Restoring rare trees in works at Congaree National Park

COLUMBIA, SC - Biologists want to restore rare longleaf pine forests at Congaree National Park by clearing dense underbrush on the preserve’s northern boundary.

Controlled fires, herbicides, chain saws and heavy equipment would be used to eliminate unwanted plants on a sliver of the national park, according to a federal plan now out for public review.

Clearing the jungly mass of sweetgum trees and brush will create ideal growing conditions for longleaf pines, majestic trees that once dominated the southern landscape, the National Park Service says. Congaree National Park has a few longleafs now, but not enough, officials say.

“It’s important to us to not only maintain what we have, but to restore some of that ecosystem,’’ park resource management chief Liz Struhar said.

Longleaf pines, recognizable by their thick trunks and long spindly needles, were common in South Carolina centuries ago, but European colonists chopped down vast stands as they developed farms and built cities after settling in America. Today, less than 4 percent of the original longleaf pine forests remain in the Southeast.

The National Park Service says planting more longleafs will add another scenic element to Congaree National, while helping to eventually bring back some animal species. Longleaf pine forests are considered by many to be among the most picturesque in the country. Trees in mature longleaf forests are widely spaced and are underlain by low grasses, creating a park-like look.

One species that could benefit is the red-cockaded woodpecker, an endangered bird that hasn’t nested at the park in years. Red-cockaded woodpeckers prefer older longleaf pines, which provide good cavities to hatch and raise young. The open, park-like floor of a longleaf forest also keeps predators away from the woodpeckers.

“We know they are in places nearby, such as Fort Jackson,’’ Struhar said. “If we could get the ecosystem right, they would come back. We don’t have enough of those restored areas of the size trees they would like.’’

The area targeted for longleaf restoration would be on 1,200 to 2,000 acres of the more than 26,000-acre national park southeast of Columbia. Most of the park consists of flood plains and swamps dominated by old-growth hardwoods, some so tall it’s hard to see the tops from the ground. But the northern edge of the park has ample high-ground.

In the past, preserve managers have tried to clear the brush on Congaree Park’s northern rim by intentionally setting small fires, but that hasn’t worked, federal officials say. Every time they would burn an area, undesirable vegetation would soon sprout again, officials say.

“Longleaf pine forest restoration efforts have not been as effective as desired,’’ according to a National Park Service overview of the plan that also says Congaree Park staff “cannot effectively achieve forest and restoration objectives through prescribed burning alone.’’

Using herbicides might raise a few questions because much of Congaree National Park is wilderness area and its creeks, while generally clear-running and clean, have shown signs in recent years of pollution from wastewater plants, septic tanks and farms upstream near Columbia. In 2014, scientists reported finding traces of pharmaceuticals and farm chemicals in some park creeks.

Struhar said the park will hand spray herbicides carefully on high ground, away from creeks or other water bodies.

Dana Beach, director of the S.C. Coastal Conservation League, said limited use of herbicides could help, as long as they are properly managed, in the effort to restore longleaf pines.

In addition to helping clear a path for longleafs to grow, the plan to eliminate vegetation near the park’s northern border could reduce the threat of intense forest fires that could affect neighbors, federal officials say. Struhar said that part of the plan is of equal importance to the establishment of longleaf pines.

Before any changes are made in how the park clears brush for longleafs, federal officials need public input. The Park Service has scheduled public meetings for Jan. 25 and 26 in Richland County to gauge public interest.

An environmental assessment is being conducted and would be available for review in late 2016. The proposal to allow more ways to clear brush is part of a larger fire management plan for Congaree National.

Struhar noted that plans to use herbicides and mechanical clearing equipment aren’t final and could change, depending on public comments and the results of the environmental study. It would be at least 2017 before a new fire management plan takes effect.

Beach said if the new brush-clearing plan works, it might not be needed for the long-term. If the park can knock back problematic plants enough to re-establish a longleaf forest, it might eventually be able to use prescribed fires periodically to maintain the area — without the use of herbicides and mechanical equipment, he said. Struhar agreed.

Prescribed fires, which are intentionally set by forest managers, are considered important to managing woodlands today and are a departure from past federal policies. Burning in pine forests kills out vegetation on the woodland floor, but longleaf pines survive because they are more tolerant to fire.

As the U.S. developed, however, the government established policies to fight all wild forest fires. That allowed thick vegetation to develop that would have been destroyed if fires had been allowed to burn. When vegetation is too thick, it can lead to more dangerous and intense forest fires.

The problem in some areas today is that the vegetation is too thick to clear only with prescribed fire. So forest managers say they need additional tools. When those areas are cleared, a regular burning schedule can be developed that will maintain forests in a more natural state, they say.

“If you haven’t managed things well for a long time — and most properties haven’t been managed for longleafs — you get sweetgum trees and other difficult to burn species,’’ Beach said.

Staff photographer Tracy Glantz contributed to this story.