This article, by Whitney Brown, is part of a series highlighting members of the Office of Sustainability’s Experts Database. In a collaboration with instructor Hannah Monroe’s course, LSC 561: Writing Science for the Public, students interviewed campus sustainability experts and produced short feature stories.
How is fertilizer made from decaying plant matter? Assistant professor Dr. Emma Hauser, who started in the summer of 2024 in the Department of Forest and Wildlife Ecology, learned this in high school while interning on a farm, and it opened her mind to the magic of soil. This passion is now the foundation for the Hauser Lab’s research into roots and soil ecosystems.
A whole world that relies on and influences carbon cycling through the breaking down and sequestering of carbon lives in the soil under our feet. Plant roots are vital in the process of moving carbon through the earth, and the Hauser lab focuses on the differences in nutrient dynamics between forest ecosystems. Learning about the soil and plant roots can help develop ecosystem management that adapts to changing climates, ultimately impacting Earth’s future.
How nutrients move through a healthy ecosystem is not completely known, and even less is known about how nutrients move through an ecosystem that is recovering from human activity. The Hauser Lab focuses on precisely this topic: how humans have impacted the Earth, especially in ways that are not visually obvious, such as in the root systems below ground.
“This means coming to terms with the fact that we as humans do inherently have some interaction with the natural world and will have an impact on it, but that doesn’t necessarily have to be bad,” says Hauser. This interaction can be simple, like taking a walk through a park, or it can be more complex, such as clear-cutting a forest.
Hauser previously compared an old-growth or primary forest that was 200 years old to prior agricultural land that was now an 80-year-old forest. Above ground, the plant growth was comparable, but below ground, it was a different story. The roots in the secondary forest weren’t as deep as the primary forest, which could cause the storage of nutrients to be shallower and carbon to cycle faster.
We rely on plants to process the carbon dioxide we make, but what happens when roots aren’t deep and plants don’t store as much carbon? An excess of carbon in our atmosphere and a warming climate.
Many of the functions that roots perform underground involve storing carbon and holding water. If root volume decreases, the abundance of carbon and available water in the soil also decreases, which affects water patterns and the water available to plants. If reduced root coverage leads to drier water cycles, fire intensity is likely to increase. Conversely, more extensive root systems can enhance water retention.
The Hauser Lab is currently examining the lasting impact of humans in and on the ecosystem below ground and conducting research that could lead to ecosystem management that is more climate-adapted. She wants to delve further into her past research of studying different types of second-use forests, or forests planted in areas previously used for agriculture. She plans to start in northern Wisconsin, where previous researchers determined what makes a forest an old growth forest. They added indicators, such as canopy gaps and deadwood on the forest floor, to secondary forests.
The transformation of this forest has been in progress for almost 20 years, and now is an ideal time to study the differences. Hauser plans to examine the carbon storage, plant nutrient availability, and overall growth of the different types of forests that have been created. This research could help develop new forest management practices to promote forest growth and fire prevention.
Hauser learned during her undergraduate degree that “Earth will go on regardless of us, it’s been through all these ages where it was much hotter, much colder, times when we maybe couldn’t have survived, but the earth is still doing what the earth has done.” The research from this lab and their goal to learn how the underground ecosystem works offer a bright spot in our future survival.