Definition of "denuded"

Harvester ants have brilliantly carved an enormous niche for themselves in nature and etched indelible images in mankind: images from cartoon depictions of a backyard volcano erupting with angry ants when their home is trespassed, to images of vast stretches of the American West marred with ant castles surrounded by denuded moats of dirt.

2016, Justin O. Schmidt, The Sting of the Wild, Johns Hopkins University Press, page 102f