Urban ecology checkup

Chico State students assess health of Chico’s creeks, trees and fish

Students of Mark Stemen’s Service Learning and Geography class walk around a puddle made up mostly of raw sewage in Little Chico Creek last summer.

Students of Mark Stemen’s Service Learning and Geography class walk around a puddle made up mostly of raw sewage in Little Chico Creek last summer.


A colony of bats roosts in Chico State’s Butte Hall, and word is that real, live salmon pass through campus via Big Chico Creek. And yet, many students and community members likely believe ecology and urbanization are unrelated subjects—that ecology is the study of what occurs only outside of city (or campus) limits.

Chico State student Lee Brisbine wants to change that. He’d like his peers to take a moment each day to appreciate the natural processes occurring all around them.

“Look down at the creek when you cross a bridge,” he suggested. “You might see a fish.”

Lee and a handful of fellow students presented on “urban ecology” during Chico State’s annual This Way to Sustainability Conference (March 26-27). The students all took Geology 506, Service Learning and Geography, taught by professor Mark Stemen. In the class, students were tasked with assessing the health of Chico’s urban ecology, measured by the city’s creeks, trees and fish.

As it turns out, you’d be hard-pressed to find a better urban ecology classroom than Chico’s outdoor environs. Consider the urban forest made up of about 30,000 trees, roughly 200 acres of natural landscape within city limits, and multiple waterways running through urban and residential areas. That’s not to mention the natural features of Chico State’s campus, shaded as it is by 220 species of woody plants and bisected by Big Chico Creek.

Also, there are bats—lots of bats. Finding the colony in Butte Hall was the first project undertaken by Stemen’s class.

“When Butte Hall was constructed, it was pieced together like any building in an earthquake zone; it can’t be rigid, it has to be able to move,” Stemen said. “So, you have about an inch and a half of space between these giant slabs of concrete. That’s where the bats are.”

Victoria Birdseye kicked off the presentation with the students’ survey of arundo, an invasive and highly flammable plant that grows thick along Chico’s creek beds, especially Little Chico Creek, and often into homeowners’ backyards. The students mapped the creek from Pomona Avenue to Highway 99, measuring arundo by height and width as well as assessing fire danger.

Particularly alarming were fire pits near shelters that homeless people had constructed from the arundo itself, often elaborately so. (The students referred to the structures as “arundo condos.”)

“Some of the homeless camps were very impressive,” said student Tina Lando. “The arundo, they turned it into wigwams. They’d have blankets, lounge chairs, shelving units.”

The survey yielded real results. Last fall, Stemen went before the Chico City Council to testify about the fire risk posed by the arundo infestations. The council approved Butte Environmental Council to write a grant to secure funding from the state Department of Water Resources and other agencies to eradicate the arundo.

It was during that survey that the class also came upon what’s been described as a “poop pond.” That’s right—on the otherwise dry creek bed, hidden by thick vegetation and the high banks of Little Chico Creek, students found raw sewage in a volume befitting the description of a body of water.

Stemen described gingerly walking around the pooling waste as “a real-life game of hot lava” where the consequence of falling was “having the worst day ever.”

At the time, the origin of the sewage was a mystery. But after the class provided city staff with GPS coordinates of the site, the source was determined to be an illegal connection to a storm drain made by long-ago tenants of the building that’s now home to Tin Roof Bakery and Café—seven blocks away from the outlet into the creek. The connection has since been fixed.

“It’s just so interesting that this was happening for so long,” Birdseye said, “right underneath our noses!”

To prepare for studying Chico’s urban forest, Stemen’s class covered Edward O. Wilson’s biophilia hypothesis, first introduced in 1984. Wilson defined biophilia as “the urge to affiliate with other forms of life.”

“People have coevolved with nature and natural things,” said student Daniele Baxter. “We have a biological need for connection with nature.”

Chicoans are lucky, then, to be connected to such a spectacular urban forest. And, as Baxter explained, the trees also sequester millions of tons of carbon emissions each year, filter storm drainage water and reduce energy usage.

In order to offset some of the high-profile tree fellings in Chico over the past few years, Stemen’s students planted native tree species in worthy areas. First, they planted valley oaks at the small park on Humboldt Road, across from a low-income housing development, and then more trees in the unkempt triangle of green space between Cypress and Pine streets near Little Chico Creek.

The class also tagged along with scientists from local environmental consulting company FISHBIO as they counted fish in Big Chico Creek. In the process, the students learned of the fragility of the salmon run that passes through Chico in search of cool waters in which to spawn.

Salmon hadn’t been officially sighted in the creek for years prior to 2014, when FISHBIO biologists discovered about a dozen spring-run chinook salmon in Salmon Hole. But the salmon’s migratory pathway from that point was blocked by the Iron Canyon Fish Ladder, which has fallen into disrepair.

“We have a healthy, native salmon run going through our town,” Stemen marveled. “Do you know how many towns in California or on the West Coast would love to say that?”

Previous classes taught by Stemen surveyed the effects of the Saturday farmers’ market on downtown businesses and established the community garden at Oak Way Park. And stay tuned: Next year’s curriculum is “informal geography,” i.e., yard sales, food trucks and tent cities.