Abstract

Earthworms are known to have important impacts on leaf litter decomposition in terrestrial systems. However, their ecological roles in semiaquatic habitats have not been previously addressed. In North America, this semiaquatic habitat is dominated by earthworms of the family Sparganophilidae. These earthworms have been essentially ignored, and their basic biology and taxonomic relationships are not well known (although recent advances have been made). We designed an experiment to determine the effects of sparganophilid earthworms on decomposition of riparian litter.  In this experiment, we manipulated earthworms (presence or absence), and position of litter (surface or buried) in a fully factorial mesocosm study. Earthworms, sediments and leaf litter used in the study originated from Scull Shoals Experimental Forest in central Georgia, USA, which is representative of the wider Southern Piedmont physiographic region. Mesocosms were constructed to closely simulate stream shore conditions, consisting of saturated and unsaturated sediment. A mixture of hickory (40%), red oak (18%), loblolly pine (22%) and white oak (18%), litter was placed into mesh bags for use in the decomposition assay.  Mass loss data were collected, along with water chemistry data (alkalinity, pH, NO3 and NH4) to evaluate the influence of earthworms on these important ecosystem variables.

Citation

Carrera-Martínez, R.R., M.K. Taylor, D. Markewitz, L.A. Sutter, and M.A. Callaham, Jr. (2019): Influence of earthworms (Oligochaeta: Sparganophilidae) on decomposition of riparian leaf litter. Society for Freshwater Science annual meeting, Salt Lake City, Utah, May 2019.