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Monday, September 25, 2023

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'Outdoor Lab' Fuels Critical Environmental Research and Sparks Student Passion

SDSU students and faculty are advancing wildfire, water and flora research at Alvarado Creek.
By Kellie Woodhouse

“A site like this, from a scientific perspective, is an absolute gem purely because it is so accessible.”

Lush vegetation once covered the rim of Alvarado Creek, a modest channel a short walk from San Diego State University’s campus.

That was before a brush fire blazed through the area in mid-September.

Now the tributary and the land banking it, called a riparian zone, is host to a different kind of landscape. Scorched remains of plants clog the creek, a layer of chalky rubble sits atop a scarred bluff and the blackened spines of palm fronds offer little shade.

Where many might see devastation, SDSU engineering professors Alicia Kinoshita and Natalie Mladenov see a golden opportunity. 

“We call it an outdoor laboratory,” Kinoshita says while collecting soil samples near the creek.

“You have to learn to think on your feet a little bit, to get your nose out of the books,” she continues. “You learn all the theory and concepts in class, but it is invaluable to apply it in the field.”

Kinoshita studies the impact of wildfire in urban settings. She and her students consider how fire alters the landscape and contributes to erosion and flooding, and they investigate how wildfire management affects the environment.

On a recent afternoon, junior civil engineering major Ray Becerra helped Kinoshita and fellow students assess the creek after the September fire. They collected soil samples, which Becerra analyzes back in the lab, cataloging factors like organic content, particle sizes and shear strength.

His frequent visits to Alvarado Creek are his first opportunity to “put theory into practice” by working in the field, a critical competency for budding research scientists. 

“It’s exciting. We get to see the effects of the fire,” he says. “As a student, you need to focus on something, but you don’t exactly know where you are going to fit in. Fieldwork is great because you can get hands-on experience and see if you are going to like it right away.”

Mladenov studies water quality. Since Alvarado Creek is in an urban setting, vegetation and soil along the riparian zone collect chemicals and pollutants that run off from highways and nearby land. 

Working with public health professor Eunha Hoh, who studies environmental pollutants, Mladenov considers how these materials become even more problematic after a fire and how they flow into the creek when it rains, eventually ending up downstream. Her research could have critical implications for municipalities that source drinking water from surface water. 

An invasive issue

Invasive plants like fan palms, eucalyptus trees, smilo grass and arundo reed pervade the area. They cause blockages along the creek, slow water flow and occasionally lead to flooding. During a fire, invasive plants are exceptionally hazardous. Fire feeds off the dead fronds of palm trees and the oil of eucalyptus trees, and invasive grasses help spread flame.

SDSU’s Soil Ecology and Restoration Group
 (SERG), led by biologist Thomas Zink, restored a section of the tributary over the past three years by stripping the area of invasive species, allowing native plants like sycamore trees, willows and wild grape to thrive. During the recent brush fire, the invasive plants lit up like “matchsticks,” Kinoshita said, while the restored area largely resisted the fire. 

“It was a true experiment showing the benefit of the native vegetation,” Mladenov says. “As we try and restore more natural landscape to urban areas, we should really be thinking about the benefits of natives over non-native plants.”

The San Diego River Conservancy (SDRC) awarded SERG $900,000 this year to continue Zink’s effort to restore the creek and further Mladenov and Kinoshita’s research. A $500,000, three-year SDRC grant funded their initial work. Zink and his lab will spend the next two years clearing a 500-meter swath, including the site of the September brush fire, and returning it to its natural coastal sage landscape.

Graduate student Lauren Mathews finds the relationship between burn severity, vegetation and recovery after urban fire particularly compelling and has made it the subject of her environmental engineering thesis. 

“A site like this, from a scientific perspective, is an absolute gem purely because it is so accessible,” Mathews says as she uses a sub-meter GPS receiver to determine the exact location of sample sites near the creek. 

“A lot of these places are hard to access and you don't have this really nice temporal study,” she continues. “Here we can come anytime and that's novel.”

Partly because of its proximity, a wide range of faculty and students use the creek as a resource. 

Geography professors Hilary McMillan and Trent Biggs take their classes to the creek each year to teach students tenets of hydrology, like measuring stream flow. Biggs and recent geography doctoral graduate Luis De La Torre studied the creek bed’s ability to filter toxins from the water. Their results were the foundation of De La Torre’s 2019 dissertation. Homeland security professor Eric Frost and his graduate students use the creek for class projects, like creating emergency management plans in case of flooding. 

Senior engineering major Denise Garcia has worked in Mladenov’s lab for over a year, sampling and analyzing water samples at Alvarado Creek more than a dozen times. She once thought she would go straight into industry after college. Her work with Mladenov has sparked a new passion for research.

“I am the type of person who likes to go outside of her boundaries. That’s why I like research. There’s so much to expand on that people haven't discovered,” she says. “In the field, you have to solve problems and you have to think critically about what you are doing. You don’t get that kind of experience in the classroom.”

'Outdoor Lab' Fuels Critical Environmental Research and Sparks Student Passion
SDSU students and faculty are advancing wildfire, water and flora research at Alvarado Creek. (Photos: Kellie Woodhouse)