What Are Invasives?


Aggressive invasions of native and exotic shrubs such as tamarisk, Russian olive, eastern redcedar and reeds are causing problems on western Great Plains rangelands. They hog the water, shade the sun from nurturing the grass, and disorient game and nongame wildlife. These pests adversely impact ag economics, the ecology, and native wildlife on the Plains.

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This is Playa Country — a weekly look at the wildlife, wetlands and prairies of the western Great Plains, and the people who manage them — brought to you by Playa Lakes Joint Venture, an organization dedicated to conserving birds and bird habitat.

Today’s topic is invasive shrubs, those native to the Plains, and exotics. The people who know about these things say the shrubs are “invasive” because they’ve come into a landscape, typically introduced by mankind, then dominated and even bullied ecosystems. These invasives impact production agriculture and ranching, change watersheds, and disturb native wildlife.

Trees like the indigenous eastern redcedar, and exotics like tamarisk or saltcedar, the Russian olive, and the reed plant. Listen to Oklahoma State University Professor Terry Bidwell, an extension rangeland management specialist.

“Russian olive and saltcedar are actually plants that were brought in from other continents, and they’ve escaped from where they were planted. They were brought in as ornamentals. Eastern redcedar, on the other hand, is a native plant, but historically was very rare. It only grew in places that fire could not reach. With fire suppression, of course, redcedar spread all over the landscape.

“The main things that any of these plants change, where the negative impact comes to the environment, is a change in habitat structure. Wild animals key in on visual cues, and when you get a different structure, like along the Canadian River, it will displace some species and perhaps allow other species to come in.”

Tamarisk, eastern redcedar and Russian olive have invaded the banks of the Canadian River — and in Nebraska, phragmites, the common reed plant, is choking waterways. Upland, the eastern redcedar saps water and decreases the carrying capacity of pasture land according to biologist Kirk Schroeder, with U.S. Fish and Wildlife Service at Grand Island.

“Those invasives may be one of the largest natural resource issues that we may have in Nebraska coming up. As more and more of those trees invade more and more of those prairies, we’re losing grazing land, we’re losing a lot of grasslands for wildlife habitat, we’re losing revenue. For a number of our ranchers, those trees invade and take over more and more and more acres of those grasslands that could be grazed.”

This problem of invasive shrubs is so widespread, and the cost to control these weeds is so expensive, federal and state agencies and nonprofit organizations like Pheasants Forever and the National Wild Turkey Federation, are partnering to help foot the bill for private landowners to control these weeds. That’s what’s happening along the Canadian River in Texas and Oklahoma according to Gene Miller. He’s a biologist with the National Wild Turkey Federation. His group organized the Canadian River Cooperative Weed Management Area.

“Individually, none of these agencies or none of these entities or National Wild Turkey Federation… none of us are large enough to tackle these huge landscape problems. But together, through these large collaborations, we can bring different things to the table to attract landowners for voluntary participation. All of this is happening along this reach of river in Texas and Oklahoma totally and completely through voluntary participation by private landowners.”

Conservation agencies make funds available to landowners to help defray weed control expenses.

You’ve been listening to Playa Country, a weekly show about the wildlife, people and landscapes of the western Great Plains. This program is made possible by the Playa Lakes and Rainwater Basin Joint Ventures.

Original broadcast: June 2012

Posted: December 1, 2013
Topics: Invasive Shrubs