Alameda County — This week marks the first anniversary of the start of the SCU Lightning Complex, one of the state’s largest fires in recorded history. In the aftermath of that conflagration, agencies like the East Bay Regional Park District (EBRPD) and Save Mount Diablo (SMD) are taking the opportunity to study the impact of fire on the local landscape.
A year into that effort, researchers are finding evidence of nature’s resilience throughout the study area. Trees that burned to stumps are coming back to life. Rejuvenated grasslands already hide much of the evidence of the fire, and rare wildflowers have sprung from the scorched earth.
“Our stewardship group went out right after the fire to implement some monitoring, so that we can see and track the impacts of the fire over time,” said Dina Robertson, EBRPD wildland vegetation program manager. “We’re measuring things like vegetation; water quality in livestock ponds; amphibian breeding and upland wildlife, which would include mammals, birds and snakes, things like that.”
In partnership with other agencies like the Contra Costa Water District, the EBRPD’s effort is expected to continue for three years. Observations made from this study will likely inform future environmental management policies and practices.
“The number of fires is increasing,” said Seth Adams, SMD land conservation director. “The size of the fires is increasing. The question is whether they are beneficial or whether they convert the whole landscape into a different kind of landscape — that’s what we’re paying attention to.”
The skies above the East Bay sizzled with lightning in the predawn hours of Aug. 16, 2020, while on the ground, the impacts of drought and heat left vegetation dry as tinder. Over the next three days, more than 10,000 lightning strikes were recorded in the state. Reports of fires arrived shortly thereafter.
Cal Fire’s Santa Clara Unit (SCU) took on responsibility for fighting the 20 fires that made up the SCU Lightning Complex. Cal Fire and local fire agencies spent untold hours over the next 44 days until the incident was declared 100% contained on Oct. 1. By that time, nearly 400,000 acres across six counties had burned. There were no reported deaths related to the fire, but 222 structures were destroyed.
“We had about 6,000 acres burn on park district lands,” Robertson said. “That was in the Ohlone Wilderness and Sunol Regional Park, and also to the north in Morgan Territory and Round Valley preserves.”
Despite the extent of the burn, the way it burned could possibly improve the ecosystem.
“Most of the fire that burned on our lands was moderate to low severity with a few places of high severity burns,” Robertson explained. “For the most part, it was not high intensity. Rather than seeing areas where things are decimated like you see in other parts of California, we still have quite a bit of live vegetation standing. We didn’t lose all our trees. We have a lot of oak woodlands in the area that burned — a lot of open rangeland. It was pretty spotty. Luckily, it burned in a way that is beneficial for the system.”
A team of SMD botanists discovered a population of fire poppies in a remote location in Morgan Territory Regional Preserve, marking the first time this rare species has been observed in that area. Fire poppies are called fire followers because their seeds can lie dormant in the soil for decades until a fire spurs them to germinate.
At the same time, the EBRPD research team has already seen blue oaks, manzanitas and other plant species sprouting from their burned stumps. Though portions of plants and trees above ground may have been badly damaged or destroyed by fire and heat, the vegetation did not die.
“I feel very good about a lot of the areas that burned, especially over in Morgan Territory where it burned super-hot on the ridge,” Robertson said. “There are tons of plants up there. So much came back from seed, as well as from stumps.”
No impact to water quality has been measured thus far, a fact that can likely be attributed to the relatively dry winter following the fire. With little rain running down burned hillsides, potential pollutants remain largely in place, a situation that could change if the coming winter brings heavy rains. However, Cal Fire has taken some measures to minimize erosion in the burn area and repair infrastructure.
“We did fire suppression repair,” said Ed Orre, Cal Fire unit forester, division chief. “Cal Fire is not obligated to do that, but we more often than not try to fix the things we broke fighting the fire. We try to repair the dozer lines and hand lines, so they’re set up for the coming winter, so that we don’t exacerbate any erosion.”
Looking at the entirety of the Diablo Range, Adams noted that fire recovery has, to date, varied depending on location.
“Regeneration in the Diablo Range, while it’s a real mosaic, it’s very different in different places,” he said. “From relatively good regeneration on the west side — understanding the Diablo Range is 40 or 50 miles wide — the west side has a little more water, so things have come back faster. Once you cross the first line of ridges, it drops down to 50%, 30%, 10% of regeneration. It’s a very dry period.”
While controlled burns have not been a big part of fire management in Alameda County, Orre said that Cal Fire officials are looking at plans to increase the use of prescribed burning to manage fire risk in eastern Alameda and Contra Costa counties.
“The SCU Lightning Complex was a positive fire as far as the ecology goes,” Robertson said. “It was low to medium with a little bit of high intensity. It burned off a lot of thatch and woody materials underneath our woodlands. I think it was a good fire. We got lucky. I would expect that over time, these areas are going to recover. It will probably not even look burned a few years from now. In the grasslands you can barely even tell they burned.”