Rolling down the hills of northern Arizona, a sea of pinyon juniper trees steadily encroaches into the grasslands area. Nestled among them, a massive woodchipper kicks up dust into the dry air as a crew feeds it a steady stream of logs and branches. A thinning crew works hard to cut back the junipers to restore the grassland landscape and retain dwindling water resources. As crews remove these encroaching trees from the landscape, more water can stay in the soil.

This grassland restoration work is part of the Chino Landscape Restoration Project on the Prescott National Forest and is creating more opportunities for water and life to return to the landscape. Spaces are opening up for flowers to bloom, native pollinators to buzz, and pronghorn to migrate across the grassland with their young.

“Most people from this area understand that the juniper have increased beyond their natural density. Juniper is a very, very hardy native plant, but it is very invasive into grasslands if it's not managed properly,” said John Kava, a district ranger on the Prescott National Forest.

The need for fewer junipers and more water on the grassland brought together a range of partners, including ranchers, scientists, hunters, and a cement company.

Water for cows

“You don’t think about it until you turn the faucet and [water] doesn’t show up,” said Reuben Verner, a third-generation rancher. “And at some point, with the growth that we’re seeing, sooner or later we’re going to run out if we don’t start learning how to manage this as a renewable resource.”

Verner is a grazing permittee who moves his herd across the grassland on Forest Service grazing allotments that are also part of this restoration project. For Verner and his cows, water means survival. The importance of sustaining water resources was passed down through generations of raising cattle in the arid grasslands. 

Programs like this grassland restoration project will help Reuben Verner and his daughter, Mary, battle drought conditions and keep forage on the landscape. (Forest Service photos by Preston Keres)

Ranchers with long history and local knowledge of the landscape—like Verner—are critical partners to restoration and study of resources and landscapes like this. They are out on the ground daily and keep the Forest Service, its researchers, and partners updated on any changes on the landscape.

From the soil to the sky

Meanwhile, Forest Service scientists Jackson Leonard and Roger Tyler monitor moisture left behind in thinned juniper stands. Monitors located throughout the forest log the amount of moisture in the soil to verify whether the areas where juniper were removed retain more water.

“Our work based on satellite data provides estimates of juniper tree reduction for the Forest Service and, more specifically, for local ranchers—people like Ruben—who can now see the impact of the reduced juniper cover, especially on forage, specifically both for livestock and for wildlife that we're trying to improve the habitat for,” said Teki Sankey, University of Northern Arizona professor who is also conducting research on the site with Leonard and Tyler.

Every hour, the Forest Service scientists receive new data from18 soil moisture data loggers, set up across the restoration sites, that simultaneously send them their latest numbers tracking how much water is in the soil.

From above, daily satellite images show the thinning crew’s progress, visualizing where each tree is cut or left behind. On the ground, sensors and maps measure evapotranspiration, or the amount of water moving between the plants and soil into the air.

“What our work here shows is that both thinning and mulching conserves soil water,” said Sankey. “We are also demonstrating the utility of a lot of these new satellite data in a session with a lot of in-situ ground-based measurements.”

With this data, scientists are showing that fewer juniper trees on the grassland landscape means more water retention in the ground. That means more water for forage growth, livestock, and wildlife such as pronghorn.

Reopening the migratory corridor

An important pronghorn migration corridor flows across the grasslands on Prescott National Forest. Able to run in ultrafast bursts, pronghorn prefer open grasslands with maximum visibility to bolt away from predators.

As juniper trees grow into the grasslands, pronghorn face greater risks moving through the dense trees that can hide predators such as coyotes and mountain lions. Unable to move safely through this landscape in recent decades, the pronghorn population has been in decline.

The original plan to thin junipers on the grassland was created by Arizona Game and Fish to restore the pronghorns’ route. As the partners work together to re-open the migration corridor, both wildlife viewers and hunters alike will have more opportunities to enjoy greater numbers of pronghorn thriving in these grasslands.

“One of the most amazing things is to see the animals move back in, to see the pronghorn moving back into the area as we're just finishing our work, so we know that what we're doing is improving the habitat. We know that what we're doing is improving the watershed,” said Matt Monahan, president of Reliance Brush Management Inc., which is contracted to thin the juniper trees.

A key player in this partnership, Matt Monahan, president of Reliance Brush Management, thins the juniper, which can absorb up to 30 gallons of water a day, and sends the biomass to the nearby cement plant. (Forest Service photos by Preston Keres)

While wildlife spread across the re-opened grassland, the journey isn’t over for the juniper trees that were taken out of their way. Monahan’s team turns the cut trees into woodchips for biofuel.

Cementing relationships

At Drake Cement, trucks full of chipped trees from the restoration site rumble into the plant. Each day, the cement plant uses tons of woodchip biomass, much of it sourced from the juniper trees felled on the grassland restoration project, to fire their kilns.  

It’s a creative solution that reuses wood byproducts while also supporting the economy.

“We create jobs for the local residents. Most of our employees live about 20 minutes from the cement plant in a small town,” said Desirea Haggard, the vice president of sustainability and environment for UNACEM North America.

(left) Jackson Leonard speaks with Desirea Haggard, the Vice President of Sustainability and Environment for UNACEM North America, in front of pile of biomass from the juniper trees. (Forest Service photo by Alexis Neukirch) (right) Desirea Haggard stands in the control room of the Drake Cement plant. (Forest Service photo by Nehalem Clark)

A win, win, win

While Forest Service employees, cement plant workers, heavy machinery operators, ranchers, and professors all have different needs and interests, they came together to support grassland restoration and multiply the benefits to their shared landscape and community.

It takes everyone coming together, and it takes time. But it’s worth it.

Learn more about this project and Jackson Leonard’s work on the Rocky Mountain Research Station website. Sign up for the Rocky Mountain Research Station email list to receive updates about more of the latest Forest Service Research.