Timber industry threatened by unwanted, invasive weed

A $494,000 U.S. Department of Agriculture grant will study how the spread of cogongrass af­fects Alabama's pine forests. In recent decades the health of many loblolly pine forests in the state and Deep South has been deteriorating, said Stephen En­loe, invasive plant specialist at AU's College of Agriculture.

Forestry is the state's top manufacturing industry, ac­cording to the Alabama Forest­ry Commission. There are about 22.7 million acres of timberland in Alabama, accounting for about 70 percent of the total land area of the state.

"The effects of cogongrass is ecological and economic," Enloe said. "Most of the timberland in Alabama is privately owned. The pine decline has a real im­pact on the pocketbooks of peo­ple who look to their timber as sources of income and retire­ment."

Enloe said that when cogon­grass is left unchecked in an area, it will crowd out native plants. "It grows in dense mats and it burns much hotter than our native grasses, so it creates a fire hazard as well," he said.

Enloe is conducting the re­search with Nancy Loewen­stein, a forest ecologist and in­vasive plant specialist; Lori Eckhardt, a forest pathologist and entomologist; and David Held, an entomologist.

A native of Asia, cogongrass first was discovered in Alabama in the Mobile area during the early part of the 20th century. It is believed the grass was used in packing materials coming into the Port of Mobile. For decades the noxious weed spread slowly through southwest Alabama and southeast Mississippi, said Stephen Pecot, communication director for the Alabama Cogon­grass Control Center.

Then Hurricane Ivan hit the Gulf Coast in 2004. Since then, the grass has spread through the southern half of Alabama and is widespread in Mississip­pi, Florida and Georgia, accord­ing to the Center for Invasive Species and Ecosystem Health at the University of Georgia. Co­gongrass also has been found in Louisiana, Texas, Tennessee and the Carolinas, data pro­vided by the center shows.

The recovery and cleanup ef­fort after Ivan brought help, and earthmoving machines, from throughout the region. When those machines returned home, they carried the grass with them to establish new colonies.

Pecot is taking part in a $6.28 million federally funded effort to control and eradicate the grass from the state. The grass covers about 100,000 acres in 32 of Alabama's 67 counties.

Eradication efforts, most of­ten herbicide spraying to kill the grass, will begin in mid-June, Pecot said.

"Cogongrass is very hardy. You just don't spray it one time and walk away," he said. "It will take repeated sprayings over several years to get patches un­der control and finally kill the roots of the grass."

The threat the grass poses to pine forests is multi-fold, Enloe said.

"We know that cogongrass and the increased risk of in­tense fires it presents plays hav­oc on a forest system's natural vegetation," he said. "But no one has looked at whether there's a cascading effect on the species and populations of in­sects. ...

"We want to find out how co­gongrass infestations, as well as the herbicides and other man­agement strategies being used to control the weed, alter insect diversity and abundance (affect) those loblolly pine forests show­ing symptoms of pine decline."