In the wake of the most disastrous volcanic eruption in the history of the United States, scientists enlisted the help of an unlikely ally to regenerate life on Mount St. Helens’ barren slopes: gophers. Over four decades later, they were shocked to see that the burrowing rodents’ positive impact remains visible to this very day.
On May 18, 1980, Washington’s Mount St. Helens covered 22,000 square miles with 540 million tons of ash. A few years later, scientists unleashed gophers onto part of the lifeless mountainside for 24 hours, hypothesizing that the animals’ digging habits might dredge up beneficial microorganisms and give the ecosystem a regenerative boost—and they were right. Now, researchers following in their footsteps 44 years later are highlighting just how enduring innovative ecosystem-rescuing methods can be.
“They’re often considered pests, but we thought they would take old soil, move it to the surface, and that would be where recovery would occur,” Michael Allen, a microbiologist at UC Riverside who partook in the study, said in a University of California Riverside (UCR) statement.
In 1983, the areas around Mount St. Helens that the scientists had chosen for their gopher experiment were heaps of “collapsing slabs of porous pumice,” according to the statement, with just about a dozen plants and some struggling seedlings staging a weak comeback. Six years after the brief gopher intervention, however, the two plots of land hosted 40,000 thriving plants. In stark contract, the surrounding region was still mostly barren.
In just 24 hours, the gophers’ work seemed like magic. But the real secret? Microorganisms.
As the researchers predicted, the gophers had dug up communities of fungi and bacteria. Such microorganisms are essential to all ecosystems, and life itself, as they break down organic material, releasing vital nutrients back into the soil and atmosphere.
“With the exception of a few weeds, there is no way most plant roots are efficient enough to get all the nutrients and water they need by themselves. The fungi transport these things to the plant and get carbon they need for their own growth in exchange,” Allen said. Mycorrhizal fungi specifically “penetrate into plant root cells to exchange nutrients and resources,” according to the statement, and can protect them from harmful pathogens.
Gophers, a fossorial (or burrowing, hole-digging) species, spread a mix of soil microbes, seeds, and beneficial fungi from their droppings into new environments, the researchers explained in the study, published in the journal Frontiers in Microbiomes. This allowed for rapid regeneration of the environment after the cataclysmic environmental disaster.
The study also identified other helpful microorganism carriers. Pine, spruce, and Douglas firs from an old-growth forest on Mount St. Helens were covered in volcanic ash after the eruption, but were able to quickly grow back because of—you guessed it—helpful fungal friends.
“These trees have their own mycorrhizal fungi that picked up nutrients from the dropped needles and helped fuel rapid tree regrowth,” Emma Aronson, a UCR environmental microbiologist who also worked on the study, explained in the statement. “The trees came back almost immediately in some places. It didn’t all die like everyone thought.”
This stood in stark contrast to another area in the vicinity, which loggers had cleared of trees before the eruption. Without trees to drop needles or gophers to bring back crucial microorganisms, the area is still virtually barren over 40 years later.
“We cannot ignore the interdependence of all things in nature, especially the things we cannot see like microbes and fungi,” Mia Maltz, a mycologist at the University of Connecticut who led the study, said in the statement.
The shockingly enduring impact of a small intervention by tiny creatures offers inspiration for creative methods to save environments, even after extreme natural disasters.The gophers, however, couldn’t have done it alone, and the research highlights the power of cross-species teamwork operating beyond what’s visible to the naked eye.