Year in Review: Beetles continued to kill trees during unprecedented epidemic
"It definitely slowed down, and we didn’t experience it like when it went crazy in 2002," said Ian Fox, a forester on the Prescott Forest.
Also on the positive side, it appears that the new areas the beetles are hitting are not dying off so much in huge swaths but in more of a scattered mosaic pattern.
"These beetles could really help us out on the forest health if it comes in more of a mosaic," by thinning out the overcrowded forests in a more palatable way, DeGomez said.
The beetle outbreak hit with a bang in 2002 after years of drought and wildfire suppression led to unnaturally overcrowded forests competing for less and less available moisture.
An especially dry spring in 2002 that produced little or no rain throughout northern Arizona was the final trigger.
While the beetles are ever present in the forest, taking out dead and weak trees, no one had ever seen such an outbreak in this region.
Before people even realized what was happening, trillions of beetles turned swaths of ponderosa pine forests brown.
Crown King, about 30 miles south of Prescott, was one of the hardest-hit areas; by the fall of 2002, about 90 percent of the ponderosa pine trees surrounding the tiny former mining community were dead. The Prescott Basin also experienced staggering numbers of dead trees, since like Crown King, its pine trees are among the lower elevations of the forests’ range.
U.S. Forest Service flights over the Prescott National Forest estimated that 400,000 trees on 75,000 acres had died by August 2002, and more than two million had died across Arizona over 500,000 acres of forestlands.
But Forest Service officials knew that number was low, since many of the dead trees weren’t showing telltale signs yet, said John Anhold, a regional entomologist with the Forest Service.
The Forest Service flew over Arizona’s forests again in August of this year, and have since repeated some flights and added others so they can gather more accurate numbers.
The agency probably won’t have a final report from the latest aerial surveys until February, but preliminary estimates calculate that 15.5 million pine trees on 660,000 acres are now dead in Arizona.
On the Prescott Forest, the pine mortality estimates have increased 10-fold to 4.1 million. But like elsewhere, the increase in acreage was less dramatic, from 75,000 acres to 93,000 acres.
The statistics indicate that the beetles, which can fly only a few miles, are in-filling areas where they already hit last year more than they are spreading to new areas.
The statistics also indicate that thousands of trees that were dead by August 2002 weren’t yet showing signs of it. Fox figures that most of the trees that turned brown after August 2002 died by November 2002.
The beetles moved to higher-elevation sites this year that had been more resistant to the outbreak, such as areas around Williams, just above the Mogollon Rim, and the north side of the Apache-Sitgreaves National Forest, Anhold said.
"Just out of sheer numbers, they’re able to overcome trees on better sites," Anhold said.
He told of one Forest Service summer tour with Northern Arizona University students through piñon forests where participants saw black clouds of beetles landing on people and flying into their mouths.
Putting the 2002 outbreak aside, this past year still would be among the worst outbreaks in history, Anhold said.
"Are we out of the woods with this outbreak? I don’t think so," Anhold said.
The Forest Service traditionally restricts its forest health flights to pine forests, but expanded the flights this fall to include more of Arizona’s piñon forests.
Those flights confirmed that the bark beetles that attack piñons are devastating those forests even worse than the pine forests, killing off 23 million piñons just in areas near pine forests.
On the Colorado Plateau, the piñon mortality is "phenomenal," DeGomez said. The piñons on the north side of the San Francisco Peaks look as bad as the pines around Crown King, he said.
Prescott National Forest officials are trying to conduct salvage sales in the dead pine areas in an effort to reduce wildfire danger that the standing dead trees exacerbate.
Forest employees and the county government also are cutting dead trees themselves near urban areas and roads, while a Prescott-area team overseen by local fire departments continues to help private property owners cut down all their dead trees.
Prescott Forest officials estimate that they have cut nearly 10,000 trees dead trees on 563 acres since the beetle epidemic took hold. Current projects are aimed at another 18,500 trees on 776 acres in areas on the west side of Prescott, plus around Lynx Lake east of Prescott, Senator Highway south of Prescott and Crown King.
The Forest Service plans to pay for satellite images to help plan which sites the agency needs to tackle around Prescott next.
The satellite images also will help with the analysis of the Boundary Project.
The 29,000-acre Boundary Project would be the largest vegetation-thinning project the Forest Service has ever undertaken on the Prescott National Forest, and one of the largest in the Southwest.
The Forest Service has been working here and there on the Boundary Project analysis for about three years now. Its goal is to thin out the forest surrounding Prescott to reduce the chances of a wildfire coming off the forest into town.
Earlier this year, District Ranger Ernie Del Rio withdrew his decision to move forward with the project, so officials could better analyze the cumulative impacts of the beetle epidemic and the Indian Fire of 2002.
Officials hope to issue a new decision by March and carry the project forward in 2004.
The 140,000 acres of pine forests on the Prescott Forest now have densities of 200 to 800 pine trees per acre compared to pre-settlement levels of 60 to 80 trees per acre, officials estimate. Many of those trees now are dead.
The same unhealthy forest conditions exist throughout Arizona, prompting the formation of a governor’s and legislative task forces to seek forest health improvements.
The Joint Legislative Task Force issued a list of recommendations Friday, including the formation of pilot programs and a letter to Congress supporting the speedy implementation of the Healthy Forest Initiative that the president signed earlier this month.