Sagebrush examination determines fire risk

SHOSHONE - Something as simple as the amount of water in a sagebrush plant can influence spending by the Bureau of Land Management.

After collecting moisture and related data for decades, BLM fire specialists have learned which numbers mean increased fire risk and at what point they need to beef up their firefighting resources.

On Thursday, two BLM fuels crews competed in a "blitz" of nine measurement sites managed by the agency's Shoshone Field Office. Their bi-weekly mission is to collect 10 samples of sagebrush at each of the sites within one day and measure the plants moisture content.

Fuels experts Erik Valdez and Joanna Anderson collected sagebrush on BLM land south of Shoshone, one of their lower sites. Valdez explained how the nine sites vary in elevation and average rainfall, allowing managers to get a composite picture of fire risk across the valley.

After six years of sampling, Valdez knew enough to look at Thursday's sagebrush and estimate the moisture content at around 80 percent.

"That's pretty low," Valdez said. "Sagebrush can hold as much as 200 percent of its weight in moisture."

Valdez said sagebrush normally contains about 80 percent water in August, even in the dry year of 2007 when the Magic Valley suffered a rash of fires. The difference this year, he said, is that the moisture content stayed up around 180 percent before it began to dry out during the first part of July. In 2007, it dried out about a month earlier.

Comparing moisture levels with weather patterns, the desert's fuel load and other information allows the BLM to predict wildfire risk. Its rating differs from the one used for the colorful "Fire Danger" signs posted by the U.S. Forest Service along highways, Valdez said.

When the BLM's rating gets high, as it did in 2007, that's when officials know to request extra money from the state to help with fire suppression.

"Our numbers can mean the difference between the decision to let people take more days off or to request more people," Valdez said.

The specialists sample more than sagebrush at some sites. Utah juniper is collected at two sites where it's abundant near Burley, and grass loads are gathered at three sites to see how much fuel a potential fire would have. Loads include both living grass and last year's dead stalks.

Loads are low this year, Valdez said, because larger-than-normal numbers of voles have eaten much of the grass. Indirectly, the voles have been responsible for the lower fire risk, he said.

"The Starlight Fire was right in vole central, and that fire could have been a lot worse if there had been more grass," Valdez said.