San Diego's frequent fires endanger native plants

The view from Pine Valley

Fires make David Hogan nervous. It's not because he's afraid his Pine Valley house will burn down. It's because after every fire in Southern California, politicians start clamoring for reduction of the "fuel" that covers the hillsides. Case in point: Senator Dianne Feinstein's October 26 announcement that she planned to seek $775 million of federal money to be used in part for "hazardous fuels reduction" in Southern California. In her letter to the chairmen of the House and Senate Appropriations Committees, Feinstein wrote, "We believe that it is critical to make a substantial and immediate investment to expand fuels treatment...." Bad idea, says Hogan, who runs the San Diego County branch of the Center for Biological Diversity. Controlled burns of native chaparral -- Feinstein's "hazardous fuels" -- will only encourage the growth of nonnative grasses, which ignite much more easily than the native chaparral.

Well over six feet tall, clad in blue jeans, a charcoal short-sleeved Dickies button-down, an Indiana Jones hat, and black wrap-around sunglasses, 37-year-old Hogan looks like a combination of hipster and outdoorsman. He stands in the Park and Ride lot in the northwest quadrant of the intersection of Interstate 8 and State Route 79 near Descanso, pointing to a pair of hills a quarter mile to the north. Highway 79 runs between them. The hill to the east of the road is covered in a green blanket of chaparral. The hill to the west is dotted with green plants. But between the plants are dead grasses. "There's very little difference between those two hills," Hogan says in a basso profondo speaking voice. "They both face south and have the same exposure. They're at the same elevation. But the one to the west of the road burned in the Cedar Fire in 2003. The one to the east hasn't burned since the Laguna Fire in the early 1970s. That's the kind of recovery you get over 30 years. There's a lot more habitat value on that east hill than there is on the west hill. If that west hill doesn't burn again, it will have that nice, lush coat of vegetation on it in 30 years, like the hill across the road has."

If it does burn again? "It will be covered in exotic weed grasses that are much more susceptible to fire."

To illustrate, Hogan turns to face a triangular cow pasture bordered by I-8 on the south, the lush hill to the north, and Highway 79 to the west. Nothing's alive in the pasture. It's covered in dead grass that has dried to a beautiful golden color. "This pasture is a good example of what happens with disturbance, whether it's from cows, from fire, or freeway construction. That whole slope by the off-ramp of the freeway, that's a manufactured slope that was filled and compacted when they put the freeway in. That's why it's all covered in exotic weeds. All the golden grass in the cow pasture is exotic, or nonnative. The golden hills of California were imported," Hogan says, chuckling.

"Five hundred years ago, bottomlands like that would have been full of oaks and native grasses like the buckwheat we see here." He bends down and with a long-fingered hand caresses the buff-colored blossom of a clump of buckwheat growing next to the parking lot's entrance. "In the spring, you'd have lots of annual herbs and wildflowers. But over time, because of grazing, that area has converted to the exotic grasslands. The conversion to exotic grasses hasn't happened as quickly on the steeper slopes, because you haven't had a lot of grazing on the slopes. It's just not very conducive to grazing. It's steep and it's thick with vegetation. But as the frequency of wildfires has increased significantly over the last 50 to 100 years, we're starting to see the same kind of conversion that happened 200 years ago with grazing, but up on the steeper slopes too.

"It's all about competition," Hogan explains. "When an area burns too often, as much of San Diego has, you're setting the native plants back -- the shrubs that take 30 years to recover and reach maturity again to where they're setting seed and vigorously resprouting roots. But when you're knocking them back that frequently [with fire], you're giving a competitive advantage to the exotic weeds and grasses, which only take one year to mature. Many of these are called annual grasses because they only take one year to reach maturity and set seed. Then it starts this negative cycle where, after an area burns too often and these invasive weeds start to spread into that area, they're actually much more flammable than the native shrubs and are more likely to burn again -- from a carelessly tossed cigarette butt, lightning, kids playing with matches, whatever it is. The fires start again and set the native plants back again. The exotic grasses are very tolerant of fire. They come back the next year with the first rain. Many of the areas that we saw burn in 2003 and that burned again last week are going to have beautiful carpets of green come spring. But it's all exotic weeds."

Five miles north up Highway 79, then two or three miles east on Old Highway 80, Hogan pulls his pickup onto the dirt shoulder on the south side of the road and hops out. He points to the 500 feet of hillside looming up on the south side of the road. "This is Guatay Mountain," he says. "It's an area that's never burned in the recorded history of European settlement of San Diego County."

Thick, green foliage ten feet high covers the mountainside from road to the mist-shrouded peak. Four or five stands of 25-foot conifers dot the mountain, about a dozen trees per stand. "That's a really unique and endangered conifer called the Tecate cypress," Hogan explains. "It's even rarer than the Torrey pine. It only grows in San Diego County, and only in two spots: here on Guatay Mountain and in one place on Otay Mountain.

"This hillside is a classic example of what old-growth chaparral should and could look like. Many areas of mature chaparral look like this when they haven't burned in a long time."

Bending down, Hogan runs his fingers through the blades of a clump of grass. "This is a native grass called Stipa. It would have been the dominant plant that grew in meadows and valleys that we drove past around Descanso that are now covered in exotic grass due to grazing."

Hogan points out some of the other native species growing on the hillside -- scrub oak, mountain mahogany, coffee berry, and manzanita. "This hillside is what's called hard chaparral," he says. "When it's mature, a person can't walk through it unless he's on his belly crawling. It's one of the most difficult kinds of vegetation to get through. There's another kind of chaparral that's referred to as soft chaparral, or coastal sage scrub. It's much more common close to the coast. It's the kind of vegetation that dominates a lot of the flatter areas of Torrey Pines State Reserve and Mission Trails Regional Park. It very rarely gets higher than waist high, and there's usually enough space between plants so you can walk through it."

Across the road, on the north side, the view is very different. There are native plants growing there. But unlike the junglish growth on the south side of the road, the north-side natives are spread out, and golden, strawlike grasses cover the ground in between them. Hogan crosses the road to the north side. "This side burned in the Cedar Fire," he explains, "and these exotic grasses grew up in the burned areas. And look at this," he bends over and easily pulls up a clump of 18-inch blades of bone-dry grass. "If you were going to start a campfire, this is what you would put under the wood as tinder. You could start this literally with a spark and a little breath to blow it into a fire. That's exactly what happens during the Santa Anas. You get a cigarette butt, you get a spark from someone welding, kids with matches, whatever it is, it flies into this stuff, you have the high winds, and the next thing you know, you have the Cedar Fire. This has a much lower ignition temperature than the native plants and grasses growing on the other side of the road."

Hogan's hope, and his work, is to get the people he refers to as "decision makers," such as Dianne Feinstein, "to realize the thing to do to protect people from wildfire is not to try and eliminate all of these 'fuels' or 'brush,' as they call them, but to leave it alone and focus instead on where people live, most importantly on using fire-resistant construction materials and maintaining reasonable defensible space around where they live and around transportation corridors so people can evacuate safely. Really, they should try to focus in on where people live, instead of trying to modify an entire landscape and, in so doing, ruining that natural landscape and, ironically, creating the greater fire risk."

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