ABSTRACT
A conceptual model for the movement of organic carbon through a karst basin requires three main inputs: (1) localised flow of particulate organic carbon (POC) and dissolved organic carbon (DOC) through sinks and shafts, (2) diffuse flow of POC and DOC from soils and epikarst, and (3) deep groundwater inputs. Inputs of the localised and diffuse components were measured in the Postojna-Planina Cave System in Slovenia. Most DOC enters through streams entering the cave but diffuse flows from soils and epikarst is more generally distributed and appears to play an important role in subterranean food webs. Considerable spatial variation in DOC among epikarst drips was detected, and these differences were consistent through time. DOC concentration was not a good predictor of the abundance of copepods in dripping water.
