In this post our Reviews Editor, Jason Fridley, highlights three papers from the first Grime Reviews series that discuss aspects of plant-pathogen interactions and their role in community and ecosystem dynamics. In Responses of plant–pathogen interactions to precipitation: Implications for tropical tree richness in a changing world (2020), Valerie Milici and coauthors investigate relationships between rainfall and rare species advantage in tropical forests as mediated by phytopathogens. In Do soil-borne fungal pathogens mediate plant diversity–productivity relationships? Evidence and future opportunities (2020), Jasper van Ruijven and coauthors revisit evidence that experimental biodiversity effects are driven by negative density dependence from species-specific fungal pathogens. And in Roles of leaf functional traits in fungal endophyte colonization: Potential implications for host–pathogen interactions (2021), Marcia González-Teuber and coauthors discuss how plant leaf traits associated with the leaf economics spectrum also mediate fungal endophyte communities, with likely consequences for disease dynamics. 

These reviews highlight the increasingly recognized role of fungal and oomycete communities in the structure and function of plant communities, and that the impact of environmental change on plant populations depends both on the autecology of both plants and their symbionts. For example, Milici et al. suggest that one of the ways in which reduced rainfall in the tropics may diminish plant diversity is to reduce ‘splash’ dispersal of spores of species-specific pathogens; such pathogens often contribute to Janzen-Connell effects that foster rare-species advantage. In much the same way, van Ruijven et al. suggest factors that influence the transmission and specificity of fungal pathogens drive the strength of diversity-productivity relationships, with ramifications for ecosystem carbon dynamics under climate change. González-Teuber et al. point out that leaf traits often associated with environmental gradients -such as nutrient content – also influence the composition and behavior of fungal endophytes, which may shift from beneficial to pathogenic as leaves change in structure and chemical composition. Although much remains unknown about the specificity of plant-fungal interactions both above- and belowground and their sensitivity to multiple global change drivers, these Grime Reviews are a great starting place for ecologists working at the vanguard of these issues.

Stay tuned for the next set of papers in the Grime Reviews series in 2022: What can remote sensing do for plant ecology?