Collembola population levels 7 years after installation of the North Carolina Long Term Soil Productivity Study

Collembola are among the most abundant microarthropods in terrestrial ecosystems and have been shown to affect litter decomposition and nutrient release rates. Previous work on the Croatan National Forest Long Term Soil Productivity (LTSP) study indicated organic matter removal and vegetation control treatments affected collembolan populations. The present study isolated important factors within these treatments and determined if differences in collembolan populations by treatment persisted over time. Collembolans were extracted from litter and enumerated on both a per area and volume basis for 1 year. Litter volume, quality, and nutrient concentration, in addition to treatment effects of organic matter removal, soil compaction and vegetation control were tested against numbers of Collembola. Organic matter removal and vegetation control treatments had a significant negative effect on populations during the late spring, summer, and early fall months, whereas compaction had no significant effect. Physical litter characteristics, nitrogen, phosphorous, and carbon to nitrogen ratio were consistently significantly correlated to collembolan populations. Results indicate removal of the fermentation and humus (F, H) layers not only decrease the volume of living space but also make Collembola more susceptible to dry periods, and this effect continues even after reestablishment of the forest floor litter.