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.