Arbuscular mycorrhizal tree communities have greater soil fungal diversity and relative abundances of saprotrophs and pathogens compared to ectomycorrhizal tree communities

Appl Environ Microbiol. 2021 Oct 20:AEM0178221. doi: 10.1128/AEM.01782-21. Online ahead of print.ABSTRACTTrees associating with different mycorrhizas often differ in their effects on litter decomposition, nutrient cycling, soil organic matter (SOM) dynamics, and plant-soil interactions. For example, due to differences between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree leaf and root traits, ECM-associated soil has slower rates of C and N cycling and lower N availability compared to AM-associated soil. These observations suggest many groups of non-mycorrhizal fungi should be affected by the mycorrhizal associations of dominant trees through controls on nutrient availability. To test this overarching hypothesis, we explored the influence of predominant forest mycorrhizal type and mineral N availability on soil fungal communities using next-generation amplicon sequencing. Soils from four temperate hardwood forests in Southern Indiana, USA, were studied; three forests formed a natural gradient of mycorrhizal dominance (100% AM tree basal area - 100% ECM basal area), while the fourth forest contained a factorial experiment testing long-term N addition in both dominant mycorrhizal types. We found that overall fungal diversity, as well as the diversity and relative abundance of plant pathogenic and saprotrophic fungi, increased with greater AM tree dominance. Additionally, tree community mycorrhizal associations explained more variation in fungal community composition...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Source Type: research