Invasive plants crowding out Georgia plants, wildlife

By Lee Shearer
ATHENS, Ga. — Climate change gets the most attention nowadays when it comes to human-caused environmental destruction, but it’s only one of the ways humans are shredding ecological webs of life.

One that’s under-reported is the growing spread of foreign plants like privet, a nondescript Asian shrub a U.S. Forest Service scientist once compared to an atomic bomb in its ability to obliterate everything around it.

Used for more than a century as a landscaping plant — the Sanford Stadium hedge is one — seven species of privet have now made their way into more than 600,000 acres of Georgia forest and countless urban and rural yards.

Other plants, mainly from China and other Asian countries, have also reached millions of acres in Georgia in a kind of slow-motion life-and-death struggle playing out in various scenarios not just in Georgia but across the world.

They get here and spread in various ways. Many brought here for planting because they’re pretty. Privet and dozens of other invasive exotic plants are a big and under-rated factor in why scientists are seeing steep declines in insect numbers and bird numbers in Georgia and elsewhere, says Georgia Department of Natural Resources botanist and ecologist Mincy Moffett.

“Invasive exotics is about extinction,” he said.

“We’re losing the Southern forest,” said Athens-Clarke County Ecological Resource Manager Mike Wharton.

When Wharton says forest, he’s not just talking about trees, but all the life in a forest — the birds that nest in the trees, the rabbits and voles beneath, the bugs or greenery they eat, even the soil micorganisms and worms.

As privet grows up in thickets, nothing can grow beneath it, and even the soil acidity is changed.

Forest researchers have found that the changed soil is more hospitable for invasive species of worms whose appetites accelerate litter composition and make soil harder, increasing stormwater runoff, Wharton explained.

Humans have been moving plants and animals around thousands of years, but the pressure on natural systems today from invading plants — privet, Japanese honeysuckle, English ivy and many more — is unprecedented, said Karan Rawlins, invasive species coordinator at the University of Georgia’s Center for Invasive Species and Ecosystem Health.

“People have always mixed things up, but in modern times it has sped up, more than a natural system can adapt to,” she said.

No one expects to be able to roll back the invasion, but state land managers, among others, are working to protect and restore what they can. Many landscapes still remain relatively untouched by non-native invasion.

Locally, the State Botanical Garden has been rolling back the exotic plants infesting its forests, and a volunteer group called the Weed Warriors saw native plants return to Athens’ Memorial Park as they worked over years to eradicate the park’s heavy load of privet, ivy and other exotics.

As Athens-Clarke’s Wharton spoke this summer, he watched a small army of volunteers from Athens’ Pilgrims Pride poultry processing plant toil for days in July heat removing privet and other invasive plants from a stretch of the North Oconee River near downtown Athens, giving a head start of years on what Wharton hopes will be a much larger restoration along the river.

When native plants return to the area, re-emerging or seeded with a recipe created by State Botanical Garden of Georgia conservationist Linda Chafin, the stretch will be a seed bank for native plantings elsewhere as Athens-Clarke land managers reclaim more exotic-occupied territory, Wharton said.

“As we pull it back, we’re going to see how beautiful this area is,” Wharton said.

Forest ecologists like Rawlins also hope state lawmakers can be convinced of how serious a threat invasive exotic plants really are.

Georgia is one of just four states that don’t have a noxious weed law that could reduce the sale and use of foreign plants known to be invasion threats.

Source: Invasive plants crowding out Georgia plants, wildlife – The Agusta Chronicle, 2019-09-30