Michael Allen, a University of California-Riverside Microbiologist, sent two Gophers to spend just 24 hours on the barren side of Mount St. Helen in 1983, 2 years after the devastating eruption. Yet, 40 years on, the benefits they gave the landscape can still be seen.
On the clear morning of 18th May 1980, the Mount St. Helen volcano, which was thought to be dormant, erupted, spilling molten lava down her sides and sending ash into the air for days. Still the deadliest eruption in US history, it claimed the life of at least 57 people and left the surrounding landscape nearly lifeless.
“The blast zone covered the mountainside with very thick ask. I mean, ash that’s so thick that it could bury a car,” says Miz Maltz, lead researcher of a new study looking at the site 40 years on. For the years following the disaster, the plains surrounding the crater remained desolate. The side of the volcano was covered with collapsing pumice rock slabs and cooled lava. Little vegetation was able to grow in the harsh conditions.
“[The soil] contained no measurable carbon (C) or nitrogen (N),” reports Maltz’s study, nutrients which are essential for plant life to survive.
Yet, the future of the site changed in 1983, when Allen decided to release two Gophers into sectioned-off areas for 24 hours.
“We thought they would take old soil, move it to the surface, and that would be where recovery would occur,” reflects Allen, “we were just testing the short-term reaction.”
When he returned with his team of researchers 6 years later, they were stunned by the results. Within the gopher plots, “there were 40,000 plants thriving”, while the surrounding land remained barren.
But how did such a short interaction have such a lasting impact on a devasted landscape?
“With the exception of a few weeds, there is no way plant roots are efficient enough to get all the nutrients and water they need by themselves,” says Allen, “[Mycorrhizal] fungi [in the soil] transport these things to the plant.”
However, after the blast, the remaining topsoil did not contain a microbiome with enough fungi to support plant growth.
When the gophers were introduced, “they brought mini ecosystems along with them.” As they dug, they brought rich soil from deep under the ash to the surface and incorporated the fungal spores, soil, and seeds from their habitat into it.
After this interaction, the ground was able to continue to recover and “support plants in getting established” in these plots, while surrounding areas remained desolate.
This example underscores “the interdependence of all things in nature, especially the things we cannot see like microbes and fungi,” says Professor Maltz. This principle should be remembered when “restoring disturbed landscapes” across the world.