They're a new breed of ginseng diggers across the USA, described as a rough and tumble lot looking to parlay rising Asian demand for the rare plant's roots into a fast buck.

Police say more diggers are pushing into the back country in search of wild ginseng, ripping up even the smallest plants and ignoring property lines.

Their slash-and-burn tactics have left property owners enraged and biologists worried about the slow-growing plant's long-term survival in America.

In Ohio, prosecutors charged one landowner with gunning down a man he believed was stealing ginseng.

"We're not finding big, healthy populations. It was there, and a lot of it has been taken," said Nora Murdock, an ecologist with the National Park Service.

Asians believe the multi-pronged root has medicinal properties that help improve everything from memory to erectile dysfunction.

"It's lucrative to spend a day in the woods and walk out with $500 of ginseng in a bag when you don't have a job," said Wisconsin conservation warden Ed McCann.