Relationships between Stand Composition and Ectomycorrhizal Community Structure in Boreal Mixed-Wood Forests

Abstract

We investigated the community structure of ectomycorrhizal fungi under varying overstory tree compositions in the southern mixed-wood boreal forest of Quebec. Sampling took place at two locations of differing postfire ages and nine 100-m2 plots were sampled per location. The dominant overstory tree species in the plots were trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.) or white spruce [Picea glauca (Moench) Voss], and balsam fir [Abies balsamea (L.) Mill.]. Mycorrhizae were analyzed using morphological as well as molecular methods, employing fungal-specific primers to amplify ribosomal DNA for subsequent cloning and sequencing. A total of 1800 mycorrhizal root tips collected from the 18 plots were morphologically classified into 26 morphotypes, with Cenococcum geophilum dominating (36% of root tips). A second set of root tips, selected from the same 18 samples on which the morphological analysis was based, were analyzed using molecular methods. From this analysis, 576 cloned polymerase chain reaction products were screened by restriction fragment length polymorphism analysis and a total of 207 unique types were found. No one type dominated the system and 159 occurred only once. Sequence analysis of the types that occurred more than once revealed that Piloderma sp., Russula sp., Cortinarius sp., and Lactarius sp. were the most common mycorrhizae. The ectomycorrhizal fungal community structure revealed by the rDNA analysis differed from that observed using morphological methods. Canonical correspondence analyses of the sequenced restriction types and % overstory composition indicate that the distributions of ectomycorrhizal fungi are influenced by the relative proportions of host tree species. The distinct fungal assemblages found in the different plots supported by the different combinations of host tree species provides further support for the need to conserve stand diversity in the southern boreal forest.

Concordance between vascular plant and macrofungal community composition in broadleaf deciduous forests in central Italy

“…Such result may be interpreted as due to the fact that herbaceous species are not functionally relevant to EMF species, therefore their inclusion in the analysis provides a lower variance accounted for in the data sets analyzed. The concordance between the woody species community with the EMF community found in this investigation agrees with previous studies demonstrating that the EMF community composition is mainly related to tree and shrub species (Kernaghan et al 2003, Cripps 2004, Lodge et al 2004, De Bellis et al 2006, Kirk et al 2008. A similar concordance was also found between the woody species and the Sh fungi communities, but only when both data sets were based on frequency.…”

“…Coprophilous saprotrophs were absent. The above approach was adopted because many macrofungi are related to woody plant species by their trophic requirements and trophic groups may be strongly shaped by forest composition and structure (e.g., mycorrhizal species and many saprotrophic fungi - Roberts et al 2004, De Bellis et al 2006, Santos-Silva et al 2011.…”

Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

“…For example, this could explain the absence of the genus Marasmiellus from fungal taxa identified by next-generation sequencing, since members of this genus are specialized decomposers of spruce needles, and they are probably present in the very top litter layer only. Though the results of our fruiting body inventory are suggestive, they reflect the outcomes of most of previous studies of fungal diversity in forests of the Northern Hemisphere (43)(44)(45). The fungal communities colonizing the wood showed pronounced differences compared to those of the surrounding soils.…”

Ectomycorrhizal fungal community associated with autochthonous white poplar from Serbia

“…It seems that the number of ECM fine roots and the diversity of ECM types in poplar are highly variable, and the naturalness of the studied Special Nature Reserve does not contribute to increase ECM diversity as compared with other poplars' sites. Values of Shannon-Weaver's diversity index (1.95 in spring and 2.00 in autumn) are in accordance with results obtained by DeBellis et al (2006). These authors recorded a similar Shannon-Weaver diversity index of 2.00 in an aspen-dominated plot by using morphological characterization of ECM types, but a considerably higher index was recorded (3.00) when molecular identification tools were applied.…”