Biodiveristy and Ecosystem functioning

The decline of global biodiversity caused by climate change and human activities poses a significant threat to ecosystem functioning. To effectively manage and predict ecosystem functioning under these global changes, it is crucial to understand the links between biodiversity and ecosystem functioning, as well as the underlying mechanisms.

Numerous studies have demonstrated that both plant-pathogenic and beneficial microbes play a role in shaping the positive relationship between plant diversity and productivity. The rationale behind this relationship is that the negative impacts of pathogens can be diluted, while the positive effects of beneficial microbes can be enhanced by increasing plant diversity. However, most studies have focused on a single microbial guild either aboveground or belowground, overlooking the comprehensive understanding of microbial contributions to ecosystem functioning.

In the summer of 2020, we conducted an experiment in which we applied microbial inocula collected from leaves and soils in the field to plant leaves and soil in a controlled greenhouse setting with a herbaceous plant community.

We found that microbial inoculation of leaves led to reduced plant productivity at lower levels of plant diversity, thereby promoting positive diversity-productivity relationships. In contrast, microbial inoculation of soil alone did not have a significant impact on plant productivity, but it counteracted the effects of leaf inoculation and weakened positive diversity-productivity relationships induced by leaf microbes.

Using sequencing technique, we found that soil inoculation may introduce arbuscular mycorrhizal fungi and leaf inoculation may induce plant pathogens.

These findings suggest that the effects of leaf pathogens on plant productivity can be compromised by the presence of mycorrhizal fungi, highlighting the importance of considering plant microbiomes as a whole to fully comprehend the microbial impacts on plant diversity-productivity relationships.