
Only Rhizopogon roseolus and Cenococcum geophilum were abundant in both burnt sites and adjacent forest.
Their data indicate fire resistance of some EcM fungal species as well as rapid resilience in terms of species number, but not in species composition.
As long as the function of different EcM species for seedling establishment is unknown, the consequences of long-term shifts in EcM community composition for tree recruitment remain unclear.
169. Cairney, J.W. 2011. Ectomycorrhizal fungi: the symbiotic route to the root for phosphorus in forest soils. Plant Soil (2011) 344: 51-71. Effects Table: Climate change
Effects: Nutrient source, Changes in soil chemistry, Nutrient cycling
Many forest trees have evolved mutualistic symbioses with ectomycorrhizal ECM) fungi that contribute to their phosphorus (P) nutrition.
Forest productivity is frequently limited by P, a phenomenon that is likely to become more widespread under future conditions of elevated atmospheric CO2 concentration.
Author reviews literature on processes (absorption, translocation and transfer to the plant host) in ECM fungus-mediated P nutrition of forest trees.
Evidence to date suggests that ECM fungi may make considerable contributions to meeting the likely increased P demand of trees under elevated CO2 via increased colonization levels, shifts in ECM fungal community structure and changed patterns of EMM production.
170. Mohatt, K. R., C.L. Cripps, and M. Lavin. 2008. Ectomycorrhizal fungi of whitebark pine (a tree in peril) revealed by sporocarps and molecular analysis of mycorrhizae from treeline forests in the Greater Yellowstone Ecosystem. Botany (2008) 86: 14-25. Effects Table: Ecological: Whitebark pine
Effects: EM Species Diversity and Abundance
Whitebark pine has declined 40%-90% throughout its range owing to blister rust infection, mountain pine beetle, fire suppression, and global climate change.
This study addresses the urgent need to discover the ectomycorrhizal (ECM) fungi critical to this tree species before forests are further reduced.
If certain mycorrhizal fungi are unique to whitebark pine, pines in general, or stone pines, these species are likely to decline along with the tree species. In addition, the isolated nature of forests at treeline and the unusual survival strategies of stone pines could have implications for the distribution of its fungal associates.
A study of mature whitebark pine forests across five mountain ranges in the Northern GYE confirmed 32 ECM species of fungi with the pine by sporocarp occurrence in pure stands or by identification of mycorrhizae with ITS-matching.
Boletales and Cortinariales (Cortinarius) comprise 50% of the species diversity discovered.
In Boletales, Suillus subalpinus (with stone pines), Suillus sibericus (stone pines), Rhizopogon evadens (five-needle pines), Rhizopogon sp. (pines) and a semi-secotioid Chroogomphus sp. (pines) are restricted to the hosts listed and are not likely to occur with other high elevation conifers in the GYE.
The ascomycete generalist, Cenococcum geophilum, was the most frequent (64%) and abundant (51%) ECM fungus on seedling roots, as previously reported for high elevation spruce-fir and lower elevation lodgepole pine forests in the GYE.
The relative importance of the basiodiomycete specialists and the ascomycete generalist to whitebark pine (and for seedling establishment) is not known, however this study is the first step in delineating the ECM fungi associated with this pine in peril.
Information on native ECM fungi associated with whitebark pine is also of value to the extensive efforts currently underway to restore whitebark pine forests using a combination of management strategies such as fire, logging, and the planting of rust-resistant nursery grown seedlings.
171. Massicotte, H.B., R. Molina, D.L. Luoma, and J.E. Smith. 1994. Biology of the ectomycorrhizal genus, Rhizopogon. II. Patterns of host-fungus specificity following spore inoculation of diverse hosts grown in monoculture and dual culture. New Phytol. 126: 677-690. Effects Table: Ecological: Ecology
Effects: Host Species to Sustain EM
Objectives were to: 1) assess host-fungus specificity and compare it to the results of previous pure culture syntheses with Rhizopogon; 2) broaden the scope of Pinaceae tested to include Picea and Abies (both are widespread forest trees that often associate with Pseudotsuga, Pinus and Tsuga); 3) determine the influence of primary hosts on development on neighboring host plants; and 4) evaluate the potential for interplant linkages via compatible mycorrhizal fungi.
Seedlings of Abies grandis, Alnus rubra, Pinus ponderosa, Picea sitchensis, Pseudotsuga menziesii and Tsuga heterophylla were grown in monoculture and dual culture in the greenhouse and inoculated with spore slurries of 20 isolates representing 15 species of ectomycorrhizal hypogeous fungi (11 Rhizopogon species, Alpova diplophloeus, Truncocolumella citrine, Melanogaster euryspermus and Zeeleromyces gilkeyae).
None of the fungal species had broad host range affinities.
A variety of specificity responses were exhibited by the different fungal taxa, ranging from genus-restricted to intermediate host range.
In monoculture, nine species of Rhizopogon formed ectomycorrhizas on Pinusponderosa whereas three Rhizopogon species formed ectomycorrhizas on Pseudotsuga menziesii. (See paper for list of species).
See paper for which species developed secondary hosts in dual culture.
172. Kubartova, E.O., A. Dahlberg, and J. Stenlid. 2012. Patterns of fungal communities among and within decaying logs, revealed by 454 sequencing. Molecular Ecology (2012) 21: 4514-4532. Effects Table: Ecological: Ecology
Effects: EM Species Diversity and Abundance; Coarse or Large Woody Material/Debris
They investigated fungal communities in decaying Norway spruce logs at various spatial scales at two environmentally different locations in Sweden.
On the basis of 454 pyrosequencing of the ITS2 region of rDNA, 1914 operational taxonomic units (OTUs) were detected in 353 samples.
The communities differed significantly among logs, but the physical distance between logs was not found to have a significant effect on whether fungal communities had any resemblance to each other.
Within a log, samples that were closer together generally had communities that showed more resemblance to each other than those that were further apart.
Only a few OTUs were detected in the majority of logs, whereas numerous OTUs were rare and present in only one or a few logs.
Wood-decaying Basidiomycetes were often represented by higher sequence reads in individual logs than Ascomycete OTUs, suggesting that Basidiomycete mycelia spread out more rapidly when established.
OTU richness tended to increase with the decay stage of the sample; however, the known wood decayers were most abundant in less-decomposed samples.
The fungi identified in the logs represented different ecological strategies.
Their findings differ from previously published sporocarp studies, indicating that the highly abundant fruiting species may respond to environment in different ways than the rest of the fungal community.
173. Lilleskov, E.A., T.J. Fahey, and G.M. Lovett. 2001. Ectomycorrhizal fungal aboveground community change over an atmospheric nitrogen deposition gradient. Ecological Applications (2001) 11(2): 397-410. Effects Table: Pollution; Atmospheric Changes
Effects: EM Species Diversity and Abundance
Atmospheric nitrogen deposition has been hypothesized as one of the causal factors in the decline of ectomycorrhizal fungal (EMF) sporocarps.
They assessed the effects of N deposition on EMF of forests dominated by white spruce (Picea glauca [Moench] Voss) over a short, steep N deposition gradient in Alaska. The study area had received high NH3 inputs from an industrial ammonia production facility for almost 30 years. Current N inputs varied 20-fold over the gradient.
High N inputs have increased soil N availability, which has led to decreased soil pH and base cation availability; increased foliar N and decreased foliar P, Mg, and K; increased tree growth; and replacement of mosses by grasses.
At the six lowest N sites, 144 species were encountered, whereas only 14 species were encountered at the six highest N sites.
With increasing mineral N availability in the organic horizon, there were declines in both total species richness (1994 and 1995) and total sporocarp abundance (1994 only).
Correlation analysis identified two groups of taxa that responded differently to the N inputs. One group (“nitrophobic” taxa: Cortinarius, Russula, Tricholoma, Lactarius, Hebeloma) declined in species richness or abundance with increasing organic horizon mineral N. In the second group (“nitrophilic” taxa: Lactarius, theiogalus, Laccaria, Pacillus involutus, and Hygrophorus olivaceoalbus), sporocarp abundance was either not correlated or slightly positively correlated with organic horizon N availability.
These results support the hypothesis that long-term N inputs alone may lead to loss of EMF sporocarp diversity and indicate that EMF should be considered in the establishment of critical loads of N.
174. Fischer, A.L., J-M Moncalvo, J.N. Klironomos, and J.R. Malcolm. 2012. Fruiting body and molecular rDNA sampling of fungi in woody debris from logged and unlogged boreal forests in northeastern Ontario. Ecoscience (2012) 19(4): 374-390. Effects Table: Timber Harvest: Clearcutting
Effects: EM Species Diversity and Abundance; Coarse or Large Wood Material/Debris
They used fruiting body and molecular sampling of the nrLSU gene to compare the composition and richness of fungal communities between 2 decay classes of conifer logs (classes 1 and 4) and among boreal mixed wood sites from 3 management histories (mechanized clearcutting, horse-based clearcutting, and unlogged).
Molecular sampling, based on selection of 20 clones per log, yielded 304 operational taxonomic units (OTUs); 97 from decay class 1 logs, 184 from decay class 4 logs, and 23 from both.
Community composition differed strongly between the 2 decay classes both for the fruiting body and OUT samples, with more species being recovered from decay class 4 than decay class 1 logs.
Community composition also significantly varied according to log diameter and volume for fruiting bodes.
The number of fruiting bodies on decay class 1 logs was significantly greater in unlogged than logged sites and also was positively correlated with site-level volume of recently-decayed conifer woody debris.
In this study, log characteristics, particularly decay class, importantly influenced fungal communities.
Despite relative large volumes of woody debris in the logged stands that we sampled, we obtained evidence that logging in these forests resulted some 30-60 years later in a reduction in the amount and diameter of early-decay coniferous downed wood, with reductions in fungal fruiting body diversity as a result.
In order to conserve biodiversity, it is evident that logging in boreal forests must consider the implications of harvesting for long-term dead wood supply.
