Unraveling spatiotemporal variability of arbuscular mycorrhizal fungi in a temperate grassland plot

Abstract

Summary Soils provide a heterogeneous environment varying in space and time; consequently, the biodiversity of soil microorganisms also differs spatially and temporally. For soil microbes tightly associated with plant roots, such as arbuscular mycorrhizal fungi (AMF), the diversity of plant partners and seasonal variability in trophic exchanges between the symbionts introduce additional heterogeneity. To clarify the impact of such heterogeneity, we investigated spatiotemporal variation in AMF diversity on a plot scale (10 × 10 m) in a grassland managed at low intensity in southwest Germany. AMF diversity was determined using 18S rDNA pyrosequencing analysis of 360 soil samples taken at six time points within a year. We observed high AMF alpha‐ and beta‐diversity across the plot and at all investigated time points. Relationships were detected between spatiotemporal variation in AMF OTU richness and plant species richness, root biomass, minimal changes in soil texture and pH. The plot was characterized by high AMF turnover rates with a positive spatiotemporal relationship for AMF beta‐diversity. However, environmental variables explained only ≈20% of the variation in AMF communities. This indicates that the observed spatiotemporal richness and community variability of AMF was largely independent of the abiotic environment, but related to plant properties and the cooccurring microbiome.

Dispersal limitation relative to environmental filtering governs the vertical small‐scale assembly of soil microbiomes during restoration

“…In addition, a rather small proportion ( ca . 20%) of explained variation in arbuscular mycorrhizal fungi communities was observed within temperate grassland soils at a small scale (Goldmann et al, ). Future studies ought to take into more environmental variables, such as soil temperature and trace elements.…”

Stochastic Dispersal Rather Than Deterministic Selection Explains the Spatio-Temporal Distribution of Soil Bacteria in a Temperate Grassland

“…Previous analyses showed that this grassland plot features considerable spatio-temporal variability in plant productivity and diversity (Klaus et al, 2016), complex dependencies between general habitat properties and microbial parameters such as phospholipid fatty acid (PLFA) profiles and enzymatic activities (Regan et al, 2014(Regan et al, , 2017, as well as between ammonia-and nitrite-oxidizing microorganisms (Stempfhuber et al, 2015). High turnover of arbuscular mycorrhizal fungi, likely driven by stochastic processes (Goldmann et al, 2019), and taxon-dependent influences of edaphic variables on protists (Fiore-Donno et al, 2019) were previously described as well.…”

Early Stage Root-Associated Fungi Show a High Temporal Turnover, but Are Independent of Beech Progeny

“…Moreover, it was previously shown that both the plant species identity and intraspecific plant diversity can affect the associated microbiomes [3][4][5]. Besides seasonal differences in microbial diversity and activity in soils [6][7][8], the plant-development stage led to variability in associated microbiomes [9]. Schematic overview of the experimental design: (a) In October 2011 beech nuts were collected from four forest plots within the three sites of the Biodiversity Exploratories, i.e., Schwäbische Alb, Hainich-Dün, and Schorfheide-Chorin; (b) beech seedling grew in a greenhouse at Göttingen University; (c) in October 2012 beech seedling of different progenies were out-planted to nine forest plots per site; (d) in September 2014 and November 2017 beech trees on five Schorfheide-Chorin plots were sampled; (e) we collected roots and the attached rhizosphere soil and gained a total of 60 samples (three progenies × five plots × two sampling years × two compartments) for subsequent analyses of the beech rootassociated fungal mycobiome.…”