Habitat Restoration or Destruction? Pinyon-Juniper Removal Under Scrutiny

Are pinyon pines and Utah juniper invasive species?  The Department of Interior is enthusiastically proposing to cut down  large swaths of pinyon-juniper woodland across the Great Basin Desert, although conservation group Basin and Range Watch is raising doubts about the scientific basis for such projects.  The ostensible purpose of removing the pinyon-juniper is to help the greater sage grouse and reduce fire risk, although it appears more likely that the deforestation is to benefit private livestock grazing operations.  Interior's claims that the projects are intended to support the sage grouse were further undermined after Interior opened up important grouse habitat elsewhere to oil and gas drilling earlier this year, even though experts say protecting remaining habitat is the most important step we can take toward saving it from decline.

Greater Sage Grouse.  Photo from Interior website.
Restoring historic sage grouse habitat to the native shrub and grasslands that the species needs to succesfully forage and breed is not easy and can require at least 20 years of effort to ensure the right mix of plant life takes root.  This is why experts say protecting remaining intact habitat from destruction is the most effective way to help recover the species. But in some cases Interior is introducing non-native plants in areas deforested of pinyon-juniper.

Restoring sage grouse habitat should also take into account whether the land ever historically supported sage grouse . Interior's plans to remove pinyon-juniper woodland in portions of Nevada will target areas that may not have ever supported sage grouse.  If the pinyon-juniper removal plans target areas that may not have previously supported grouse, and are not immediately followed up with the intensive habitat recovery process needed to get the land up to sage grouse standards, then what is the real purpose of some of these projects?

Case Study: Egan and Johnson Valleys, Great Basin Desert, Nevada

Interior this year solicited public comments on a plan to remove pinyon and juniper from nearly 57 square miles of the Egan and Johnson Valleys north of Ely, Nevada.  In this part of Nevada, sage brush, pinyon pines and Utah juniper fill the landscape in a mosaic interrupted only by small towns and farms.   In an environmental assessment published for this "restoration" project, the BLM asserts that pinyon pines and Utah juniper are increasing in density and encroaching on lands that once provided sage grouse habitat.  Greater sage grouse normally breed and nest in habitat dominated by sage and grasses.  But pinyon-juniper stands have always been a part of the region's mix of plant cover.

Pinyon-juniper woodland in the North Egan Mountains, Nevada.  Photo by Basin and Range Watch.

Areas targeted for pinyon-juniper removal.
Interior's environmental assessment does not make the case that stands of pinyon-juniper targeted for removal replaced grouse habitat.  Without this evidence, this could just be a habitat conversion project, not a restorationg project.  In fact, one study questions whether changes in the density of pinyon-juniper habitat is the process of this vegetation mix reclaiming areas lost to deforestation during Nevada's mining boom during the 19th century. Budding settlements took down pinyon-juniper for smelting, home heating and cooking, generating steam in mining machinery, fence posts, etc. (The Historical Stability of Nevada's Pinyon-Juniper Forests, Phytologia, December 2011)

Interior says that the project in Egan and Johnson Valley is to benefit sage grouse, but it plans to allow continued sheep and cattle grazing in the area.  Cattle grazing can result in the loss of plants needed by sage grouse, and has been known to aid pinyon-juniper encroachment in other regions.   If the intent of the Interior project is to restore sage grouse habitat, then why would Interior re-introduce a threat to the grouse and a potential cause of pinyon-juniper encroachment?  Interior's environmental assessment admits that it will improve "rangeland" conditions for domestic sheep and cattle grazing.

Interior also claims that the removal of pinyon-juniper will reduce the risk of wildland fire, but this seems to be a throwaway excuse.  The targeted stands of pinyon-juniper are far from populated areas.

Furthermore, a review of historical imagery in some of the areas targeted for removal of pinyon-juniper shows very little change in the overall mosaic of vegetation cover over the past 15 years. If pinyon-juniper is encroaching on sage grouse habitat, its is doing so very slowly. And if the rate of change is so slow, it seems that other human-caused factors are more significant contributors to the decline of sage grouse habitat and should be addressed before we deforest pinyon-juniper woodland.

You can see below two images from Google Earth of Unit 3 (one from 1999, and the other from 2015), where Interior proposes to use the "Ely Chain" to remove pinyon-juniper.

Google Earth image of Unit 3 from 1999.

Google Earth image of Unit 3 from 2015.  Other than having color imagery, any change in the overall mosaic of pinyon-juniper and sagebrush habitat is minimal.
  
Methods of Removal and Restoration Further Sow Doubt

If you planned to restore habitat for sage grouse would you disturb the soils, use heavy machinery to drag chains across the land, and then plant non-native grasses? That will not bring sage grouse back, but it is what Interior plans to do in the Egan and Johnson Valleys, according to its environmental assessment.

If you drag this chain across 15 square miles of intact pinyon-juniper woodland, do you suddenly create sage grouse habitat? No.  But you may get some cheap cattle grazing lands.

According to the environmental assessment for the Egan and Johnson Valleys project, over 15 square miles would be "chained," which involves one or more bulldozers dragging a heavy chain to rip down stands of multiple pinyon and juniper. This process would be extremely destructive to existing wildlife and the soils that Interior supposedly hopes will eventually sustain grouse habitat. Another several square miles would require heavy machinery to cut down pinyon and juniper, leading to additional erosion of soil quality.

Once Interior rips down the pinyon pines and juniper trees that it claims are encroaching on grouse habitat, it proposes to introduce non-native plants.  According to the environmental assessment, Interior will use non-native seeds in much of the area to grow grasses. Non-native seeds are unlikely to support quality sage grouse habitat. But they probably will support sheep and cattle grazing. The environmental assessment does not seem to propose anywhere near the intensive management regime required to truly restore sage grouse habitat, just as it does not even provide evidence that grouse ever used the lands in question. But we do know from the environmental assessment that two species will benefit from the project - domestic sheep and cattle.

Let's be clear. Plant species' ranges are always changing, and human actions can accelerate the introduction of non-native species or throw off a region's mix of plant life.  Getting rid of truly invasive plant species is a valid approach in many cases of wildlife habitat restoration.  But a clear case has not been made that pinyon pines and juniper trees in the Egan and Johnson Valleys are threatening sage grouse habitat.  If pinyon-juniper encroachment on key grouse habitat is identified, addressing the problem should be done so with careful study and long-term restoration in mind.  Fixes require a scalpel, not a sledgehammer.  Pinyon-juniper habitat is declining in other parts of the US.  And although it may not provide habitat for sage grouse, it is still a vibrant ecosystem.

Comments

Popular posts from this blog

Does The Military Really Need More Desert Bombing Ranges?

Air Force May Reduce Public Access in Nevada Wildlife Refuge