At Hart Prairie, trees removed to restore a landscape
Where there was once wide, open grassland now sits a forest of trees.
That’s not the way it used to be in Hart Prairie Meadow, outside Flagstaff. The trees wouldn’t have been able to survive if not for increased human settlement, land management and climate change. They have continued to encroach the region, altering the landscape.
So Coconino National Forest, in partnership with the National Forest Foundation, has begun restoration efforts in the meadow to help restore the habitat to a more natural state.
“What we have observed over the last 100-plus years is trees that historically did not exist in the meadow now are popping up,” said Andrew Stevenson, the project manager of the restoration project and Flagstaff’s district silviculturist.
“What we hope to achieve by moving out these trees is to restore the lowest grassy areas,” said Stevenson.
The project will treat approximately 241 acres, at a cost of about $157,000. That includes removing the trees by hand and chopping them up, which will help restore the meadow habitat, increase stream flows, improve watershed conditions and help maintain the rare and native Bebb’s willow and aspen habitats.
“This isn’t the type of project that appropriate dollars would normally go to because it’s not selling wood,” Stevenson said. “It’s not something that we have to do as a legal obligation.”
He said the project has been in discussion with land managers, researchers and community members for a long time.
The Hart Prairie restoration efforts began the last week of May and will continue through the end of the summer. It is projected to be finished by mid-fall, according to Stevenson.
Margaret Moore, a professor at Northern Arizona University’s Forestry Department, has focused a lot of her research on the Hart Prairie Meadow and the surrounding regions for the last 30 years.
Some of her research pushed the Hart Prairie restoration project forward.
In the mid and late 1800s to the early 1900s, she said, several things were happening in the region that affected the meadow today.
“It was like a perfect storm,” she said. “It was Euro-American settlement in the area. This is a pretty common story throughout the Western United States.”
Moore said the settlers came on to land that wasn’t theirs and took resources. European settlers brought livestock, both sheep and cattle. For 20 years or so, livestock increased when there was favorable moisture.
In the early 1920s, grazing was clearing out the grasses and making space for woody plants like Ponderosa pine, the native trees encroaching and taking up much of the former open space at Hart Prairie, Moore said.
“Basically you had livestock overgrazing these areas,” she said. “Almost simultaneously with that comes people putting out fires.”
The growing number of people put natural fires out more regularly.
“Fires are another thing that kept the density of the Ponderosa pine and Pinon-juniper woodland (trees) down.”
Moore said grass keep trees from getting a foothold in the soil. The tree seedlings have a hard time competing with grasses for moisture. But as the grass decreased, more space opened for tree seedlings.
“So a lot of the trees that are encroaching in Hart Prairie are 80 or 90 years old,” Moore said. Throughout the 1900s, good seed years would cause more and more trees to grow in waves. “Then they started to infill,” she said. With more trees and less grass, the feed for animals like elk, deer and antelope also decreased. So did wildflowers, which serve as pollinators. That also affected spring water.
“When you get more trees, you get more capture of the snow and so forth,” she said. “So you don’t get water that goes down into the soil and then eventually expresses itself in the streams.”
Moore said with more trees, less moisture percolated into the soil. With less moisture in the soil, there was less water to feed springs.
“Springs feed streams,” she said “That is part of the story with the Bebb Willows.”
Bebb’s Willow is a species indigenous to Canada and the northern United States. Hart Prairie holds one of its largest stands in the world, with more than a thousand trees in the meadow.
Abraham Springer, an NAU professor, has researched the water systems in Hart Prairie.
“The hydrologic implications of the dense forest are that the tree covers both intercept moisture, mostly from snow, and they transpire and evaporate most of that water back into the atmosphere,” he said.
Springer said he and other researchers have set up long-term projects to moderate the effects of tree density to the spring water.
While those studies are still in progress, Springer said one thing researchers have noticed is that Bebb’s Willows in Hart Prairie tend to be older.
“The question is why there is not a healthy distribution of age classes of the willow tree in Hart Prairie,” Springer said. “My group and others have spent the last 25 years studying that question.”
Springer said the current hypothesis is that there isn’t sufficient water to recruit new willow seedlings.
While Moore acknowledges that people don’t want to see trees cut down, removing some of them will help the natural environment overall.
“A 100-year-old tree seems really old, but this isn’t true of nature,” she said.
Moore said by taking out some of the trees, grasses and grasslands will benefit, which helps wildlife that are grassland dependent. She said fewer trees will also favor hydrology and get more water into the system, which will then help vulnerable trees like aspen and Bebb’s Willow.
The resulting landscape diversity is important to people so they can see open meadows, aspen, antelope and elk, she said.
“These parks and meadows are becoming rare landscape elements,” she said.
The National Forest Foundation is funding the Hart Prairie Meadow restoration with a contribution of $157,000.
“We’re working with counties, cities, states and really trying to pull the financial resources to meet a lot of critical needs that may not otherwise be met,” said Mark Brehl, National Forest Foundation’s Arizona program adviser.
The foundation is a congressionally chartered nonprofit organization. They receive a small amount of funding from the federal government that it uses as seed money to leverage additional funding from various sources, corporate sponsorships, grants and philanthropic donations, Brehl said.
He said the nonprofit’s focus is on both responsible and enhanced recreation, as well as forest restoration and conservation.
The Hart Prairie Project falls under the foundation’s “Northern Arizona Forest Fund.”
The area is deemed by the foundation’s board of directors as one of Arizona’s treasured landscapes.
“It encompasses the Verde and Salt River watersheds,” he said. Watersheds are areas of land where precipitation collects and drains off into a common outlet, such as into a river, in this case.
While the current work will treat approximately 241 acres of the land, Brehl said the whole project is much larger.
“The meadow restoration is just a component of this larger project,” he said.
He estimates the project to cover around 14,000 acres total. The efforts will include forest restoration, wildlife protection, maintaining a forest canopy, removing evergreens from aspen stands, doing some aspen regeneration, among others.
The Hart Prairie restoration project was on hold due to fire restriction measures, where logging equipment and chainsaws are prohibited from operating during the day. Brehl estimates it will pick up again in mid- or late-July when monsoon storms bring more moisture.
Moore, the NAU researcher, said if the trees are cut before the tree crowns and completely infills, there is hope of regaining grassland.
“The hope is that it brings more of a balance of former grasses,” she said.
She has seen ecological restoration research expand in the last several years and has seen improvements when it comes to ecological restoration.
“It’s a land ethic and a healthier attitude toward the land where you’re not just trying to extract resources.”