The blaze could destroy some 2.1 billion metric tons of trees and plants, according to computer models that monitor short-term and long-term weather patterns and predict the growth of vegetation in the national forests.
Mark Rey, the Agriculture Department undersecretary in charge of the Forest Service, told the House Agriculture Committee on Wednesday that the country is in the midst of a dry cycle after several decades of wetter-than-normal conditions through the 1970s. The dry cycle is expected to last for several more decades.
Coupled with aggressive firefighting efforts that have kept forests from burning naturally and predicted a warming trend that spurs growth of vegetation, wildfires are expected to be more severe in the coming decades.
``We're going to experience some significant fire years for the foreseeable future,'' Rey said, adding that the predicted fire around 2035 ``is going to be a real corker.''
Under an alternate forecast, which assumes temperatures will warm more slowly, fire activity would increase more gradually.
Data on how much vegetation was destroyed in the 2000 and 2002 fire seasons, which were among the worst on record, was not included in the report.
In 1988, roughly 1.7 billion tons of vegetation were destroyed as blazes tore through thick stands of tall trees in Yellowstone and elsewhere _ the most destructive year since 1895, the first year for which information was available. Nearly 7.4 million acres burned in 1988.
James Hull, a state forester from Texas, said the data tracks what scientists in his state concluded when they began looking at broad historical data to figure out why fires there were burning so intensely.
The Forest Service's computer models were put together by agency scientists based in Corvallis, Ore.
Rey used the figures to again make the Bush administration's case that more needs to be done to treat forests to reduce fire risks _ either by cutting trees out of overgrown or insect-infested forests, or using fire under controlled conditions to burn out excess vegetation.
Also Wednesday, Rey said the Forest Service was re-establishing rules that allowed small areas of burned, dead or insect-infested trees to be logged without lengthy environmental reviews.
Similar rules were blocked by a federal judge in Indiana four years ago. Rey said the new guidelines, which will be published next week, meet the judge's concerns while allowing needed work to go forward quickly.
The administration is backing legislation that has already been passed by the House and is awaiting action in the Senate.
The Senate Agriculture Committee planned to vote Thursday on whether to send the bill to the full Senate for action, but Democrats and Republicans agree the bill lacks the 60 votes that would be needed to pass it over objections from the Democrats.
The bill would exempt 20 million acres of forests at most dire risk of fire from normal environmental reviews and would limit administrative appeals and seek to expedite court challenges on those tracts. The administration argues the appeals and court battles have caused long delays in the forest treatment projects.
The administration put in place new rules in May that allow logging on up to 1,000 acres and controlled burns on up to 4,500 acres in at-risk areas without environmental reviews and administrative appeals.
