DWR mulching thousands of trees to ensure sustainability of native flora, fauna


ST. GEORGE — The Utah Division of Wildlife Resources is working on several projects that involve the breaking down of thousands of trees to make way for vegetation that sustains native animal species and conserves water and soil.

Armed with seven Bull Hog machines, project manager Curtis Roundy told St. George News contractors are taking down thousands of trees on over 1,600 acres of land north of Cedar City. Machines kicked into gear the week before Christmas in an isolated part of Iron County to begin the process of clearing trees from DWR, Bureau of Land Management and private lands.

Together, the seven Bull Hog machines clear about 60 acres each day. The project costs over $877,000, with a majority of the funds going toward the mastication contract of over $743,000.

Using Bull Hogs to mulch trees is the most popular method that the BLM and DWR use to practice forest mastication, with chaining and the Dixie Harold Method rounding out the top three. While chaining involves dragging a more than 20,000-pound chain between two bulldozers to tear trees out of the ground, the Dixie Harold Method uses a tractor to drag an up to 50-foot-wide frame with large teeth to churn soil and uproot vegetation.

Project process

The project consists of breaking down a large number of the trees standing southeast of Enoch, turning the plants into a mulch-like material spread over the land to help the ground retain moisture and hold together the fertile topsoil while feeding temporarily displaced animals.

Bull Hog machines continue the mastication of trees on Utah Division of Wildlife Resources, Bureau of Land Management and private land, Iron County, Utah, Jan. 8, 2020 | Photo by Ryann Richardson, St. George / Cedar City News

Afterward, a specially-designed blend of seeds will be littered over the fields using aircraft. The seeds are comprised of native, palatable plants for deer, elk and turkeys, which are the three main species that benefit from the area’s treatment.

Specifically, the seeds that restore the sagebrush steppe landscape, which is a grass, forb and browse plant community, including a variety of five grasses, 10 forbs, and browse plants such as sagebrush, bitter brush and cliffrose.

The mulch that is leftover from the removal of the trees will also provide cover to the new plants while acting as a seedbed for the desirable vegetation. In a couple of years, all that will remain of the mulch will be a dark, rich soil and a handful of trunks, Roundy said.

Pockets of trees will be left untouched in order to not disturb any possible archaeological discoveries waiting in the area. The trees will also be cut in a mosaic pattern to mimic natural vegetation.

“I guess this is sort of the ugly duckling phase, if you will,” he said. “It goes from what looks like a woodland forest to nasty mulch-looking stuff all over on the ground, but you come back here a year to two years later, depending on what the winter and the spring rains do, and this will be a wildflower patch.”

Contractors have a total of 78 days — weather permitting — to clear all of the necessary trees from the area before seeding can begin. Roundy said he expects the project to be completed in early March, although it will take about a year to see new plant life.

Wildlands attorney Kya Marienfeld with the Southern Utah Wilderness Alliance told St. George News forest mastication is far from the best practice. The Southern Utah Wilderness Alliance has filed several appeals to the Interior Board of Land Appeals after federal approvals to conduct “vegetation destruction projects” across the southwest, more recently in Grand Staircase-Escalante National Monument.

Treatments similar to the ones being conducted by the DWR in southwest Utah have one in three odds of improving foraging. And in sagebrush ecosystems, almost 66% of vegetation treatments meant to produce better forage for big game and cattle yielded negative or non-significant results.

Marienfeld said organizations initially advertised the practice as a way to greatly benefit grazing animals such as cattle and sheep. As time has progressed, although the treatment has remained the same, the justification has evolved.

“It’s harder for the state or BLM and other public land managers to say we’re going to go in and clearcut on behalf of cows,” she said. “Now, there’s a whole host of other reasons why these projects are justified. At the end of the day, they still benefit cows at the detriment of everything else.”

Fire suppression

This project is necessary due to the area’s fire-suppression efforts. Ordinarily, naturally occurring fires would periodically clear out and thin the density of the trees in the area. But due to the proximity of nearby homes, the height of the average tree and how densely packed the forests have become, regional officials have worked tirelessly to ensure fires can be prevented and easily extinguished.

Bull Hog machines continue the mastication of trees on Utah Division of Wildlife Resources, Bureau of Land Management and private land, Iron County, Utah, Jan. 8, 2020 | Photo by Ryann Richardson, St. George / Cedar City News

Although the downed trees and debris can become a fire hazard during the first summer, the debris is more likely to smolder and have short flames in comparison to the 15-foot trees that currently exist.

“We’re basically doing something right now that would have naturally occurred by fire, but we can’t really do that safely anymore in any other way besides tree mastication using machinery,” he said. “We can be selective.”

However, Marienfeld argues that science does not support the idea that these treatments prevent large-scale wild fires in pinyon- juniper woodlands. According to studies, biomass production is not the leading cause of wild fires, she said.

Changes in the climate, such as the prolonged warm and dry season Southwest Utah experienced last summer, is the leading cause of fires in forests. In some instances, using machines to remove vegetation, like pinyon and juniper trees, may benefit invasive species and increase fire danger, Marienfeld said.

“No one is arguing that we don’t have significant fire issues throughout the west,” she said. “We’re never going to push back on any sort of creating some sort of defensible space around communities when it comes to fire prevention.”

Restoring historic landscapes

The area being cleared has historically been a sagebrush steppe landscape.  However, in recent years it has become overcome with juniper pine and pinyon trees that threaten to completely overwhelm the sagebrush and force out animals, like the mule deer, who are dependent on it for survival.

The trees, mostly juniper pine and pinyon, steal the nutrients from the soil, keeping other species of flora from growing. The pine needles from juniper trees, he said, also release chemicals into the ground that prevent other plants from growing, which can cause top soil erosion over time as grasses, brush and wildflowers are stifled.

Despite this, the only plants that will grow under these trees are highly invasive, he said, including cheatgrass and mustard grass.

“What we’re doing is we’re coming back in and seeding the plants that should be here on the landscape and removing the trees, so the competition for nutrients and all the available things in the soil are available to the seeds that we’re planting,” Roundy said.

Marienfeld said forest mastication using Bull Hogs rarely, if ever, decreases runoff and erosion. Mechanical treatment disturb soils and often leads to increased rates of erosion, she said. The impact of the machinery on the soil is often increased in places that rely on soil crusts to sustain soil stability, such as in sagebrush ecosystems.

Benefiting native animal species

Animals are temporarily displaced during the process, but ultimately benefit from the demolition. Almost immediately, deer flock to the debris to enjoy juniper berries and other, more accessible treats that have made their way from tree tops to the bottom of the valley floor.

Bull Hog machines continue the mastication of trees on Utah Division of Wildlife Resources, Bureau of Land Management and private land, Iron County, Utah, Jan. 8, 2020 | Photo by Ryann Richardson, St. George / Cedar City News

Animals like the deer — including elk — will take advantage of the debris for months, Roundy said, following the Bull Hogs from area to area as the machines work to tear down trees.

Native bird species that regularly nest in the affected trees — like pinyon jays — have already traveled south for the winter, he said, and rarely, if ever, nest in the same tree twice. Officials waited until the birds had migrated to begin the process, and the project is expected to be complete before the birds return in the spring.

“We try to avoid times that displace lots of animals,” Roundy said. “As soon as we grind this stuff up, they move in and use it more heavily than they did before we did the treatment.”

Despite the Division of Wildlife Resources’ assertion that forest mastication benefits animal species that are native to the area, Marienfeld said this isn’t always necessarily the case. In fact, she said, a majority of the time treatments like forest mastication have a negative or not at all significant impact to ungulates, small mammals, birds and invertebrates in the area.

Bird species that require pinyon-juniper habitats, such as the pinyon jay, were the one exception to the lack of significant impacts, however. Bird species were disproportionately negatively affected by vegetation removal and mastication treatments.

Marienfeld argued that state and federal organizations are gambling with public and private lands when they employ forest mastication treatments.

Opposing views

The BLM and DWR use millions of taxpayer dollars each year to continue a practice with no measurable criteria that indicates that the treatment was successful while several studies have been released condemning it, she said.

“There are millions of dollars spent on these treatments, which are very heavy-handed, every year,” she said. “For there to really be negative or non-significant results at all is pretty unacceptable. Think of another use of taxpayer money where that would be allowed.”

If treatments such as these are to continue, officials need to conduct extensive prior study as well as independent post-treatment research. Ensuring that there is enough funding to include research and monitoring protocols after the treatment is complete allows for teams to create a baseline for a successful treatment and evaluate the efficiency of the practice over time.

Bull Hog machines continue the mastication of trees on Utah Division of Wildlife Resources, Bureau of Land Management and private land, Iron County, Utah, Jan. 8, 2020 | Photo by Ryann Richardson, St. George / Cedar City News

More than ever, however, it is vital for land managers to define what constitutes success, Marienfeld said. Not only will the creation of a rubric for success help land managers determine potential meaningful improvements but it will also establish a sense of transparency with residents.

Far before contractors kick on the Bull Hog machinery, wildlife organizations should be looking for the least intensive treatments first and only resorting to surface-disturbing practices when absolutely necessary, Marienfeld said.

Using passive restoration techniques, such as closing areas to grazing livestock, could be a more beneficial substitute to forest mastication, Marienfeld said. Passive restoration techniques are more cost effective and cause the least amount of disturbance to target ecosystems but are rarely considered by land managers.

Roundy said the DWR has been participating in Bull Hog mastication every year for about 20 years. In 2018, there were 27 projects in Southern Utah, and currently Roundy is managing seven other Bull Hog projects of similar sizes.

Copyright St. George News, SaintGeorgeUtah.com LLC, 2020, all rights reserved.

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