Terrestrial macroinvertebrates captured with a baited ramp-pitfall trap from five limestone caves in North Alabama and Georgia (USA) and their association with soil organic matter

Abstract

Abundance and species richness of terrestrial cave invertebrates are not well known but are thought to be constrained by nutrient (food) supplies. A standard sampling procedure for collecting cave invertebrates does not exist. The majority of cave systems in the southeastern USA (e.g. Alabama and Georgia) have not been extensively sampled for invertebrates. We tested a baited ramp-pitfall trap for collecting terrestrial invertebrates from caves and investigated whether macroinvertebrate abundance and species richness follow total organic matter (TOM) levels from cave soils. In 14-day sampling periods, we captured 21,204 invertebrates from 14 orders comprising at least 44 species from five caves in north Alabama and Georgia. Diptera was the most frequently captured order, comprising 18 species and over 91% of our captures. Overall, our traps were successful at sampling terrestrial invertebrates from caves; however, species richness and abundance did not always correlate with TOM concentration.