A survey of the entrance pitch of Poulnagollum Pot found several distinctive vegetation sub-communities occupying different biophysical zones. These communities were found to be in stark contrast to the vegetation on the nearby surface, being defined by a rich variety of mosses, liverworts and woodland field-layer plants, and resembling the field and ground layers of semi-natural Ash climax woodland. After analysis of data collected in 2002, it was suggested that variation in the vegetation sub-communities was attributable to local but significant differences in soil reaction and water availability.