Changes in fungal communities along a boreal forest soil fertility gradient

Abstract

Summary Boreal forests harbour diverse fungal communities with decisive roles in decomposition and plant nutrition. Although changes in boreal plant communities along gradients in soil acidity and nitrogen (N) availability are well described, less is known about how fungal taxonomic and functional groups respond to soil fertility factors. We analysed fungal communities in humus and litter from 25 Swedish old‐growth forests, ranging from N‐rich Picea abies stands to acidic and N‐poor Pinus sylvestris stands. 454‐pyrosequencing of ITS2 amplicons was used to analyse community composition, and biomass was estimated by ergosterol analysis. Fungal community composition was significantly related to soil fertility at the levels of species, genera/orders and functional groups. Ascomycetes dominated in less fertile forests, whereas basidiomycetes increased in abundance in more fertile forests, both in litter and humus. The relative abundance of mycorrhizal fungi in the humus layer remained high even in the most fertile soils. Tolerance to acidity and nitrogen deficiency seems to be of greater importance than plant carbon (C) allocation patterns in determining responses of fungal communities to soil fertility, in old‐growth boreal forests.

Plant functional diversity enhances associations of soil fungal diversity with vegetation and soil in the restoration of semiarid sandy grassland

“…2015; Sterkenburg et al. 2015). Effects of plant richness and CWM plant height on soil fungal richness were direct rather than indirect, while soil properties, function dispersion, and plant biomass acted indirectly.…”

“…2015; Sterkenburg et al. 2015). The trait‐based approach can clearly reveal effects of plant functional diversity on ecosystem function and properties (Petchey and Gaston 2006; Lienin and Kleyer 2012; Lavorel 2013).…”

Dimensions of biodiversity in the Earth mycobiome

“…Given the relatively large size of fungal individuals, environmental samples may sometimes be too small to adequately represent the community or environment that a species inhabits. As a result, species composition may seem to be highly unpredictable with respect to environmental conditions that are measured at the centimetre scale, but stable and predictable when samples are pooled at the scale of forest stands or tree canopies 73 .…”

“…For example, compared with bacteria, fungi are more able to tolerate acidic conditions and are less sensitive to changes in pH 100 . Indeed, for bacteria, pH seems to be the single most important driver of community structure in soils at large spatial scales 104 , whereas fungi are typically more sensitive to regional climate or other variables 4 , although pH can nevertheless constrain both fungal diversity and community structure 47,73 . Similarly, although marked evolutionary divisions seem to exist between communities of marine and terrestrial bacteria 105 , marine fungal communities that have been surveyed thus far are not as evolutionarily distinct from their terrestrial counterparts, with many of the dominant marine fungi seeming to be derived from terrestrial lineages of Ascomycota and Basidiomycota 23 (see above) or to occur in both marine and terrestrial environments.…”

“…Typically, species are grouped into saprotrophs, mutualists and pathogens, and then each of these trophic groups is divided into functional guilds of species that have different growth strategies and nutrient-acquisition capabilities 73 (FIG. 1).…”