DOI: 10.5061/dryad.wh70rxww6
title: Competition mode and soil nutrient status shape the role of soil microbes in the diversity–invasibility relationship

description: Understanding the relationship between plant diversity and invasibility is
 essential in invasion ecology. Species-rich communities are hypothesized
 to be more resistant to invasions than species-poor communities. However,
 while soil microorganisms play a crucial role in regulating this
 diversity–invasibility relationship, the effects of plant competition mode
 and soil nutrient status on their role remain unclear. To address this, we
 conducted a two-stage greenhouse experiment. Soils were first conditioned
 by growing nine native species separately in them for 1 year, then mixed
 in various configurations with soils conditioned using one, three, or six
 species, respectively. Next, we inoculated the mixed soil into sterilized
 substrate soil and planted the alien species Rhus typhina and native
 species Ailanthus altissima as test plants. We set up two competition
 modes (intraspecific and interspecific) and two nutrient levels
 (fertilization using slow-release fertilizer and non-fertilization). Under
 intraspecific competition, regardless of fertilization, the biomass of the
 alien species was higher in soil conditioned by six native species. By
 contrast, under interspecific competition, the biomass increased without
 fertilization but remained stable with fertilization in soil conditioned
 by six native species. Analysis of soil microbes suggests that pathogens
 and symbiotic fungi in diverse plant communities influenced R. typhina
 growth, which varied with competition mode and nutrient status. Our
 findings suggest that the soil microbiome is pivotal in mediating the
 diversity–invasibility relationship, and this influence varies according
 to competition mode and nutrient status.
description: At 8 weeks after the start of the test phase, all aboveground and
 belowground parts of the test plants were harvested and rinsed with water.
 Owing to the death of some seedlings during the growth period, 502
 <em>R. typhina</em> individuals (interspecific: 239,
 intraspecific: 263) and 259 <em>A. altissima</em> individuals
 were harvested. The collected plant tissue was placed in a 70 °C oven to
 dry for a week and was weighed. The biomass of two <em>R.
 typhina</em> plants was measured together under intraspecific
 competition, and the biomass of <em>R. typhina</em> and
 <em>A. altissima</em> was measured separately under
 interspecific competition. <strong>Soil sampling,
 DNA extraction, amplicon sequencing, and bioinformatics
 analysis</strong> The 27 mixed fresh soil
 samples, collected from various diversity treatments and subsequently
 stored in a refrigerator at −80 °C, were analyzed for soil fungal
 community composition. The total microbial community DNA was extracted
 according to the instructions of the E.Z.N.A. Soil DNA Kit (Omega Bio-tek,
 Norcross, GA). The quality of the extracted DNA was verified using 1%
 agarose gel electrophoresis, and DNA concentration and purity were
 measured using a NanoDrop 2000 device (Thermo Fisher Scientific, Waltham,
 MA). The fungal rRNA internal transcribed spacer (ITS) region was
 amplified using the primer set ITS1F (5′-CTTGGTCATTTAGAGGAAGTAA-3′) and
 ITS2R (5′-GCTGCGTTCTTCATCGATGC-3′). Sequencing was performed using a MiSeq
 PE300/NovaSeq PE250 platform (Illumina, San Diego, CA). The Illumina MiSeq
 platform has a higher throughput and lower error rate than other
 high-throughput sequencers (Loman et al., 2012; Frey et al.,
 2014). Fungal sequences were classified using the UNITE
 database (version 8.0) and using the USEARCH11-uparse algorithm for
 clustering. Operational taxonomic unit (OTU) sequence similarity was 0.97.
 Species classification was performed using the unite8.0/its fungi
 database, and classification confidence was 0.7. As fungal DNA extraction
 failed for one sample, we obtained 26 samples of ITS rDNA.
description: # Competition mode and soil nutrient status shape the role of soil
 microbes in the diversity–invasibility relationship
 [https://doi.org/10.5061/dryad.wh70rxww6](https://doi.org/10.5061/dryad.wh70rxww6) ## Description of the data and file structure Data usage bootstrap: See plant biomass data at: Li et al.\_ plant biomass See soil fungi community data at: Li et al.\_ Fungi See soil FUNGuild function prediction at: Li et al.\_ FUN Guid ### DATA-SPECIFIC INFORMATION FOR: Li et al.\_ plant biomass 1\. Number of variables: 6 2\. Number of cases/rows: 763 3\. Variable List: "species" refers to the classification of plants as either alien or native. "diversity" refers to the level of plant diversity. "soil mixture types" refers to the types of soil mixtures. "interspecific competition" and "intraspecific competition" refer to the modes of competition. "fertilization" and "non-fertilization" refer to the nutrient levels. "total biomass" refers to the total plant biomass (g) under a specific treatment. ### DATA-SPECIFIC INFORMATION FOR: Li et al.\_ Fungi 1\. Number of variables: 28 2\. Number of cases/rows: 2940 3\. Variable List: OTU: operational taxonomic unit sample1: Experimental soil sample naming sample2: Experimental soil sample naming sample4: Experimental soil sample naming sample5: Experimental soil sample naming sample6: Experimental soil sample naming sample7: Experimental soil sample naming sample8: Experimental soil sample naming sample9: Experimental soil sample naming sample10: Experimental soil sample naming sample11: Experimental soil sample naming sample12: Experimental soil sample naming sample13: Experimental soil sample naming sample14: Experimental soil sample naming sample15: Experimental soil sample naming sample16: Experimental soil sample naming sample17: Experimental soil sample naming sample18: Experimental soil sample naming sample19: Experimental soil sample naming sample20: Experimental soil sample naming sample21: Experimental soil sample naming sample22: Experimental soil sample naming sample23: Experimental soil sample naming sample24: Experimental soil sample naming sample25: Experimental soil sample naming sample26: Experimental soil sample naming sample27: Experimental soil sample naming taxonomy: Microbial classification level ### DATA-SPECIFIC INFORMATION FOR: Li et al.\_ FUN Guid 1\. Number of variables: 29 2\. Number of cases/rows: 2940 3\. Variable List: Functional type: sample1: Experimental soil sample naming sample2: Experimental soil sample naming sample4: Experimental soil sample naming sample5: Experimental soil sample naming sample6: Experimental soil sample naming sample7: Experimental soil sample naming sample8: Experimental soil sample naming sample9: Experimental soil sample naming sample10: Experimental soil sample naming sample11: Experimental soil sample naming sample12: Experimental soil sample naming sample13: Experimental soil sample naming sample14: Experimental soil sample naming sample15: Experimental soil sample naming sample16: Experimental soil sample naming sample17: Experimental soil sample naming sample18: Experimental soil sample naming sample19: Experimental soil sample naming sample20: Experimental soil sample naming sample21: Experimental soil sample naming sample22: Experimental soil sample naming sample23: Experimental soil sample naming sample24: Experimental soil sample naming sample25: Experimental soil sample naming sample26: Experimental soil sample naming sample27: Experimental soil sample naming