“The closer we look, the clearer it’s becoming that wildfire — which long has exerted an enormous impact on western lands — is becoming a much bigger force than ever before.”
Above is the opening observation of an interesting new book that gives perspective on last month’s fires in Northern California and the puzzlement I described in a September post about the smoke I had seen in my native Pacific Northwest.
People who live and work near the western forests are well aware that there have been more fires, and more really big fires, in recent years. For the rest of us, author Gary Ferguson, a Montanan, provides a thoughtful, well-written study of the phenomenon in a handsome book full of great illustrations.
The story starts in 1905, when Theodore Roosevelt established national forests by executive order and the US Forest Service to manage those properties.
In those days, forests were national treasures, and the plan for dealing with fires was to Put Them Out. Over time, foresters learned that fire had its purposes, including clearing dead vegetation and allowing for forest regeneration.
Before people came along, fires were set by lightning. But today, most fires are caused by unintended human action — power tools, dropped cigarettes, contained burns swept along by wind — and a few by arson. In fact, more Americans than ever live near western forests in what is called the Wildland-Urban Interface (WUI) of small-density housing developments that make forest management, and fire management, more challenging.
Climate change factors include rising temperatures and variations in rainfall and snow accumulations. These have led to shorter winters, longer burning seasons and more really big fires, which Ferguson describes generally as ones that consume 100,000 acres or more. He emphasizes his point when he notes that fire containment costs rose from $600 million in 1995 to $3 billion in 2015.
Other associated costs are replacement of structures, lost timber, reduced water storage and electrical grid repair. And then there is the accumulating damage to forests, from which we derive half our water and whose trees absorb a significant amount of carbon dioxide.
By way of example, the author discusses the healthy regeneration of a lodgepole pine forest in Yellowstone National Park following a big 1988 fire, and then a different case in Colorado, where a 2001 fire destroyed a Ponderosa pine forest that had not even begun to recover 14 years later. The book includes photographs and information about other major fires from across the region.
Two essential points are that many factors are at work and that much research is being done. Ferguson discusses what has been learned from tree rings, satellite photographs, patterns of pine bark beetle infestations, the movement of fire based on wind and leaf observations, the changing composition of post-fire understory and the vulnerability of dry and dead trees following years of drought. The more that is learned, the more the process of fire management seems to become one of micromanagement.
But there is always more to know. The author quotes plant ecologist Frank Egler, who said this in the 1980s: “Ecosystems are not only more complex than we think. They are more complex than we can think.”