This past winter, the Bureau of Land Management (BLM) began preparing two Environmental Impact Statements to review the environmental of consequences creating a region-wide series of “fuel breaks” that will add thousands of miles of new linear non-sagebrush habitat across the Great Basin portion of Nevada, Idaho, Oregon and Utah.
The goal of fuel breaks is to reduce large wildfires in sagebrush habitat. Under natural conditions, sagebrush burns at 50-400 year intervals depending on the sagebrush type. However, the frequency of fires has increased, and the interval between wildfires has shortened. Wildfires are now one of the threats to the sagebrush ecosystem and dependent species like sage grouse.
Unfortunately, the creation of a massive network of linear pathways in the sagebrush steppe likely will not preclude large fires and will have serious impacts on sagebrush ecosystems.
Furthermore, this immense habitat degradation process is being done without any evidence that it is effective. Indeed, the BLM has admitted as much in a recent report where it concluded; “Despite the extensive use of fuel breaks in sagebrush landscapes, especially since the 1990s, the IRFMS-ASP points out that “no specific research within the sagebrush ecosystem has been conducted to evaluate their effectiveness”.
And like so many issues on public lands, one of the causes of large wildfires has to do with two factors that are off-limits for the BLM to consider.
One is climate change which the Trump administration denies is real. Yet there is abundant evidence that large wildfires are a direct consequence of warm, dry conditions.
The second factor leading to greater wildfire occurrence is livestock grazing. It’ s a bit nuanced, but livestock grazing facilitates the expansion of flammable exotic grasses like cheatgrass. Livestock enhances cheatgrass germination and survival by destroying biocrusts that cover undisturbed soils and alternatively weakening native bunchgrasses by chomping away at them, weakening their ability to compete against exotics like cheatgrass.
Because the BLM is prohibited from discussing the proximate factors contributing to larger wildfires, they are instead proposing measures to deal with the wildfires that are inevitable. This is somewhat analogous to medical doctors recommending radiation to treat a chain smoker’s lung cancer and never doing anything about the source of the cancer-cigarette smoking.
So, the BLM is stuck dealing with the symptoms of livestock grazing and climate change, rather than doing anything about these factors. I can predict that the proposal to build a series of fuel breaks throughout the Great Basin will ultimately fail to protect the sagebrush ecosystem and the many plants and animals that depend upon it, including sage grouse.
There are three major proposals for fuel breaks. One is to plant a strip of vegetation resistant to wildfire along roads. The most common species are either crested wheatgrass or kochia, both are non-native exotic plants from Asia. Unfortunately, over time, kochia and crested wheatgrass tend to spread into adjacent grasslands, thus directly competing with native bunchgrasses. Neither is particularly good forage for wildlife. Kochia tends to create sterile vegetation types with an understory of thorny bur-buttercup.
The second method is to bulldoze and herbicide a strip of land on either side of a road to kill all vegetation. This disturbance of soils enhances the spread of cheatgrass, so in effect, just creates a more burnable buffer zone. The elimination of native vegetation and the disturbance created by fuel breaks tend to enhance the spread of exotic weeds. One study in California found a 40% increase in exotic annuals along fuel breaks.
The third method discussed is targeted grazing. Targeted grazing is unlikely to be used widely in part because most ranchers are not interested in hauling their livestock out to graze a narrow strip of land and having to deal with keeping their animals confined to the targeted area. Not to mention that another obvious issue is that livestock enhances the spread of flammable cheat grass.
Another unmentioned issue with all of these fuel break strips is that ORVs like to ride them, and in the process disturb the soil and spread the seeds of weeds.
One problem with these “solutions” is that all large wildfires burn under what are termed “extreme fire weather conditions” which are characterized by high winds. With high winds, wildfires regularly jump 16 lane interstates or large rivers like the Columbia, so a narrow fuel break is not going to halt the advance of fires under extreme fire weather conditions. Wind easily throws embers as much as several miles ahead of a fire front, and the idea that fuel breaks a couple hundred feet wide will preclude fire spread under such conditions is delusional. Plus, it is suicidal for firefighters to be anywhere near a blaze occurring under such conditions.
In fact, a recent Dept of Interior report on fuel breaks admits as much concluding that “fire managers acknowledge that, under extreme fire weather conditions, fuel breaks are unlikely to adequately reduce fireline intensity, flame length, or rate of spread (Moriarty and others, 2016).”
Besides the fact that fuel breaks are unlikely to be successful in halting wind-driven blazes, there are many, many unintended negative consequences of such a proposal. Many wildlife species are impacted by such linear patterns with significant “edge effect” which result in habitat fragmentation.
For instance, snakes, frogs, amphibians, small mammals, and other wildlife are more vulnerable to predators in these open pathways. Indeed, there is evidence that coyotes, badgers, ravens, and other birds of prey regularly patrol linear fuel breaks and roads for that reason. And ground-nesting songbirds suffer greater egg predation from mice that are favored by linear travel pathways created by fuel breaks.
Some wildlife, including sage grouse, avoid such linear lines of open terrain. One study documented a “functional” habitat loss for sage grouse up to a mile from the linear vegetation break. Therefore, a massive network of linear shrubbery removal programs can significantly reduce the habitat for these birds.
Linear features like powerlines, pipeline corridors and so forth have been shown to reduce nesting songbirds, and the smaller habitat patches of sagebrush are avoided by such species as pygmy rabbits which have been petitioned for endangered species status. Plus, smaller sagebrush habitat patches are avoided by sage grouse.
So in the end, the sagebrush ecosystem and its associated wildlife will suffer significant ecological impoverishment as a result of fuel break creation, while at the same time, the effectiveness of fuel breaks in stopping wildfires burning under extreme fire weather conditions is acknowledged to be ineffective.
Worse for the American public is that the BLM and the current administration are refusing to deal with the two major causes of larger wildfires in the sagebrush ecosystem, namely domestic livestock grazing and climate change. Without acknowledging these factors and dealing with them, any proposals for fuel breaks will invariability fail.