Published on 01/10/01

Little Creatures Reveal Big Things about Wetlands

Large-scale logging can often affect the delicate balance of plant and animal life in nearby wetlands. But how much? A University of Georgia scientist says if you look close enough, some little creatures can tell you big things about wetlands.

Darold Batzer, an entomologist with the UGA College of Agricultural and Environmental Sciences, has spent the past four years hunting the state's wetlands in search of tiny, sometimes microscopic, invertebrates for answers.

Why Invertebrates?

Invertebrates, Batzer said, would be the first animals to show any changes in the wetland ecology. They feed on plants and are closer to the beginning of the food chain than a hawk or a frog.

"Invertebrates are a major link between plants and higher animals like birds, reptiles and amphibians," Batzer said. "So, they are kind of like the guts of the food web."

An invertebrate is an animal with no backbone. The most commonly known Georgia wetland invertebrate is the mosquito, but Batzer also looks for small crustaceans and fly larvae.

They're easy to collect, he said, and useful in looking for impacts. Batzer's hunting weapons are simple: a sweep net, plastic bags and alcohol to preserve samples.

"There are a lot of different kinds of invertebrates, and each kind gives you a lot of clues on what is going on in that habitat," Batzer said.

Depends on the Numbers

For instance, a water flea can tell you the loss of tree coverage in the wetland due to logging. Algae need sunlight to grow. A water flea feeds on algae. The number of algae depends on the amount of sunlight. And the number of water fleas depends on the amount of algae. Counting the water fleas can give you an idea on how much sunlight is hitting the wetland.

Batzer mostly investigates low-lying wetlands inside pine plantations. He studies a site for a couple of years to see how it operates before the timber is harvested. When the timber is cut, he returns to identify any changes.

"We see what impacts do occur: increased sunlight, increased nutrient runoff or some sort of runoff," he said. "We then look at ways to find out why those changes occur and ... ways we can reduce any changes."

Batzer has found some ecological changes in wetlands near timber harvesting. So far, though, he has detected no harmful impacts.

If there are negative impacts, he said, strips of trees could be planted to act like a buffer zone and protect the wetland. But a buffer zone could cost thousands of dollars.

"The research could affect many acres in Georgia," he said, "because there are literally thousands of these wetland ponds in the state."

Need More Valuable Clues

So far, the experiments are in the early stages, and more research must be conducted. But Batzer is hopeful he can identify the environmental changes affected by timber harvests in these delicate ecosystems in Georgia.

"People realize that wetlands are valuable resources and environmental benefits are hard to put into a dollar value," he said.

Georgia is the largest timber producer in the eastern United States. About 72 percent (17 million acres) of the state's forests are privately owned. Forestry is Georgia's largest renewable resource, with an annual impact of $19.5 billion on the state's economy.

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.