Tuesday, August 11, 2020
Aug. 11, 2020

Linkedin Pinterest

Mount St. Helens ecological research could help conserve, restore nature


LONGVIEW — The sounds of gusting winds, chirping birds and gurgling streams surrounded John Bishop as he and two students hiked to a cluster of willow trees near the south shore of Spirit Lake on a hot day last July.

But to hear the high-pitched squeak made by the subject of his decades-long study, the Washington State University Vancouver biologist had to hold one of the small, black and white beetles up to his ear.

The weevils, which burrow inside the willow trees, likely kicked back development of the trees on the Pumice Plain, Bishop said. However, he said he’s trying to learn if their “frass,” or poop, enriches the soil. It’s a classic ecosystem study, a look at how nature stitches together — and sometimes unravels — a new web of life.

“At times I may seem obsessed with insects, but I think it’s illustrating bigger principles,” Bishop said.

For the last 30 years, Bishop, 56, has studied the resurgence of life on the Pumice Plain after the May 18, 1980, eruption of Mount St. Helens left the area between the volcano and Spirit Lake a wasteland. The research has been built on by graduate students who may inherit Bishop’s work in the next several years. The studies have implications beyond the volcano and could uncover new ways to restore nature following other mass disturbances, and it could also inform the battle against climate change.

Bishop’s research is another example of how Mount St. Helens provides researchers a simple system to study how nature works without complicating factors.

“Think of it as a puzzle that doesn’t have so many pieces,” he said. “You can get a handle on things you can’t study in more developed (eco)systems.”

Studying the first plant life on the Pumice Plain

Bishop has been interested in nature from his first word — bird.

“I was always wanting to bring home living things. I was that kind of kid, and I grew up into that kind of person,” he said. “I’m the kind of person who wants to know how nature works. Mount St. Helens is that piece of nature I was lucky enough to stumble into and start working in.”

Like life on the Pumice Plain, Bishop’s career on the mountain started with the lupine, the first plant to spring up there after the 1980 blast. Last summer, the plant’s purple flowers carpeted large swaths of the area. Unlike many plants, lupine can grow in the volcanic soil because it can free up phosphorus bound in the rock, as well as convert nitrogen from the atmosphere into an accessible form.

“In the early 1990s, there were lupine patches and not much else,” he said. “In a place so extreme like this, only a few (plants) can handle it – like the lupine – which then helps create soil and allows other plants, like grasses, to grow.”

Bishop studied lupine genetics for his Ph.D. research in the summer of 1990. He began working at WSU Vancouver in 1998 and is now the co-director of the College of Arts and Sciences.

After watching an entire patch of lupine die one year because caterpillars were eating the roots, Bishop began studying what insects were doing and how they affect lupine and willows.

Willow trees were the first woody colonists on the Pumice Plain and are the subject of many of Bishop’s current experiments. Bishop said he first received a grant in 2006 to study the effects of the weevils on the willows. Although his most recent grant ended in 2018, Bishop and WSU Vancouver Ph.D. student Rebecca Evans maintained the willow plots over the summer by measuring the plants and collecting samples.

They measure the base of each willow within their 36 research plots and check for damage from weevils or other causes.

Bishop’s research found that animals (including insects) feeding on plants has a larger effect on ecosystem development than previously believed. For example, when the weevils eat the willows, they limit their size and spread, which cuts down on food sources for animals, shade for other plants to grow in, and nutrients from decomposing wood, he said.

“They’re important because those larger plants create nesting spots for birds, and insects eat it and they are food for birds,” Bishop said.

The trees and shrubs also help improve soil quality. Organic matter, including decomposing plants, improves soil structure, reduces erosion and increases food supply.

The 1980 blast left the soil on the Pumice Plain nearly sterile, and that has allowed scientists to track soil redevelopment over the past 40 years. They’ve found the volcanic soil is great for storing carbon, but they are not sure why, Bishop said. Maintaining carbon storage in the soil is important to combat climate change.

Evans is working with Bishop to try to answer that question.

Creating soil, preserving diversity

On that hot July day, Bishop and Evans sat among the flowers for a lunch break, surrounded by the lupine’s musty smell.

Like her mentor, Evans, 30, said studying lupine is how she got started researching on the mountain. However, her interest in ecology stretches back to high school and her undergraduate studies at Washington State University, when she worked restoring degraded habitats.

“I realized there’s a lot going on in soil,” Evans said. “I learned how soil is the base for an ecosystem. … It creates a dynamic ecosystem that provides beauty and services (such as) carbon storage, water, all these big pieces coming together that I didn’t know about before.”

Scientists still don’t know how soil is created or how nutrients in the soil affect fungi, carbon storage and climate change, she said. But Mount St. Helens provides a unique landscape to study these questions because the lack of “background levels” of nutrients and bacteria in the soil, Evans said.

“There are so few places we can study succession,” or the process of how a biological community evolves over time. “So this is pretty exciting,” she said.

Evans began work on Mount St. Helens during her master’s research from 2015 to 2017 investigating carbon and nitrogen in soils in an experiment Bishop set up in 2009. The research introduced her to what would become the focus of her doctorate research.

Now in her second year of doctorate studies, Evans is exploring how pollutants and invasive species can upset soil and ecosystem development. Specifically, she’s looking into how nitrogen pollution and the weevils alter soil development on the Pumice Plain.

Nitrogen is a naturally occurring element critical to a living organism’s abilities to make proteins, but too much of it can pollute the air, water, or soil. It can cause toxic algae to grow, impair air quality or harm plant growth, according to the U.S. Environmental Protection Agency.

Evans said she chose to study nitrogen because she sees nitrogen deposition, or the input of nitrogen from the atmosphere to the biosphere, as the next global change that could alter the Earth’s capacity to sustain life.

Human activities, such as burning fossil fuels and making fertilizers, have increased the amount of available nitrogen in the Earth’s ecosystems, according to a 1994 Royal Swedish Academy of Sciences study. This increase can affect carbon storage, lead to a nutrient imbalance in trees and a decline in biodiversity.

Evan’s studies attempt to link the biodiversity in the soil to how well the soil functions. Extra nitrogen in the soil can strip out micro-nutrients and cause plants to die, she said.

“Nitrogen really overall affects diversity… and we want to conserve diversity,” Evans said. “Everything has a purpose, and taking something out alters the ecosystem.”

Maintaining carbon storage in the soil is also important to combat climate change, she said. About one-third of the increase of carbon dioxide in the atmosphere is from the loss of carbon in the soil from land use change, such as clearing of forests and cultivation of land for food, according to a study published in the journal “Science.”

Mount St. Helens is a unique location to study this, Evans said, because she doesn’t have to worry about residual nitrogen or other factors complicating results.

“There are a lot of fundamental questions of how natural systems work that are hard to break down in a complex system,” Evans said, such as how nitrogen in the soil affects how carbon forms.

Understanding principles like that can help understand more complex systems, like how a forest comes back, Bishop said. The research could be used to learn how to avoid damaging nature or how to restore it, he said.

Regrowth of the landscape is a complicated process that takes centuries, Bishop said. Bringing on a new generation of scientists is necessary to continue the accomplishments of the first 40 years, he said.

“If we’re to understand how communities of plants and animals are constructed following such events, this is our best opportunity,” Bishop said. “So it’s important to replace the older generation of scientists to take advantage of this opportunity. It’s also important because young scientists bring new kinds of technology and often have new questions to ask, so they ensure that the science that goes on in this place continues to evolve.”

The next generation

Bishop has mentored graduate students for more than half of his career on the volcano. He said it’s important to bring them to Mount St. Helens to help them achieve their goals, as well as his own.

“It would be hard to study some of the interesting questions without these students,” he said. “Becca (Evans) is a great case in point. She has training in soil and ecosystems science and science related to nitrogen pollution, areas that I do not know a lot about, so she is able to address questions that help us understand the answer to basic questions.”

Bishop said it won’t be that many years until he retires, and he wants to see new scientists build on the research in new ways rather than just continuing his experiments.

Evans said it’s “amazing” to work on Mount St. Helens with Bishop as a mentor.

“I’m always pretty lucky to come out here,” she said. “Having John’s knowledge of the mountain, vegetation and history, and his connections has been great. … It’s exciting because he’s open to new things. Soils aren’t really his thing, but he says they’re important and that we should understand them.”

Although Evans doesn’t know exactly what she will do once she finishes her doctorate program, she said she would like to continue research at the volcano.

“If I had an opportunity I would take it,” she said. “It’s an amazing place. I’ve been invested in it. … I would have never guessed I would be working on Mount St. Helens, but now I don’t want to leave.”