What can be done to slow the spread of eastern redcedars in Western Oklahoma?
Eastern redcedars are spreading across Oklahoma and slurping up billions of gallons of water each day. New legislation at the Oklahoma Capitol aims to do something about that.
When Kelly Roberts was a kid in the 1970s, she and her family cut down an eastern redcedar every year to use as their Christmas tree. Fifty years ago, Roberts said the trees could be hard to find.
“I remember traipsing across the pasture and there were very few. So we would have to walk a while before we would find one and then rule it out or rule it in,” Roberts said. “Now I can drive down the highway and pick any one of the millions of cedars that are infested across our state.”
In 2017, researchers estimated that the state was home to about 462 million eastern redcedars. And that number is always growing—every year, eastern redcedars take over another 300,000 acres of Oklahoma land, according to some estimates.
“I think one of the problems with this issue is people don't understand just how big it is,” said Roberts, who now advocates for eastern redcedar management in her free time.
Chris Zou is an ecologist at Oklahoma State University, where he’s studied woody species like eastern redcedars for decades. He says they aren’t any thirstier than other trees—on average, each tree uses a little more than 6 gallons of water each day. In fact, they can survive in drought-stricken areas without much water at all.
But that’s part of the problem—they’re using water resources where they’re most limited, like in western Oklahoma. Jimmy Emmons farms in Dewey and Roger Mills counties, where he says water availability has dwindled.
“These springs hadn't ran in the past 20 years and everybody thought it was drought,” Emmons said. “In 2018, we had an extreme wildfire that consumed 360,000 acres, I believe. Immediately we started seeing the streamflow. Ponds filled back up, springs started running. It was the cedars that were gobbling up the water.”
Zou warned that removing the trees doesn’t always produce such dramatic results.
“If you wanted to cut a tree and get water from a stream, that may not happen,” he said. “But that does not mean that's a waste of your effort. Because remember the cost of doing nothing.”
Eastern redcedar encroachment isn’t only a rural issue. Zou’s research has predicted that if the grasslands around the North Canadian River fully convert to redcedar woodlands, the trees will drink up more water each year than Oklahoma City uses.
“If you look at the past history of the exponential growth of these eastern redcedars and salt cedars up in those watersheds, the water flow to Oklahoma City and down the North Canadian River has been greatly depleted,” Emmons said.
The state has done some work to understand the spread of the trees in the past. In 2002, a Governor’s Task Force surveyed the number of eastern redcedars across Oklahoma.
“Honestly, there's just not enough financial resources to deal with it,” said Trey Lam, the executive director for Oklahoma’s Conservation Commission.
Lam said House Bill 2239 is a good start. The bill passed off the House floor last week. Authored by Republican Mike Dobrinski, R-Okeene, the bill lays the groundwork to remove eastern redcedars and similar species from around the North Canadian River. Dobrinski estimates the project will need about $600,000 from the state.
Sen. Casey Murdock, R-Felt, authored a second redcedar management bill, Senate Bill 454. That bill is still making its way through the senate.
“That one is basically a ‘clean up your own backyard,’” Roberts said. “They've charged the state agencies with assessing their own properties or maybe their leased land, and turn that report in in a year.”
Redcedars are indigenous to Oklahoma, but evolving land use and climate change have caused their rapid spread over the last 50 years. Historically, frequent wildfires and prescribed burning practices kept the trees in check. But in the past century, fire suppression has allowed the trees to spread.
People have also helped the trees spread. Their resilience during drought makes them a good windbreak in the grasslands of western Oklahoma, so some people plant lines of them in their fields.
“I meet people who flat out do not know that this is a problem for our state,” Roberts said. “They think the trees are pretty and they actually plant them on their property because it's a nice landscape.”
Lam said ecosystem shift poses a threat to native wildlife, including deer, quail and the lesser prairie chicken.
“It takes away their natural habitat,” Lam said. “It allows predators to roost there. For deer, it takes out their natural feeding grounds because there is grass growing.”
But Zou says all those trees are built out of carbon that could otherwise find its way into the atmosphere, so it’s important to consider that environmental benefit against the water costs. In drier regions, the balance is usually negative.
Roberts is optimistic HB 2239 is a step toward better eastern redcedar management. In a carrot-and-stick scenario, she said policies to slow the trees’ spread across the state have acted as the carrot.
“They just hadn't done a stick yet,” Roberts said. “And so now the stick is let's get rid of some of the trees, man.”
But there are challenges to management. Using machinery to cut down trees is expensive, and Lam says it’s hard to get people on board with prescribed burns.
“Really, the most economical way is using prescribed fire,” Lam said. “We can do that much cheaper than mechanical, but we really need to get an acceptance by all people in rural communities because fire is so scary.”
Ultimately, House Bill 2239 sets up a small science experiment. After the Conservation Commission removes harmful woody species from the North Canadian River Watershed, the state will be able to compare the results to the Cimarron and South Canadian River Watersheds, which will keep their trees.
“I think we've lost so much land to the eastern redcedar that once we start to show some success, I think there's going to be the public can really appreciate it and want to invest in it further,” Lam said.
But first the bill needs to make it through the Senate and get the governor’s signature.