CHECKING OUT THE HOTTEST SPOTS FIRE OFFICIALS TEST VEGETATION TO HELP DETERMINE BLAZE RISKS.

Byline: Judy O'Rourke Special to the Daily News

SANTA CLARITA - Forest Service officials don't talk to plants, but plants talk to them - and they're saying the fire danger right now is high.

The dialogue is not of words, but of science.

To measure the moisture in the heavy brush that fills the Angeles National Forest, the experts take plant cuttings, weigh them, then dry them and check their moisture by the change in weight.

``It helps us be prepared,'' said Tracy McGuff, engine captain for the U.S. Forest Service station in Texas Canyon north of Saugus. ``A fire's going do what it's going to do, we can't change the way it's going to burn, but maybe we can order more (support crews) earlier.''

McGuff performs the test more often in summer and fall than in winter. The Forest Service does not bracket any period as a fire season because optimal fire conditions can spring up anytime. Today, green bushes are so dry they would burn like dead ones.

In past years, the agency has used the information drawn from samples of drying vegetation - forest-fire fuel - to close off parts of the forest because of the fire danger.

``You can instantly equate results of tests to what it means on the ground,'' McGuff said. ``You can link that in your mind to what kind of fire behavior you're going to see.''

Some areas in the Angeles have not burned for 50 or 60 years so the chaparral there is dense and the fire hazard mounting.

The Forest Service shares its moisture test results with the Los Angeles County Fire Department, data used along with wind, humidity and temperature in the department's daily fire weather forecast.

``We augment our staffing based on the information,'' said Jason Hurd, a fire department spokesman. The forecast can range from low to extreme. Friday the fire hazards were high to very high, normal for this time of year.

In the Santa Clarita Valley, more and more neighborhoods are backing up to forest lines, creating a problem for the Forest Service, said Cid Morgan, district ranger for the section of the Angeles that spreads around the Antelope and Santa Clarita valleys.

Residents are required to clear brush 100 feet around their homes to create fire breaks, but that might mean the clearance area intrudes into the forest, Morgan said.

Thus the efforts to prevent fires by sampling moisture in the brush year- round.

McGuff tests manzanita and chamise, snipping pieces a quarter-inch or less in diameter and weighs them. Then she cooks them for 12 to 24 hours in a convection oven heated to about 205 degrees to remove any moisture. The samples are weighed again and, using a complex math formula, she determines how much of the lost weight was from water.

Plants go through seasonal cycles, where they soak up water and grow, then are dormant. In the dormant phase plants stop absorbing water and become dry. When that dry fuel is dense, a forest fire burning 800 to 1,400 degrees can set massive acreage ablaze. By contrast, a high moisture level quells flames.

``It's like blow-drying your hair,'' McGuff said. ``If it's dripping wet, you have to blow-dry a long time. If it's been drying for a while on its own, you don't have to blow-dry as long. If hair is very thick it takes a long time to blow-dry.''

Dry brush along Interstate 5 and the Antelope Valley Freeway offers a vivid example of what happens when hungry flames are fanned. If a car catches fire on the freeway in February, there's less of a chance the flames would spread rapidly into the brush. Come September though, a car fire can set off a wildfire.

``The fuel is more dry and ready to ignite as soon as heat's applied to it.''

McGuff, who has sampled plants for a dozen or so years, said the drying cycle is lagging this year compared to last year.

However, Morgan noticed that brush fires erupting in the past couple of weeks are more difficult to suppress than they have been in months. The Forest Service has brought in extra hand crews as backup if their mobile hotshot crews are deployed elsewhere.

`'It's raising the hair on the back of our necks - like, here we go again,'' Morgan said.

Judy O'Rourke, [phone]

judy.orourke(at)dailynews.com

CAPTION(S):

3 photos

Photo:

(1 -- 2 -- color in AV edition only) Danny Brueklander of the Forest Service, above, takes samples of manzanita and chamise, right, in the Angeles National Forest to test moisture content and determine fire danger.

(3) Danny Brueklander of the Forest Service checks weather to help gauge fire danger in the Angeles National Forest.

David Crane/Staff Photographer