Tree after tree in Bidwell Park is adorned with red, yellow and orange leaves this fall. Known as “City of Trees,” Chico has had trees as part of its history for a long time. Chico was designated an official “Tree City” by the National Arbor Day Association in 1984 and is home to hundreds of native and non-native tree species.
Trees are a part of Chico’s culture, and knowing how to identify them can help you better understand the environment you live in.
Roger Lederer, author of “The Trees of Bidwell Park” and former Chico State biological sciences professor, said there are about 130 species of trees in the park and he feels appreciating them is important.
“If we're going to save [Bidwell Park] and preserve it ... the best way to do that is get people to know what's in there and say, ‘Wow, this is pretty cool,’” Lederer said.
So what’s so cool about the city’s trees? Here's a look at the top three most common types to find out.
Maple
Trees belonging to the maple or acer family are the most common trees in Chico. They make up about 18% of the city’s nearly 35,000 trees.
There are three varieties of maple trees found in the city. The Bigleaf Maple is native to the area, while the Silver Maple and the Trident Maple were introduced and are non-native species. Lederer said most tree species in Bidwell Park are also considered non-native.
“They came from everywhere, from John Bidwell and from people just dragging stuff in, and from seeds blowing in from people's yards, and all kinds of other places,” Lederer said.
“Our native [tree] species are adapted to our climate. They're adapted to the soils in this place, and they are the most logical choice of what can exist in an uncertain future.”— Don Hankins, Chico State professor of geography and environmental studies
Each variety of maple has different types of leaves, but the Trident Maple is known for having small, 3-inch leaves with three points resembling a duck’s foot. During the fall, the Trident Maple’s leaves turn orange and red.
Lederer said that many non-native and invasive species are planted in the area for being pretty, like the Bradford Pear, which are considered hazardous for their falling branches.
“That's what a lot of people do, they plant things because they look good and they don't realize the secondary effects might not be so good,” Lederer said.
Chinese Pistache
One of these good looking non-native trees that can be easily spotted in Bidwell Park is the Chinese Pistache. It's a small and eye-catching tree with tiny sets of vibrant red leaves.
As its name suggests, the Chinese Pistache hails from China and makes up about 8% of the Chico’s trees.
“[Chinese Pistache is] a really showy plant, but it happens to be kind of invasive in the area,” said Don Hankins, a Chico State geography and environmental studies professor.
“[Valley Oak trees] become these multispecies, multigenerational condominiums that get filled with cavities that are inhabited by so many different kinds of animals. So every single one is really its own kind of thriving city by itself.”— Wolfy Rougle, planning and watershed program manager for Butte County RCD
While beautiful, these trees aren’t ideal, as they aren’t attuned to their environment like native ones, which are vital to Chico.
“Our native species are adapted to our climate,” Hankins said. “They're adapted to the the soils in this place, and they are the most logical choice of what can exist in an uncertain future.”
Oak
A critical native tree in the city is the oak. Trees belonging to the oak or quercus family are the second most common tree in Chico, totaling about 15% of the city’s trees. There are seven oak varieties in Chico, many of which are native to the area, including the Blue Oak, Interior Live Oak and Valley Oak.
“Down in Lower [Bidwell] Park, you're most likely to find the big Valley Oaks, so they have curvy but deeply indented leaves that aren't too big,” said Wolfy Rougle, the planning and watershed program manager for the Butte County Resource Conservation District. “They tend to grow pretty near water.”
These trees can also grow to more than 100 feet tall. In the early weeks of autumn, Valley Oak trees typically will turn yellow or light orange, then slowly turn brown as the season progresses. Rougle said the large trees often house ecosystems for animals like owls, bats and woodpeckers.
“They become these multispecies, multigenerational condominiums that get filled with cavities that are inhabited by so many different kinds of animals,” Rougle said. “So every single one is really its own kind of thriving city by itself.”
“Trees are talking to us all the time, whether we're listening or not, just through the shape of their leaves."— Wolfy Rougle, planning and watershed program manager for Butte County RCD
Oak trees are also considered fire resistant, meaning they have adapted over time to different patterns of fire. This includes both natural and man-made fire. Indigenous people would use fire partially to help keep areas clean from old vegetation and refresh plant life for food production, Rougle said.
“It would not be uncommon if you were here 200 years ago to see people burning underneath the big Valley Oaks of what's now at Lower Park every year or every other year,” Rougle said.
Hankins said that prescribed and cultural burns can still be used to maintain the ecological health of trees, which produce acorns that are vital for many different animal species.
“Including turkeys and deer, bears and things like that, but also those acorns are pretty important as a food resource, traditionally, for California Indian people as well,” Hankins said.
He said the fall is considered a good time to conduct prescribed burns for deciduous trees — or trees that drop leaves — due to weather conditions.
However, when wildfires happen during the spring and summer, like this year’s Park Fire, trees can face severe consequences.
Wildfires can decrease the reach of native plants in areas, change their water intake and their production of things like acorns. In the Park Fire, some oaks were burned above ground, leading to resprouting as the base of the tree.
“A lot of our deciduous oaks, like the Blue Oak, Black Oak and Valley Oak, have a little bit better chance of having an active canopy that will still kind of resemble the forest structure that was there prior to the fire,” Hankins said.
Forests with active canopies help reduce heat, maintain habitats and promote biodiversity.
Bidwell Park has seen a mix of fire effects in the Park Fire’s footprint, with some trees being protected while others burned. Fire will likely hit the park again, but Hankins said, prescribed burns can help.
Rougle said learning even the shape of a tree’s leaves can tell us how they might respond to fire. Different leaf types react to fire differently and require unique types of fire for mitigation.
“Trees are talking to us all the time, whether we're listening or not, just through the shape of their leaves,” said Rougle.
