AUTHOR=Tedersoo Leho , Anslan Sten , Bahram Mohammad , Drenkhan Rein , Pritsch Karin , Buegger Franz , Padari Allar , Hagh-Doust Niloufar , Mikryukov Vladimir , Gohar Daniyal , Amiri Rasekh , Hiiesalu Indrek , Lutter Reimo , Rosenvald Raul , Rähn Elisabeth , Adamson Kalev , Drenkhan Tiia , Tullus Hardi , Jürimaa Katrin , Sibul Ivar , Otsing Eveli , Põlme Sergei , Metslaid Marek , Loit Kaire , Agan Ahto , Puusepp Rasmus , Varik Inge , Kõljalg Urmas , Abarenkov Kessy TITLE=Regional-Scale In-Depth Analysis of Soil Fungal Diversity Reveals Strong pH and Plant Species Effects in Northern Europe JOURNAL=Frontiers in Microbiology VOLUME=11 YEAR=2020 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01953 DOI=10.3389/fmicb.2020.01953 ISSN=1664-302X ABSTRACT=

Soil microbiome has a pivotal role in ecosystem functioning, yet little is known about its build-up from local to regional scales. In a multi-year regional-scale survey involving 1251 plots and long-read third-generation sequencing, we found that soil pH has the strongest effect on the diversity of fungi and its multiple taxonomic and functional groups. The pH effects were typically unimodal, usually both direct and indirect through tree species, soil nutrients or mold abundance. Individual tree species, particularly Pinus sylvestris, Picea abies, and Populus x wettsteinii, and overall ectomycorrhizal plant proportion had relatively stronger effects on the diversity of biotrophic fungi than saprotrophic fungi. We found strong temporal sampling and investigator biases for the abundance of molds, but generally all spatial, temporal and microclimatic effects were weak. Richness of fungi and several functional groups was highest in woodlands and around ruins of buildings but lowest in bogs, with marked group-specific trends. In contrast to our expectations, diversity of soil fungi tended to be higher in forest island habitats potentially due to the edge effect, but fungal richness declined with island distance and in response to forest fragmentation. Virgin forests supported somewhat higher fungal diversity than old non-pristine forests, but there were no differences in richness between natural and anthropogenic habitats such as parks and coppiced gardens. Diversity of most fungal groups suffered from management of seminatural woodlands and parks and thinning of forests, but especially for forests the results depended on fungal group and time since partial harvesting. We conclude that the positive effects of tree diversity on overall fungal richness represent a combined niche effect of soil properties and intimate associations.