A fight at a recent city forestry committee meeting over tree removal could be a portent of things to come as Pasadena moves forward with plans for the Hahamongna Watershed Park.
New questions about what to do with the park’s non-native trees, as well as other ecological issues, have surfaced in the wake of the Station Fire, which burned 250 miles of land in the Angeles National Forest, including an area directly above the Hahamongna.
A small, but insistent group of community activists has already begun calling for more studies into the future of the park and believe city plans for the watershed – including removing non-native trees – should not go forward without more information about the fire’s impacts.
“We’ve seen animal populations devastated by the fire,” said resident Lori Paul, who is closely following the issue. “Even non-native trees are useful for (animals) … a lot of animals depend on these trees.”
City officials have been in discussions with the U.S. Forest Service, which is advising the city to adopt an entirely different approach – removing even more of the non-native trees.
The fear is that non-natives will begin spreading into recently burned areas, crowding out natural species that would normally grow there, said Rosa Laveaga, who directs the city’s projects along the Arroyo Seco.
Tim Brick, a biologist who works in the Arroyo Seco, believes opponents of removing the trees don’t have science on their side.
“The logic is quite the opposite of what they are saying,” said Brick. “It doesn’t make a lot of sense at all.”
Nevertheless, the city’s Urban Forestry Advisory Committee has sided with community activists, recommending last month against removing eight non-native trees in a popular walking area called Sunset Overlook.
“We basically didn’t feel we were qualified to make a decision on forest ecology,” said Chris Peck, who heads the committee.
More meetings on Hahamongna will be coming up soon. A master plan for 30 recently acquired acres in the north section of the park has been in the works for the last two years and will finally go before the City Council in January, Public Works Director Martin Pastucha said.
The council could still approve removing the non-native trees at Sunset Overlook – or anywhere else, since the forestry committee is only an advisory board.
Meanwhile, the Forest Service has been busy studying the impacts of the Station Fire on the burn areas above the park. Besides the potential invasion of non-native trees and vegetation, there are also concerns about debris slides and flooding from the Arroyo Seco, as well as the effects on local animal populations.
But despite the ecological changes from the fire, there are no plans to significantly alter the immediate plans for Hahamongna, nor the long- term plan for the park, said Pastucha.
That may be because city officials had already sought to address within the plan many of the issues and concerns raised by the fire, including the problem of non-native plants creeping into burn areas. City officials, for instance, have long considered removing non-native plants as the best policy for the area. Now that policy could be getting more urgency.
Another concern for biologists studying the burn areas is the potential for increased debris flows and flooding at the 1,200-space parking lot used by JPL employees, which is located very near the Arroyo Seco.
That parking lot is already scheduled to be removed as part of the city’s long-range plan. A smaller parking lot of 200 spots will be retained but farther away from the river. In its place would be a series of natural pond areas to help restore the habitat of fish and reptiles in the river.
The habitat restoration is important, said Brick, but the city will be powerless to stop the effects of the Station Fire on some animal populations.
A $2.5 million river restoration project completed last year by Brick’s group, the Arroyo Seco Foundation, re-established the habitat of a local fish called the Arroyo chub in two areas below the Hahamongna park. The fish, which once thrived in the river, was reintroduced into the area by the group last year.
Biologists studying the park say the fish now have little chance of survival because of the expected increase in mud and sediment that will flow into the river this winter when the rains begin.
“They are going to be wiped out,” said Robert Fisher, a biologist with the U.S. Geological Survey.
Trout farther up in the river also will be seriously threatened, he said.
Debris flows will also increase safety concerns for park users. There are dozens of trails used by hikers, bikers, and horseback riders, and some of them lead into the center of the park, along the river.
These issues will mean the city will need to be vigilant, said Pastucha, but the bottom line, he said, is that people will go where they want to in the park, regardless of safety warnings.
Forest Service lands just north of the park are already closed to the public. The city will be posting signs within the park warning people not to go in, said Pastucha.
But the city won’t bother trying to put up fences or other barriers, he added, because people will easily go around them if they want to.
“I don’t think there is a barrier that will stop people from going into areas if they want to go in,” said Pastucha. “We do have concerns about people getting in there, but all we can do is let people know it is closed.”