By Gary Fox
Millions of pines, cypress, juniper, spruce, piñon and firs have died all across Arizona and people are quick to point the finger at bark beetles as the culprit for killing these trees.

The spruce-fir forest of the Pinaleño Mountains near Safford have suffered severe tree mortality from bark beetle and defoliating insect attacks for the past several years. Bark beetle attacks have killed large numbers of trees in the spruce-fir forests of the San Francisco Peaks north of Flagstaff.

An estimated 100,000 piñon pines have died in the transition zone east of Flagstaff. Ponderosa pines are suffering severe attacks in the Flagstaff area. Some neighborhoods in and around the Flagstaff area have lost nearly 100 percent of their pines.

Tom DeGomez, an associate extension specialist in The University of Arizona School of Natural Resources, has been studying bark beetles for the past four years. Working out of the Southwest Forest Science Complex at Northern Arizona University in Flagstaff, he isn't so quick to blame the beetles as the only reason trees are dying.

"Bark beetles are not vicious killers," DeGomez said. "They are doing what comes naturally to them. Bark beetles have been around for eons. They are one of the natural checks and balances that are regulating forest density. Overly dense forests, drought conditions, dry sites, and rocky soil conditions all are contributing factors.

"In pre-settlement times in northern Arizona, Ponderosa pine stands had 20 to 40 trees per acre," DeGomez said. "Today, many areas of northern Arizona have 800 to 1,200 trees per acre.

"There is an estimated176 million ponderosa pine trees in the Coconino National Forest today," DeGomez said. "It was less than a tenth of that 150 years ago."