Nutrient availability and invader density regulate the diversity–invasibility relationship mediated by soil microbes

This dataset accompanies a study examining how native plant diversity, nutrient availability, and invader density interact to influence the growth of the invasive plant Phytolacca americana via soil microbial mechanisms in a temperate forest ecosystem. The dataset includes (1) aboveground biomass data of P. americana grown in soils conditioned by varying native plant diversity levels (1, 3, or 6 species), under different nutrient conditions (fertilized vs. non-fertilized) and invader planting densities (1, 2, or 4 individuals); and (2) soil fungal community data derived from high-throughput sequencing, including taxonomic profiles (from phylum to genus) and functional classifications assigned using FUNGuild (e.g., saprotrophs, pathogens, symbionts). These data support analyses of how plant–soil feedbacks and soil microbial composition mediate invasion success, and are valuable for researchers in the fields of invasion ecology, soil microbiology, and plant–microbe interactions., , # Nutrient availability and invader density regulate the diversity–invasibility relationship mediated by soil microbes

Dataset DOI: [10.5061/dryad.1ns1rn95g](10.5061/dryad.1ns1rn95g)

## Description of the data and file structure

This dataset contains measurements of aboveground biomass of the invasive plant *Phytolacca americana* and fungal community composition from soil samples collected under varying diversity treatments. The experiment manipulated native plant diversity, nutrient availability, and invader density to examine their interactive effects on plant invasibility and soil microbial dynamics.

#### Methodological information

We collected plant samples manually, oven-dried them, and weighed the dry biomass using an electronic balance to obtain plant biomass data. We isolated the total genomic DNA from 250 mg of each homogenized soil sample using the EZNA® Soil DNA Kit (Omega Bio-tek, Norcross, GA, USA) and quantified DNA concentrations using a NanoDrop2000 spectrophotomete...,