Litter nutrient release and allelopathy jointly contribute to the diversity–invasibility relationship

This dataset accompanies a study testing Elton’s biotic resistance hypothesis by examining how native plant litter diversity influences the growth of the invasive plant Phytolacca americana through nutrient release and allelopathic effects in temperate forests of China. The dataset includes: (1) Aboveground biomass data of P. americana grown in pots with litter mixtures composed of 15 native plant species at five species-richness levels (1, 3, 6, 9, 15); (2) Initial chemical properties (C and N concentrations, C:N ratios, and total phenolics) of the 15 native plant litter types; (3) Mass, C concentration, and N concentration of 61 litter mixtures measured before and after 10 weeks of decomposition to calculate litter C and N release; (4) 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); (5) Aboveground biomass data of P. americana from a litter-leachate experiment testing how leachates derived from litter mixtures of varying species richness affected the invader’s growth. These datasets support analyses of how litter species richness regulates nutrient dynamics, allelopathic effects, and invader performance, and are valuable for researchers studying invasion ecology, plant–soil interactions, and the role of biodiversity in ecosystem functioning.