First, a little regional context. Relative to other places I've worked, in much of California there is a fear of fire... in many ways, a legitimate fear. Here, where it doesn't rain at all for half the year, fire at the wrong time and place can be catastrophic to both human and natural features.
Particularly in Trinity County, which is a little inland and thus warmer and drier than the coastal counties, every summer is wildfire season. Weaverville has burned twice in its history, and the threat remains that it could happen again. There and in many smaller communities, residents wear masks for several days each summer as particulate matter and smoke from fires miles away descends on the town. Obviously, these folks pay attention to fire policy. And they vote.
The wildfires happen in part because of many decades of land management decisions, including fire suppression and a resulting tinderbox of brush and even-age stands of Douglas fir. In this context, returning fire to the land in a controlled manner seems to be smart policy. Properly implemented, it is.
The danger comes when land managers get overenthusiastic. The tendency is to want quick results. But 150 years of bad land management can't be fixed in three years. These things take time. Unfortunately, some land managers are trying to push prescribed fire into the late summer and early fall period, before the rains come, to get hotter fires and kill more trees. This is an accident waiting to happen, and it also betrays impatience and a misunderstanding of how natural systems function.
The diverse forests that early white settlers found in this region were burned often. The structure of those forests had resulted not from hot fires killing trees, in most cases; instead, they were the result of millennia of survival. Low ground fires killed most seedlings in most years, but usually some seedlings survived. The ones that survived long enough grew to a large enough size to be fire resistant. As old trees died and fell, some of these saplings grew into the canopy. Fire frequency and intensity drove survival rates and locations, in many places resulting in diverse multi-layered canopies, open grown structure, and the presence of a low herbaceous understory.
Local native elders have told me that, at least near the Humboldt-Trinity County line, their ancestors burned in the late fall, right after the first rains. Conditions would have been right for safe fires, easy to control, yet the ground would still be dry enough to carry the fire. I've watched lines of fire, flames only six inches tall, creep up wooded hillsides. Smoke and particulate matter from these low fires is minimal outside the immediate fire line.
The hot, intense fires that happen today during summer wildfires are very different. In even age stands, they can become devastating crown fires killing most trees and spewing huge amounts of particulates into the air. Even prescribed fires, if they're done too early and with the goal of killing some mature trees and shrubs, can have adverse air quality impacts far outside the region of the fire. Not only do these intense fires encourage a different kind of community structure... often the regrowth is a thicket of shrubs and saplings which is even more fire prone... but they can also jeopardize local support for fire management.
Thus, I counsel patience. If the goal is to knock back Douglas fir that are encroaching into oak woodland or grassland habitat, perhaps some of that work should be done mechanically. Cut small saplings, or girdle larger trees thus creating valuable standing dead snag habitat. Follow up with low intensity fires over time, later in the fall when air quality is better. Take a long term approach. Write management plans that look at spans of decades in detail, and consider the implications over centuries. Consider what will be there when todays forest is dead and gone, and saplings which have not yet sprouted have grown into the canopy.
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