Every time Randy Cash tipped the backhoe’s front loader, reddish dust billowed in the late afternoon sunlight. It lightly coated the 20 or so people watching Cash, leaving a fine grit on the tongue and a faint earthy smell on skin and clothes.

Back and forth across a newly dug depression, he shifted bone-dry dirt to a low crescent-shaped berm that marks the edge of a future wetland habitat. Cash, a supervisor in Sweet Briar’s physical plant department, lent his expertise on the backhoe for the Vernal Pond Building Workshop at the College on Saturday, Sept. 29. The biology department, led by Professor Linda Fink who helped plan and host the event, sponsored the workshop.

U.S. Forest Service wildlife biologist Tom Biebighauser broadcasts grass seed during a project to restore a wetland habitat on Sweet Briar's campus.Led by U.S. Forest Service wildlife biologist Tom Biebighauser, a group of ecologists, biologists and conservationists from half a dozen states came together to restore habitat for native amphibians and other animals on the College campus.

They also came to learn from Biebighauser how to do it, so they can repeat the effort elsewhere. He has restored many wetlands and written books on the subject.

Mike Hayslett, an expert on vernal pools in Virginia, coordinated the workshop. He watched Cash gingerly deposit a dead tree so that its ragged roots were in the bowl.

“That’s what we want — half in, half out,” Hayslett said. “We always save a big chunk of organic material to put in the wetland. That helps jump-start the food web.”

It’s also structure for frogs and spotted salamanders to attach their eggs to, and a place for turtles to hang out. Vernal pools typically dry up for part of the year and it’s this feature that makes them critical breeding grounds for many animals. The water stays long enough for them to reproduce but not to support predatory species such as fish.

The crew also piled smaller limbs and debris around the pond’s center, which Biebighauser estimates will be about 14 inches deep. They raked the edges, then broadcast winter wheat, Indian and switch grass and partridge pea seed to stabilize the disturbed soil. Finally, they scattered hay for mulch.

The berm is the rim of a 6-foot dam — 4 feet of it underground to catch ground water flowing downhill. The backhoe and a bulldozer were used to dig down to the impervious soil level or hardpan. They carved a curved trench, then backfilled, packing the soil down hard to construct the dam. The technique is called core trenching.

The project is a restoration, because it lies in a field that appears to have been drained, possibly for cultivation. It is between the Nature Center and Elijah Road, adjacent to Woodland Road.

Biology Professor Linda Fink both participated in and helped organize the Vernal Pond Building Workshop at Sweet Briar.Round clay drainage tiles were found in the field, which today is mowed for hay. Six-sided clay tiles also were discovered in a narrow wood growing up along a creek next to it. The tile suggests to Biebighauser and Hayslett that small springs that once kept the field wet were buried to divert water for crop production.

Although it’s not known when the tile was installed, Hayslett noted that both the pond habitat and the archaeological find are great new features for an interpretive trail that was opened along the wooded stream last spring.

Barring drought and hurricanes, Biebighauser thinks the pond will keep water for about 10 months most years — long enough to allow wood frogs and spotted salamanders to lay eggs but not long enough for competing bullfrogs.

“It’ll take about five years to really look good but it’ll look OK a year from now,” Biebighauser said. “You’re going to see bright green sedge, bulrushes and wildflowers. When you come out here at night you’ll hear the frogs and toads calling.”

He expects shore birds to feed in the mud on insects during the dry season. Mosquitoes won’t be a problem because their eggs and larvae will be eaten by salamanders, dragonfly larvae and bats at night, he said. “Mosquitoes will check in but they won’t check out.”

The restored habitat is both an educational and ecological resource, he said. “What we’ve been able to do here is bring the field trip to campus.”

It should be around for a while, too. “This wetland could be here for hundreds, if not thousands of years,” he said. “It should require no maintenance.”

– By Jennifer McManamay, SBC staff writer