Symptoms of climate change in Southeast fuel increase in invasive plant species

• Cogon grass, a major invasive species in Georgia, reduces native plant diversity and increases fire risk.
• Planting native species is recommended to support local wildlife and prevent invasive plant takeover.

Symptoms of climate change include extreme heat, drought and extreme weather, all of which can significantly impact plant species.

“It’s kind of hard to pin it down, because climate change is so complicated,” said Eamonn Leonard, senior wildlife biologist for the Georgia Department of Natural Resources, Wildlife Resources Division. “It changes so many different things. From storm frequency to moisture to drought in general. I think invasives are able to sort of capitalize on changes that our native plant species aren’t able to.”

Invasive plant species is any species that if introduced is likely to cause environmental harm, according to experts with Georgia Invasive Species Council. 

Leonard said a native plant species is a plant that naturally occurs within a specific region or ecosystem due to natural processes, without human intervention.

“With the warming climate, you can have plant species that are normally relegated to Florida now can grow in Georgia,” said Leonard. “We’re already seeing some native plants moving. It’s the same thing with invasive species. They can’t deal with cold temperatures. Now that we might not be having those freezing temperatures, they could survive farther north. So there’s definitely an impact.”

Invasive plant species in Georgia include:

• Cogon grass
• Chinese tallow
• Climbing fern
• Kudzu
• Showy rattlebox
• Thorny olive
• Alligator weed

“One of the worst non-native invasive plants in Georgia is called Cogon grass,” said Leonard. “We’re really focused on making sure it doesn’t take over. It’s the only invasive that we have funding to treat. The funding takes care of the problem with no cost to the landowner.” 

The way invasive plants become measurably negative is when they crowd out native plants. The Cogon grass in particular, said Leonard, greatly reduces that natural diversity.

“It takes over a certain area and pushes out all the native plants,” he said. “Our native wildlife have evolved to need a diversity of plants for pollination, host plants and for nest material. When you wipe that slate clean, you’re just left with one plant. This can reduce the habitat quality for our native wildlife.”

Cogon grass is a fire hazard

Cogon grass poses such an outsized problem among invasive species because it is highly flammable, said Leonard.

“A lot of our forests in the Southeast do have a relationship with fire,” he said. “That’s very important. They were maintained by fire every three to five years. But a very low intensity fire. Cogon grass burns incredibly hot. It burns much hotter than our native plants..”

Chinese tallow an be agents of significant change

Chinese tallow trees were intentional transplants in Georgia.

“It’s also called the popcorn tree,” said Leonard. “It’s a tree that was brought here because it has a really nice fall color. It also had promise for producing a vegetable tallow, or like a wax to use in soap making and for candles.”

Leonard said the Chinese tallow changes the structures of communities.

“It produces hundreds of thousands of seeds at a very young age,” said Leonard. “It stays reproductive for a very long time. It can grow in a very wide variety of habitats. It really just crowds out our native plants. So if an area is a grassland, it turns it into a forest, which is just a very different environment.”

Kudzu is seemingly everywhere

Kudzu is an invasive vine native to Asia, according to experts with the Georgia Invasive Species Council.

It’s an aggressive vine that can quickly cover and smother native vegetation, impacting ecosystems and infrastructure. Organizations like the Georgia Invasive Species Council and The Nature Conservancy are dedicated to removal and preventing further spread.

Climbing fern can also be a fire hazard

As a fern that climbs, as it name suggests, Leonard said they were popular garden plants for years.

“But one of the problems with that, similar to the other two, is that it crowds out native plants,” he said. “Since we manage our ecosystems with fire, climbing fern can climb up trees. It brings that fire into the tree canopy, where fire normally wouldn’t get that high. It creates what we call a fire ladder. So it can create a canopy fire.”

Native plant species in Georgia include:

• Live oak
• Southern magnolia
• Redbud 
• Silver Bell
• Black-eye-susan
• Milkweed

Leonard said native plants are a better way to go for replanting.

“The more native plants we have in the environment means fewer non-native invasives that could take over if there’s another disturbance event,” he said. “It’s just a better idea to plant natives. We know they’re from here and they’ll never become invasive. Native plants support local butterflies and other wildlife pollinators.”

This reporting content is supported by a partnership with several funders and Journalism Funding Partners.

Erica Van Buren is the climate change reporter for The Augusta Chronicle, part of the USA TODAY Network. Connect with her at EVanBuren@gannett.com or on X: @EricaVanBuren32.