Wildfire watch.

Authorities pinpoint certain western forests so stressed and vulnerable that catastrophic fires threaten this summer.

With over 10 million acres of forest showing serious stress in the West, wildfire is an enormous concern everywhere. That concern heightens during hot, dry summers. Actual events cannot, of course, be predicted. They are shaped by random factors such as weather conditions, lightning strikes, accidents, human carelessness, or lawlessness. What can be identified, however, are areas where forest health conditions are such that any wildfire is likely to become a major catastrophe.

AMERICAN FORESTS, in cooperation with forestry agencies and experts across the country, has identified some of the most serious problem areas at this time. These are forests that contain major areas with unusually heavy loads of dead fuels and dying trees.

In addition to demanding extra vigilance by fire-suppression agencies, these unhealthy forests cry out for preventive treatment. Careful salvage logging, thinning, fuel treatment, and prescribed fire is the first step toward ecosystem management in most places. Building a more diverse mosaic of forest types, conditions, and ages protects biodiversity, helps wildfire outbreak to be more "spotty," less intense, and less likely to damage watersheds. Investments in treatments to improve forest health will produce enormous financial savings to the nation, as well as the affected regions.

THE HOTSPOTS

Alaska: Entire watersheds are at extreme risk in Alaska, where over three million acres of spruce forests have been killed by spruce budworm in the last

five years. When these areas burn, fish and wildlife impacts will be felt over entire watersheds, and some of those impacts may last for decades.

Arizona: Spruce-budworm and bark-beetle attacks affect 200,000 to 300,000 acres of mixed conifer forests in the high-elevation San Francisco peaks. Intense fir encroachment is overtaking meadows, which decreases productivity of the herbaceous understory, which in turn affects the prairie-based food chain and, ultimately, big-game populations.

California: The Modoc National Forest in the northeastern corner has large areas of white fir that have invaded lower-elevation sites due to fire suppression since settlement. These are under severe stress, with insects killing virtually all the trees in heavily infested areas. Aggressive salvage is underway, but high-remain.

Idaho: Conditions are most serious on the Boise and Payette national forests. Insect and disease outbreaks over large areas, high fuel loads, and dry, moisture-deficient foliage on live plants contribute to high wildfire risk. Small communities, recreational homes, and valley farms and ranches are at risk as well.

Nevada: The Tahoe Basin in Nevada and California, is one of the most high-risk regions in America. Recent surveys have identified watersheds near Lake Tahoe where 85 percent of the trees are dead. Dense fir forests, the legacy of the pioneer logging era of the mid-1800s, are involved. Adding to the risk are the enormous number of high-value homes scattered throughout the forests.

Oregon: The Blue Mountains in northeastern Oregon have been experiencing a forest health crisis for a decade. A report issued by the four national forests involved estimates that half of the area is so far outside "ecological balance" that emergency treatment is needed. Wildfires have been avoided in recent years by a combination of favorable weather, good luck, and aggressive suppression efforts, but risks remain extreme.

Washington: The Colville, Wenatchee, and Okanogan national forests in the northeast all have areas of serious stress. Widespread spruce-budworm and bark-beetle infestations affect both federal and non-federal forests. The species shift from pines toward firs, largely the result of fire suppression since settlement, has affected nutrient and biomass cycling, increased wildfire intensity, and damaged soils and watersheds, according to Forest Service assessments.

Neil Sampson is the executive vice president of AMERICAN FORESTS.