When sizzling lightning storms peppered southwestern Oregon on the evening of Aug. 30, 1987, Dave Perry was already a well-respected forestry professor at Oregon State University.
But the forest ecologist, who had been teaching at OSU for a decade, says the nearly 150,000-acre Silver fire complex ignited by thunderbolts 20 years ago today taught scientists valuable lessons about the Klamath-Siskiyou forests.
"My jaw dropped nearly to my knees from what I saw," he recalled of a visit to the complex's still-smoking Longwood fire near Takilma in the Illinois Valley. "I was used to the fire dynamic in the northern Rocky Mountains, where old-growth forests are more susceptible than mature forests to crown fires.
"I found out the structure of the old-growth forests here is patchy enough that it doesn't propagate crown fires as readily as a more uniform homogeneous stand," he added. "The other thing was I had not a clue in hell that the hardwoods would be fire-resistant."
The 1987 fires definitely advanced ecological science, concurred ecologist Mike Amaranthus, who was then the soil scientist for the Siskiyou National Forest. The two ecologists had examined the immediate impact of the Longwood fire.
"It was a paradigm buster," observed Amaranthus, 51, who has a doctorate in soil biology.
"Until then, we didn't know that hardwoods could actually slow down a fire," said Amaranthus, who studied the impact of the fires on local forests. "The managed areas with the monocultures we were trying to produce had a type of canopy that really spread fire rapidly. The plantations went up like Roman candles."
Amaranthus later left government service to launch Grants Pass-based Mycorrhizal Applications Inc., a firm focusing on mycorrhizae, which interact with fungi in the soil to dramatically increase a plant's ability to take in food and water.
"This showed that Smokey the Bear wasn't the best thing for forests," he said of fire suppression over the decades. "There was so much fuel on the ground that it had created really explosive conditions.
"It also busted the paradigm that vast acreages of even-age conifer reproduction was a good thing," he said. "They are so susceptible to an intense fire. And our area is going to get fire."
The Longwood fire burned some 9,300 acres of private and national forestland, including everything from tree plantations to old-growth stands. The national forest portion, which is now part of the Rogue River-Siskiyou National Forest, also included OSU experimental plots.
"The Silver opened my eyes to things I wasn't aware of before," Perry said. "It helped us turn a corner conceptually. I went away and started writing about it."
Perry, 68, now professor emeritus of forest ecology at OSU where he taught for 20 years and currently teaches an online course on the ecology of sustainable resource management, recently revisited the area burned by the Longwood fire.
Joining him was Dominick DellaSala, 50, a forest ecologist who is executive director of the National Center for Conservation Science & Policy in Ashland. When the Silver fire complex began, DellaSala was designing a fire management plan for the U.S. Fish and Wildlife Department for the Bear Valley bald eagle refuge near Keno in Klamath County.
For them, the area burned by the Longwood fire, a microcosm of the larger 1987 fire complex, is an open book.
"You can see where the fire left some of the big trees," DellaSala observed of a national forest parcel just south of Takilma. "And the big trees it killed are now habitat for all kinds of wildlife. Eventually those trees will fall to the ground. That's tomorrow's soil."
He observed that knob cone pine, which depends on fire to release seeds from its dense cones, was now thriving.
"The snag forest provided the shade for a lot of those conifers to come back in," he said of young pine, fir and cedar. "This looks like it was a healthy burn in terms of the ecology."
"The shade of the standing dead and standing live is important on these kinds of sites to get regeneration back," Perry said. "And the burn was hot enough to stimulate these shrubs coming back."
Studies have shown that shrubs support soil organisms that conifers depend on, he explained. For instance, he noted that madrone stimulates nitrogen fixation in the root zone of a fir.
"That's very important because a lot of nitrogen gets volatilized in these fires," he said. "So anything that comes back that will pump more nitrogen into the system becomes very important in the ecological recovery. For reasons we don't yet understand, a madrone will stimulate that happening in the root zone of a Douglas fir."
Perry later pointed out snow brush growing under an old-growth fir tree whose thick bark had been blackened at the base by the fire.
"That's a nitrogen fixer," he explained. "Its seeds will stay buried in the soil for hundreds of years. They are triggered to germinate by heat. When a fire comes through, the snow brush will pop up and start pumping nitrogen back in."
DellaSala acknowledged that many foresters may look at the site and see hardwoods and other shrubs as competition for the conifers.
"They would want to wipe out this hardwood-shrub understory," he said. "But if you look at it through a different lens in terms of the forensics science of ecosystems that come back from fire, it is all related, all interconnected.
"There is a symbiosis going on between the hardwoods and the conifers," he added. "There is stuff going on below ground that contributed to this site coming back to become a forest."
While the two scientists agreed on most of what they saw, they quibbled over some of the finer points.
For instance, while Perry believes the severity of the fire depends on whether the stands are mixed or uniform, DellaSala feels that terrain and climate often have more to do with five behavior than vegetation.
"In the case where you have such complex terrain, when you combine that with drought and high winds we were experiencing on the (2002) Biscuit fire, those become the driving factors in fire behavior in those situations," he said.
Both agreed wildfires ultimately benefit the landscape.
"It is what is making them, in part, as rich as they are on the global scale," DellaSala said. "That's a hard message to get across to folks because you have to look ahead of what these systems are going to look like 10 or 20 years from now."
Reach reporter Paul Fattig at 776-4496 or e-mail him at firstname.lastname@example.org.