By Air, Rain and Land: How Microbes Return After a Wildfire
Published:20 Oct.2023 Source:American Society for Microbiology
A study published this week in mSystems suggests that dispersal -- through air or rain, for example -- plays a major role in microbial succession after a destructive fire. Researchers at the University of California, Irvine, spent a year tracking how bacterial and fungal communities returned to the leaf litter in a burned field. They found that the emerging microbial communities in the soil surface changed with the seasons and the reappearance of plants, and that the assembly of those communities was largely driven by dispersal.
The risk and extent of big, ecological disturbances like wildfires have been increasing in the last few decades.
The intense heat produced during a wildfire alters the chemical composition of the leaf litter, where microbes reside, and can shift the microbial communities in an ecosystem.
The researchers looked at 2 ecosystems that had been affected by the fire: a semi-arid grassland and a coastal sage scrub. To study the movement of microbes, they used 4 configurations of dispersal bags. For the first, they used burned leaf litter to fill small porous pouches that allowed microbes to pass in and out. For the second, a control group, they sealed leaf litter in bags that did not allow movement in or out. The third configuration was a porous bag filled with glass slides, to collect microbes as they moved through, and the fourth, another control group, included closed bags with glass slides.