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A Delicate Balance: Nature And Technology

The mention of Kennedy Space Center (KSC) or Cape Canaveral Air Force Base — jointly known as the Cape Canaveral Spaceport — is likely to conjure similar images in the minds of most Americans: spacecraft, launch pads, F-16s and other high-tech, scientific marvels. After all, the Cocoa Beach, Fla., area is best known for 50-plus years of advances in space travel. Well, that and I Dream of Jeannie.

The size of KSC, 140,000 acres, and the adjacent Cape Canaveral Air Force Base at 90,000 acres, is impressive. Visitors are awed by KSC's twin space shuttle launch pads and the Vehicle Assembly Building, which (by volume) is the third largest building in the world.

Within the confines of KSC, surrounding its man-made wonders, is one of Florida's most protected and cherished wildlife preserves: the Merritt Island National Wildlife Refuge. Home to more endangered native plant and/or animal species than any other park in Florida, the refuge enjoys environmental protection and usage restrictions aimed at safeguarding the area for generations to come.

Unfortunately, one of the greatest threats to the refuge is alien invaders. No, not from space-traveling hitchhikers, but aliens that at first appear to be an innocent part of the Florida landscape. Known as “non-native plant species,” alien invaders, such as Brazilian pepper trees, present a much greater danger to the area's native species than anything from outer space.

Luckily, those involved in maintaining the wildlife preserve and controlling invasive species have their own space-age tools, including selective low-volume herbicides that work to restore native vegetation in sensitive and threatened habitats.

Power Solutions

Brazilian pepper has been especially problematic for Florida Power and Light (FP&L), who owns and manages electric transmission lines that cross areas of the refuge. The tree species grows thick and spreads quickly, reaching heights that could interfere with power line performance and complicating access to right-of-ways (ROWs) for FP&L workers.

Dan Marsh, a senior utility arborist for FP&L, manages 2,600 miles of transmission lines in north-central and north Florida, and recently worked on a stretch of line within KSC.

“We need to keep a 110-foot-wide ROW clear under the transmission lines. Brazilian pepper has made that tremendously difficult,” Marsh said. “Once it starts growing in an area, Brazilian pepper out-competes native vegetation and becomes overwhelming. Under electric transmission lines, it restricts access and can cause power line interruptions if allowed to grow tall enough to get into the conductors.”

To control the spread of Brazilian pepper in the refuge, Marsh decided to try broadcast foliage herbicide applications, using products labeled for this particular difficult species. He chose two products — Arsenal® herbicide and Habitat® herbicide from BASF Professional Vegetation Management (BetterVM) – because they are designed to help control invasive species and restore native vegetation in sensitive and threatened wildlife habitats, such as the refuge.

In 2003, Clear Waters, Inc., managed the project and applied herbicides within the refuge for FP&L. Every decision was made knowing that the goal was to control as much of the invasive species as possible while limiting the amount of mechanical and chemical impact to the land. Releasing native vegetation and allowing it to re-establish in the treated areas was also important.

Because the area was thick with 15- to 25-foot-high Brazilian pepper, Clear Waters first had to wait for a special mowing device to cut a path through the middle of the ROW, said Trace Wolfe, vice president of Clear Waters. The mowing machine (made by GyroTrac®) exerts only about three pounds of ground pressure, which helps limit the impact of mowing in sensitive areas.

“It doesn't leave much, if any, of a footprint in the soil,” Marsh said. “It allowed the applicators to get through the refuge ROW areas without disturbing its many important historical sites, including Indian burial grounds.”

Protecting desirable vegetation under and around the power lines, such as mangrove trees, was also important. Once much more prevalent, mangrove trees act as a unique habitat for many creatures, including birds, mammals and fish. The trees also support effective nesting and breeding by offering protection for young birds and fish.

“We used Arsenal with a low-volume application technique in the non-wetland areas of the refuge. It allowed us to specifically target the invasive species we wanted to control,” Wolfe said. “In the aquatic and shoreline areas, we used Habitat. The BASF products allow for the use of less active ingredient per acre than other herbicide treatments, and Habitat breaks down quickly in water so there is little impact on aquatic species.”

The first season, Clear Waters made herbicide applications with a combination of amphibious track equipment, pickup trucks and backpack sprayers. But the following year, applicators were able to use all-terrain vehicles and pickup trucks to touch up and apply spot treatments. “It looks great now,” Wolfe said. “It will be awhile before we have to come back.”

The new strategy far outperformed past vegetation management techniques, such as mowing.

“Mowing is only a short-term option for controlling Brazilian pepper,” Marsh said, “and not a good option at that. A year after mowing, you can have four feet of regeneration with twice the density. Other options, such as hand-cutting or basal bark herbicide treatments, are too labor-intensive and expensive. Fortunately, low-volume broadcast applications give us the long-term control we're looking for.”

It Is Rocket Science

According to Glenn Willis, an entomologist in charge of pest control at KSC, Arsenal is used at a number of other sites at KSC to control unwanted vegetation.

“We utilize Arsenal in tank mixes for bareground areas,” said Willis, who works for Yang Enterprises, a subcontractor through Space Gateway Support (SGS). SGS is the city manager for the Spaceport and contractor of choice for the Joint Base Operation Support Contract. “We have fence lines, fuel lines, the crawler track, launch pads and many other areas that need to remain free of brush and/or weeds for safety reasons.”

For example, Willis uses herbicides to maintain bareground gravel around lightning sensing devices. “Lightning sensors are very important at KSC,” he said. “Storms can come in quickly and create safety hazards, especially around the fueling areas.”
The sensors are designed to detect when conditions are ripe for lightning. If they signal a lightning warning, NASA managers can stop fueling operations immediately. But, if the lightning sensors are even partially covered by vegetation, they can't operate effectively and safety is compromised.

Willis also used Arsenal at the site of a wind profiler, which essentially tracks wind patterns by sending radio waves into the sky. Soil in and around the wind profiler must remain moist to get a good signal. But the moisture also helps unwanted vegetation grow, disrupting the profiler. “Arsenal worked like a charm and we've been using it ever since,” said Willis.

KSC, Cape Canaveral Air Force Base and the Merritt Island National Wildlife Refuge are a symbol of modern technology and pristine wildlife habitat. Consequently, those responsible for vegetation management on the land seek the best management strategies and focus on protecting the precious native habitat.