Effects of plant community history, soil legacy and plant diversity on soil microbial communities

Abstract

Plants influence belowground microbial communities, which in turn drive nutrient cycling, plant productivity, and the maintenance of plant diversity. Over time, associations between plant communities and their belowground microbiota may strengthen and become more specific. However, we do not know whether plant diversity affects bulk soil microbial community composition and diversity, and whether this association strengthens as micro-evolutionary processes modify plant communities through time. To address this, we used plant communities and soil from an eight-year-old biodiversity experiment (the Jena Experiment; ″old″ plant communities and ″old″ soil), plant communities without such history (″new″ plants), and soil from which any soil legacy was removed by sterilization (″new″ soil) to set up a field biodiversity experiment in which we factorially crossed plant community age with soil legacy for 52 different plant species compositions. We grew these plant-soil communities for four years in experimental plots with plant species richness ranging from 1, 2, 4, 8 to 60 species. At the end of the experiment, we sequenced bacterial 16S rRNA and fungal ITS fragments to compare soil microbial communities under new vs. old plant communities in new vs. old soils. Soil microbial diversity was positively but weakly associated with plant diversity, with the strongest difference in microbial diversity between plant monocultures and any community of more than one plant species. Particular plant community compositions were associated with particular microbial community compositions. Soil legacy (old soil) increased soil bacterial richness and evenness more strongly than did plant community age. Plant community age (old plant communities) significantly affected the abundance of 10% of fungal OTUs. Some of the effects of soil legacy on bacterial and fungal diversity were indirect via changes in soil abiotic and biotic properties. Our findings suggest that as experimental ecosystems develop over time, plant communities associate with specific microbiomes and plant species associate with specific soil microbial species. With increasing knowledge about the taxonomic identities of the microbial OTUs, our dataset in the future may be used for function-based analyses of the detected associations. This may eventually help to identify microbiomes that improve plant health and consequently plant community productivity.

Plant diversity improves resistance of plant biomass and soil microbial communities to drought

“…The organic carbon stored in soils (~2,000 billion tonnes) also exceeds the vegetative carbon pool and is directly controlled by microbial activities (Hutchins et al, 2019). Although there are differences in their diversity and carbon pool, the important linkages between plants and soil microbes have been reported in prior studies (Eldridge et al, 2021; Fierer, 2017; Schmid et al, 2021; Wardle et al, 2004). For example, besides the direct effect by modifying microbial physiology and community composition (Singh et al, 2010), global climate change indirectly affects soil microbial communities and the processes that they regulate (e.g.…”

Gone and forgotten: facilitative effects of intercropping combinations did not carry over to affect barley performance in a follow-up crop rotation

“…Altered AMF colonization of barley roots may be due to changes in their community composition from intercropping phase. AMF communities have been shown to co-vary with their host plant community composition and diversity (Schmid et al 2020;Smilauer et al 2020). Therefore, it is very likely that soil harbored differential AMF communities from intercropping phase, which may have varied in the degree of root colonization potential.…”

Soil composition and plant genotype determine benzoxazinoid-mediated plant-soil feedbacks in cereals

“…For instance, Jacobea vulgaris, a plant species of the Asteraceae family, was still responsive in the third generation to a first conditioning phase despite the growth of a second conditioning phase by different plant species in these soils (Wubs and Bezemer 2018). Longer term effects were seen with microbiota legacies inherited through different plant community diversities growing for 11 (Schmid et al, 2019) or 8 years (Schmid et al, 2021). Because PSFs can persist over multiple generations, it is possible that BX feedbacks are effective later points in time, i.e.…”