NASA Flight Poised to Map Alarming Dieback in Hills
NASA plans to fly a high-altitude reconnaissance plane, a descendant of the U-2, over the San Fernando Valley and nearby areas today to map the death of wild vegetation in the Santa Monica Mountains and elsewhere.
The death of the vegetation is worrying fire officials increasingly as the annual brush-fire season begins.
The flight, by an ER-2 from the NASA base at Moffet Field near San Jose, was to have been carried out Monday, a NASA spokesman said, but was postponed because of high clouds obscuring the area.
The clouds were expected to be gone today, NASA said.
Flies at 60,000 Feet
The plane was scheduled to fly over the San Gabriel and Santa Monica mountains at 60,000 feet, taking photographs on regular, infrared and heat-emission-sensitive film.
The ER-2 is the NASA “earth resources” model of the Air Force’s Lockheed TR1-A, an advanced version of the U-2 spy plane that Francis Gary Powers was flying when shot down over the Soviet Union.
The “dieback” of wild brush, from causes that are still being investigated but appear to be related to the weather, is worse than was feared at first, County Fire Department Capt. Scott Franklin said Monday.
Estimates of the amount of dead vegetation run from 100,000 to more than 200,000 acres. Fire Department officials have estimated that the dieback may have created as much as a million tons of dead wood to feed fires on mountain slopes this summer.
Patches of Deadwood Widen
Franklin said that the problem has spread to mountain neighborhoods of Los Angeles, and that affected patches are growing larger.
Early this spring, Franklin said, “We’d identify it in two- or three-acre parcels, and now it’s showing up in parcels of from 100 to 500 acres.” Although not all vegetation has died in such parcels, he said, there is “significant dieback,” estimated at 30% of the brush in some places.
Most of the previously identified dieback zones were in the San Gabriel Mountains, where the Angeles National Forest is situated, and in the large open spaces of the Santa Monica Mountains west of the San Diego Freeway.
“Now it’s all through the Santa Monicas” in the heavily residential area to the east of the freeway, he said. “I flew over the mountains with the city Fire Department last week and we found it all the way from Sherman Oaks to the Hollywood Hills,” stretching into Griffith Park.
“I’m positive that (damage) wasn’t there earlier this year,” he said.
Coastal Areas Healthy
Coastal areas, and canyons which receive a flow of moist air from the ocean, show few signs of the dieback, he said. That fits with theories by U.S. Forest Service researchers that the dieback is caused by the shortage of rain this year, after several years of heavy winter rainfall that encouraged wild brush to grow too large to cope with a dry year.
Some researchers also say that the heaviest loss appears to be in areas where the vegetation is most exposed to polluted air, raising the possibility that drought-weakened brush has lost a resistance to smog that protected healthier brush in wetter years.
Officials are worried not only about the size and speed of movement of brush fires in the coming season, Franklin said, but they are particularly worried that fires fed by deadwood will burn at much higher temperatures, worsening the mud slide problem when heavy rains return.
“Hotter intensity fires do more severe soil damage,” Franklin said, particularly if the surface soil is heated to a temperature greater than 600 degrees Fahrenheit.
Fear of Mud Slides
The seeds of some vegetation live unharmed through lower-temperature fires, and some wild vegetation, including wild lilac, has even evolved so that its seeds benefit from the usual brush fires. But higher-temperature fires not only “cook all the seeds in the soil” and prevent regrowth, he said, but also change the characteristics of the top layer of soil, so that it becomes more likely to wash away in a river of mud in the next downpour.
The county Fire Department is planning controlled burns--brush fires that are deliberately set when firefighters are in position to prevent them from spreading--to eliminate fuel for wildfires and to research the effect of fires in dieback zones. They will look particularly at the fires’ maximum temperatures, he said.
One such experiment, dubbed “Project Eagle,” involves burning about 200 acres near Eagle Springs in Topanga Canyon State Park, at the head of Santa Ynez Canyon. The area is an example of heavy dieback and is surrounded by roads and fire roads to contain the blaze.
“We’re looking at sometime in the week of the 24th,” of this month, if the weather is favorable, Franklin said. About 100 firefighters will take part, he said.