Extreme rainfall affects assembly of the root‐associated fungal community

Abstract

Summary Global warming is resulting in increased frequency of weather extremes. Root‐associated fungi play important roles in terrestrial biogeochemical cycling processes, but the way in which they are affected by extreme weather is unclear. Here, we performed long‐term field monitoring of the root‐associated fungus community of a short rotation coppice willow plantation, and compared community dynamics before and after a once in 100 yr rainfall event that occurred in the UK in 2012.Monitoring of the root‐associated fungi was performed over a 3‐yr period by metabarcoding the fungal internal transcribed spacer (ITS) region. Repeated soil testing and continuous climatic monitoring supplemented community data, and the relative effects of environmental and temporal variation were determined on the root‐associated fungal community.Soil saturation and surface water were recorded throughout the early growing season of 2012, following extreme rainfall. This was associated with a crash in the richness and relative abundance of ectomycorrhizal fungi, with each declining by over 50%. Richness and relative abundance of saprophytes and pathogens increased.We conclude that extreme rainfall events may be important yet overlooked determinants of root‐associated fungal community assembly. Given the integral role of ectomycorrhizal fungi in biogeochemical cycles, these events may have considerable impacts upon the functioning of terrestrial ecosystems.

Community structure and functional group of root‐associated Fungi of Pinus sylvestris var. mongolica across stand ages in the Mu Us Desert

“…In contrast, many environmental factors frequently vary with changes in soil pH, which is considered to have the most definitive impact on soil fungal community composition (Barnes, Gast, McNamara, Rowe, & Bending, ). However, there were no significant correlations between the fungal communities in P. sylvestris roots and soil pH (Table ), which may be because fungi are less sensitive to pH changes and have a wide optimum pH range, without significant inhibition of their growth in pH outside this range (Rousk et al, ).…”

Cross‐scale integration of mycorrhizal function

“…Comprehensive ecological studies in drought‐prone environments (Castaño et al ., ; in this issue of New Phytologist , pp. 1211–1221) and after an unusually strong flooding event (Barnes et al ., ; in this issue of New Phytologist , pp. 1172–1184; see also the Commentary by Johnson, ; in this issue of New Phytologist , pp.…”

“…The increasing realization of the importance of plant–soil feedbacks in ecosystem dynamics puts mycorrhizal symbiosis in focus of the much wider research community interested in global change and land use. Of course, the relationship between mycorrhizal symbiosis and global change is also bidirectional (Barnes et al ., ; in this issue of New Phytologist , pp. 1172–1184; Castaño et al ., , pp.…”

Water, water everywhere … but how does it affect the functional diversity of ectomycorrhizal fungi?

“…This is of concern particularly as altered rainfall is consistently predicted to result from climate change, a fact seemingly exemplified by the numerous unseasonal rainfall events that have occurred in the UK and elsewhere in recent years. These events can, however, provide natural laboratories, and it is pleasing to see Barnes et al . embracing such an approach in this issue of New Phytologist (pp. 1172–1184).…”