Data from: Effects of arbuscular mycorrhizal fungi on plant invasion success driven by nitrogen fluctuations

Both enemies and mutualists play crucial roles in shaping plant invasion processes. Recent studies have suggested that resource fluctuations could indirectly promote plant invasion through higher trophic levels, such as enemies. However, the influence of mutualists like arbuscular mycorrhizal fungi (AMF) on plant invasion under nitrogen fluctuations remains untested. We conducted a pot-mesocosm experiment using a three-factorial experimental design to assess the individual and interactive effects of nitrogen availability, nitrogen fluctuation and AMF on invasive success of alien plants. We grew nine invasive alien species alongside five different native communities in pot-mesocosms. These were then subjected to varied nitrogen availabilities (low vs high), nitrogen fluctuations (constant vs pulsed), and AMF presence or absence within a sterile substrate. We found that pulsed nitrogen supply increased the dominance of invasive alien species in low-nitrogen availability, regardless of the presence or absence of AMF inoculation. However, in high-nitrogen availability, pulsed nitrogen supply only enhanced this dominance in pots without AMF-inoculation. This was tentatively evidenced by the three-way interaction among nitrogen-availability, nitrogen-fluctuation and AMF-inoculation treatments. Furthermore, the dominance promotion by nitrogen addition was greater than that by AMF inoculation. Synthesis and applications: Our findings present, for the first time, evidence that AMF may play a crucial role in mediating the promotion effects of nitrogen fluctuations on alien plant invasion. To better understand the invasion process of alien plants and evaluate their impact on native communities, future research should integrate abiotic and biotic drivers into a single framework. Furthermore, our findings underscore the importance of prioritizing habitats with higher nutrient availability and variability for protection against alien plant invasions.Funding provided by: Chinese Academy of Sciences*Crossref Funder Registry ID: Award Number:We conducted a pot-mesocosm experiment using a three-factorial experimental design to assess the individual and interactive effects of nitrogen availability, nitrogen fluctuation and AMF on invasive success of alien plants. We grew nine invasive alien species alongside five different native communities in pot-mesocosms. These were then subjected to varied nitrogen availabilities (low vs high), nitrogen fluctuations (constant vs pulsed), and AMF presence or absence within a sterile substrate. All data were collected from the pot-mesocosm experiment