Data from: Symbiotic soil fungi enhance resistance and resilience of an experimental grassland to drought and nitrogen deposition

Ecosystem stability is threatened by multiple global change factors such
as drought and elevated nitrogen deposition. Yet, it is still poorly
understood whether soil organisms can buffer against such perturbations.
Here we focus on arbuscular mycorrhizal fungi (AMF), a common and
widespread group of soil fungi. AMF form symbiotic associations with the
majority of terrestrial land plants and promote a range of ecosystem
services including plant production, diversity and nutrient cycling. We
tested whether AMF have the ability to enhance the resistance and
resilience of plant communities under soil moisture deficit (hereby
drought) and nitrogen deposition. Grassland microcosms with 11 different
plant species were established with and without AMF and exposed to
elevated nitrogen levels and to an intermittent period of drought. Drought
strongly reduced plant productivity and nitrogen cycling, but had limited
effects on plant diversity. Nitrogen enrichment reduced plant diversity
and increased nitrogen leaching and N2O emissions. The presence of AMF
enhanced plant productivity, plant diversity, and reduced nitrogen losses.
AMF facilitated the resistance of plant productivity and nitrogen cycling
to drought and the recovery of the plant community structure back to its
pre drought state. Furthermore, AMF also mitigated the adverse effects of
nitrogen enrichment on the resistance of multiple ecosystem functions to
drought. Synthesis. Our work highlights the integral role of AMF for the
stability of ecosystem functioning; AMF are not only able to promote
resistance to harsh conditions of global change, but also improve
resilience by enabling plant communities to recover. These findings
underline AMF’s insurance capacity to buffer ecosystems against global
change.