Data from: Soil microorganisms weaken the positive legacy effect of nutrient fluctuation on growth of invasive plants

The fluctuating resource hypothesis posits that invasive species can capitalize on resource fluctuations, leading to their successful establishment. However, it remains unclear how nutrient fluctuations in native plant communities prior to invasion may indirectly affect the subsequent growth of invasive plants through changes in soil biogeochemical properties. This study investigated the effects of nutrient fluctuations on soil nutrient content, fungal diversity, and the subsequent growth of invasive plants in soils conditioned by native plant communities. We conducted a two-phase experiment involving five native plant communities and four invasive plant species. In the soil-conditioning phase, native communities were subjected to three nutrient treatments: constant low, constant high, and pulsed high. Soil samples were analyzed for native plant biomass, total nitrogen and phosphorus content, and fungal diversity. In the feedback phase, invasive plants were grown in sterilized and live soil from each treatment, and their biomass production and allocation were measured. During the conditioning phase, the constant high nutrient treatment increased the aboveground biomass of native communities, soil nitrogen content, and diversity of arbomycorhizzal fungi (AM) compared to the constant low treatment, but decreased soil phosphorus content and the diversity of pathogenic fungi. Furthermore, the pulsed high nutrient treatment increased the aboveground biomass of native communities, soil phosphorus content and the diversity of pathogenic fungi compared to the constant high treatment, but decreased soil N. In the second phase, invasive plants exhibited higher biomass production under soils conditioned by the constant high nutrient treatment than the constant low nutrient treatment, and the pulsed high nutrient treatment compared to the constant high nutrient treatment. The growth-promoting effect of the legacy from the pulsed high nutrient supply was more pronounced in sterilized soil compared to live soil, indicating that soil biota may modulate the response of invasive plants to prior nutrient fluctuations. Our results demonstrate that nutrient fluctuations in native plant communities can indirectly affect the later growth of invasive plants through changes in soil biogeochemical properties and microbial community structures.