On May 18, 1980, the eruption of Mount St. Helens released 1.5 million tons of sulfur dioxide into the atmosphere, while the pyroclastic lava flow burned virtually everything within a 230-square-mile radius. Three years later, wildlife experts enlisted a team of local helpers for just 24 hours to accelerate environmental recovery in the area. But these were not human volunteers; they were gophers. And while analysis later that decade showed that the rodents provided an ecological benefit to the area, recent research published in the journal shows: Boundaries in microbiomesindicates that their regional influence is still visible today.
The first phase of the experiment began in 1983. At that time, a team including Michael Allen, a microbiologist at the University of California, Riverside, took a helicopter to an area that had previously been reduced to porous pumice by the volcanic eruption. According to one UCR profile on November 5, Allen and his Utah State University colleague James McMahon released “a few local gophers” in two areas known as the Pumice Plain and Bear Meadow. Although these spaces contained only a handful of struggling plants that likely grew from seeds dropped by birds, the gophers were allowed to do what gophers do best for 24 hours.
[Related: After Mount St. Helens erupted, scientists fought to preserve its devastation.]
“They are often considered pests, but we thought they would bring old soil to the surface, and recovery would occur there,” Allen explains. The team hoped that the animals could especially help bring vital, fertilizing microorganisms such as endosymbiotic rhizobial bacteria and mycorrhizal fungi to the surface.
“With the exception of a few weeds, most plant roots are in no way efficient enough to get all the nutrients and water they need on their own,” says Allen. “The fungi transport these things to the plant and in return receive the carbon they need for their own growth.”
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Their hopes came true. When they returned six years later, Allen and McMahon noted that the rodents’ work resulted in approximately 40,000 healthy plants in the Pumice Plain and Bear Meadow, as well as the return of native gopher populations. Meanwhile, nearby areas without gophers remained largely inhospitable to flora. More than four decades later, new soil samples from the same regions still indicated better fungal and bacterial abundance than the areas where ground squirrels did not live. The team, including mycologist Mia Maltz, hope their research can highlight the importance of connected, resilient, natural ecosystems.
“We cannot ignore the interdependence of all things in nature, especially the things we cannot see, like microbes and fungi,” Maltz said.
“In the 1980s we were just testing the short-term response,” Allen added. “Who could have predicted that you could throw a gopher in there for a day and see a residual effect 40 years later?”