It seems only a couple of years ago that while driving around the outskirts of Santa Fe, New Mexico, I was struck by the number of dead piñon pine trees scattered among the sparse, desert-hugging piñon-juniper forest. As I drove higher the forest became thicker and the pine mortality climbed, too. Clearly, among the tree population, a kind of genocide was in progress, for from all appearances their neighboring juniper (cedar) trees and other plants were in fine condition.
What was going on here? Were the pines dying for want of water? Well yes, but apparently no. The killer was large numbers of a small insect named Ips Confusus or, in my lingo, the piñon engraver beetle, so named because it engraves pathways into the wood under the pine bark.
Healthy piñons can protect themselves against Ips and other beetles, but those that have been weakened by lack of water have little defense. When one tree dies, the beetles move on to another; when one stand of piñons die, they move on to another stand; and so on. Lack of precipitation – my place has received exactly one quarter inch of snow so far in the first six months of 2013, something I blame on global warming – may not immediately kill the tree, though it is causing some mortality this year. But it does sap its strength and turns it into a more or less defenseless meal for piñon beetles. This year’s continuation of drought threatens a resurgence of the beetle attack that began to abate after 2005, and foresters noted the appearance of pine seedlings that mostly escape the beetles’ attention and survive relatively well in drought conditions.
The Nevada Forestry Commission tells us that bark beetles, in good times, are considered beneficial creatures, culling weak trees from a healthy forest so that the deadwood can offer nutrition to the forest floor and its animal inhabitants (which will also eat spare beetles). In bad times, of course, the picture is not so rosy. “The current drought status [in New Mexico] is triggering more bark beetle activity and tree mortality,” Daniel Ryerson of the US Forest Service told me. “Last year we saw an increase in piñon mortality (in addition to Ponderosa and mixed conifer), much from Piñon Ips, in the southern half of New Mexico. Given the continuing dry conditions we expect to see more activity this year and in some areas are seeing tree mortality directly from the lack of water.”
Beetle infestation is by no means restricted to trees in America’s Mountain West. “Until recently, the largest spruce beetle infestation in British Columbia was less than a square mile, Jeffrey Lockwood wrote in an excellent UU Observer article. “The current outbreak has killed more than 1,300 square miles of forest as part of an unfolding ecological conspiracy.”
“Across North America, bark beetles have infested 234,000 square miles of forest,” he continued, “or about 94 million square city blocks, forty-two Connecticuts, four New Yorks, or almost one Texas.”
It doesn’t stop with beetles. Regularly on the evening news we are reminded that the unusually dry weather that accompanies global warming more often unleashes a more familiar threat – forest fire. According to US Government figures fighting them costs about $9 million a day; on one single disastrous day, June 17, 2002, an estimated $9,403,000 was spent battling 196 wildland fires that scorched over 51,000 acres of land in parts of 11 states. Forest fires not only damage watersheds and private property; they also cause bronchial problems for residents of regions affected by smoke and haze.
Ips Confusus may have little to do with forest fires other than to provide deadwood fuel, but it is among many small creatures that, especially in drought, are killing more trees than nature intended, causing havoc in America’s forests. Another is homo sapiens – us. Lockwood warns that we have to get used to “being brutally honest with ourselves, changing our lives in ways that cause us to attend to, rather than acclimate to, our disturbing similarities to the voracious, unrepentant bark beetles.
“Even if all of the green technologies on the horizon come to fruition and are adopted worldwide, most of our environmental problems will continue unless there are fewer people,” he adds. “A world with a billion electric cars will require a whole lot of power plants, most of which will burn fossil fuels. By mid-century, the human population will approach 10 billion people. It’s simple math: We need fewer of us making winters warmer, beetles happier, and trees sicker.”
We also need to be safer and more conservation-minded stewards of the natural world. In my neck of the woods, Forest Service recreational areas are now closed because of fire risk. Everywhere, with the July 4 holiday almost upon us, we need to be extraordinarily careful in our use of fire.