Cedar City » Zion National Park lures visitors with a landscape of towering redrock studded by vibrant greenery and slot canyons carved by wind and water.

But there's another "scape" in Zion, one that is now getting serious scientific attention: birds singing, water running over ledges, leaves rustling, the echo of thunder in sandstone canyons and the sound of a jet flying 30,000 feet overhead.

For several years, the southern Utah park has been working on a "soundscape" management plan that, if adopted, would make Zion the first national park in the U.S. to set standards for protecting its unique acoustics.

Frank Turina, a natural resources planner with the National Park Service (NPS) in Fort Collins, Colo. who specializes in acoustics, is among experts analyzing information collected in Zion. Sound, he said, is a park resource just like air, water and wildlife.

"It has its own inherent value," he said in a telephone interview. "When we look at the park we see an acoustic resource and ambient conditions based on the data that can help establish what we want the park to sound like in certain areas."

He said while smaller national park properties are looking at sound plans, nothing is being done on the "full-blown scale" of Zion.

"This is a fairly new area of science," said Turina of the project. "Soundscapes may be invisible, but are noticeable."

Last December, the NPS published an online special report on the need for more research on soundscapes at national parks.

"Noise impacts the acoustic environment much as smog affects the visual environment because it reduces the auditory horizon for both visitors and wildlife. In many cases, hearing is the only option for experiencing certain aspects of our environment, such as wildlife that can be heard at much greater distances than they can be seen," wrote NPS staffers Vicki McCusker and Kerri Cahill in a piece about the importance of including soundscapes in park planning.

Establishing standards, the planners argued, will allow parks ammunition to deal with external sources of noise. "Proper management of soundscapes is becoming more complex and challenging as threats to acoustic resources, both internal and external to park boundaries, increase. Planning is an essential step in addressing these threats."

And humans aren't the only creatures affected by noise. Research on birds and mammals indicate human-caused sound can prompt behavioral changes.

"For example, oil and gas development platforms may disturb a limited area of vegetation, but the noise footprint is much larger. The quiet spaces within a developed field may be too small and too far apart to support species that are sensitive to noise, and loud areas may form barriers to migration and dispersal," said a paper by staffers at the Department of Fish, Wildlife, and Conservation Biology, also published as part of the NPS special online report.

At Zion, an environmental assessment is under way to define the park's existing ambient soundscape and provide objectives and standards for future management of the sound environment.

Since 2001, the park has been using portable, solar-powered monitoring stations to record sound as well as measure weather and wind speed, said Kezia Nielsen, an environmental protection specialist at Zion.

The devices monitor an area 24 hours a day, for up to 28 days at a time. The information is then analyzed to map sound in the park.

Nielsen said the stations have recorded everything from helicopters to desert bighorns colliding head-on, to symphonies of cicadas to rockfalls.

The environmental assessment will consider sound in the 84 percent of the park that is back country, which is managed as wilderness, as well as the front country, which bears the greatest public impact.

She said such areas as visitor centers, entrance stations, campgrounds and other front zones can get special consideration for what's appropriate to enhance the natural experience expected by park visitors.

At some national parks, such as a battlefield, cannon fire would be appropriate part of the soundscape, Nielsen said.

mhavnes@sltrib.com