The Idaho BLM is proposing to remove juniper from over 600,000 acres of land in the Owyhee River area of southern Idaho ostensibly to benefit nesting sage grouse. Sage grouse avoid treed areas, so the idea is to cut down juniper to increase sage grouse habitat quality.
While there is no doubt from the literature that juniper removal may improve sage-grouse habitat use and quality in some instances, the BLM’s approach to sage-grouse recovery is disingenuous for many reasons.
First, without getting too much into the weeds, the entire narrative about juniper “encroachment” or “invasion” as the BLM characterizes it may be based on flawed assumptions about juniper and sagebrush ecology.
While juniper has increased in density and in some cases expanded its area over the past 100 years, whether this is natural colonization or even recolonization after stand replacement blazes are being debated.
There are some scientists (mostly in range departments who are nothing more than taxpayer-supported livestock advocates) who believe juniper is invading because the frequent fires they postulate occurred every 20-30 years in sagebrush ecosystems would have killed juniper seedlings. According to their logic, fire suppression and livestock grazing have led to more juniper that was formerly restricted to specific rocky areas where fires did not burn.
This narrative fits well with the BLM’s argument that juniper expansion is unnatural and therefore should be controlled.
However, other scientists (not generally referred by the BLM of course) find that historic fire rotations in Wyoming big sagebrush were as long as 137-372 years and 137-217 years for mountain big sagebrush.
To quote just one study “Results also suggest that historical sagebrush landscapes would have fluctuated, because of infrequent episodes of large fires and long periods of recovery and maturity.”
If you assume much longer fire rotations for sagebrush ecosystems then fire would not have restricted juniper. Rather after a major fire, juniper would recolonize areas that it may have previously occupied.
Why is this important? Because juniper may not be “encroaching” so much as reoccupying habitat.
Another explanation that is also likely is that climate change is creating conditions that favor juniper expansion as well. Natural variation in climate led to ebbs and flows of plant communities over time.
If this is the case then juniper expansion is more natural than the result of human influence, and it’s more difficult to argue for juniper removal.
The BLM and range professors tend to ascribe to the “invasion” and “encroachment” theory because removal of juniper tends to benefit livestock and both the BLM and range professors know who they work for—and it’s not the general benefit of the public.
Putting this issue aside for the moment, whether natural or unnatural, there is evidence that juniper removal can potentially improve sage grouse habitat. But is juniper expansion or “encroachment” the biggest factor in the decline of sage grouse and does this mean that juniper removal is the best overall strategy for recovering sage grouse populations?
The answer to that question is unequivocal no.
The elephant in the room that the BLM does not want to address is livestock production. There are 143 grazing allotments within the Owyhee area proposed for juniper removal. By far and away, livestock has a much greater impact on sage grouse in all parts of their life cycle than juniper.
Removing juniper is like bandaging a person whose finger is cut and bleeding a bit while you ignore that they are in the middle of a heart attack.
Livestock impacts start with sage grouse nesting. When cattle remove grasses and other vegetation, it reduces the hiding cover for sage grouse nests, exposing the nesting bird and eggs to predators. Lack of cover can also expose eggs to greater cold and heat that can harm eggs. Although not usually a major effect, some trampling of nests and eggs does occur as well.
If the sage grouse hen and her eggs survive predators, the next phase of their lives requires foraging for insects and forbs in wet meadows and riparian areas. Livestock is the major factor in degrading wet meadows and riparian areas through trampling and consumption of vegetation. Thus cattle, by diminishing the total area of riparian habitat as well as reducing vegetation cover expose chicks to greater predation losses.
In addition, the forbs that are critical to growing chicks are also consumed by livestock, leaving behind less high-quality feed.
Next, after the chicks are old enough to fly, another major source of livestock-induced mortality is fencing. Sage grouse are poor fliers and collusion with fences has been known to kill as much as 30% of the bird’s population in some studies.
Fences also make ideal surveillance posts for avian predators like ravens and golden eagles, again leading to sage-grouse losses. Of course, the only reason we have miles and miles of fences on our public lands is to facilitate the private use of public grasses for the private profit of ranchers. No cows. No need for fences.
Recent studies have also shown that the presence of cattle leads to increasing numbers of ravens, a major predator on sage-grouse chicks. Ravens rely on dead cows and afterbirth to sustain their numbers allowing their populations to increase over natural conditions, with serious consequences for sage grouse populations.
Another impact of livestock production is the creation of watering troughs and ponds throughout the desert country. These water sources tend to be stagnant and exceptional breeding grounds for mosquitoes carrying West Nile Virus, which again has decimated some sage grouse populations. Without cows, no need for troughs or ponds.
An additional way that livestock production negatively impacts sage grouse is through habitat fragmentation because of hay production. Though sage grouse can fly long distance at times, they are reluctant to fly over hay pastures because to a sage grouse, there is no cover to hide from predators—i.e. sagebrush. With all the valley bottoms devoted to hay/alfalfa production, this has created barriers to sage-grouse—albeit more commonly on private lands than public lands.
A very big impact to sage grouse associated with livestock grazing is the expansion of cheatgrass, a highly flammable exotic annual grass. Though sage grouse ecosystems are adapted to periodic fires, typically hundreds of years apart, cheatgrass has led to a major change in fire frequency. Cheatgrass dominated sites can and often do burn as frequently as every few years, completely wiping out the chance for restoration of sagebrush.
Livestock is responsible for the spread of cheatgrass in three ways. First, since most livestock is moved from various winter ranges to summer/fall grazing areas, they can carry the seeds from one area to another in their fur, inoculating new areas with cheatgrass.
Second, cheatgrass establishment is favored by the cattle trampling of biocrusts. Biocrusts by creating a non-permeable surface on the soil naturally inhibit the survival of cheatgrass seeds.
Third, by consuming the more favored native plants over cheatgrass, livestock give the exotic cheatgrass a competitive advantage over the native plants.
Finally, cattle can also damage sagebrush, breaking and trampling the plants.
When you put all these cumulative impacts together, there is simply no way to avoid major impacts by livestock on sage-grouse populations, which is why sage grouse are declining everywhere, including many areas without any juniper “invasion” or “encroachment.”
But instead of closing grazing allotments to save sage grouse, the BLM avoids antagonizing the ranchers and focuses money and attention on other factors that have a far less important role in the sage grouse decline. Indeed, in its Final EIS, it specifically states that it will not analyze the role of livestock production on sage grouse. In the end, juniper removal is unlikely to reverse the on-going slide of sage grouse towards extinction.