Relative abundance and seasonal activity of earthworms (Lumbricidae and Megascolecidae) as determined by hand-sorting and formalin extraction in forest soils on the southern Appalachian Piedmont

The relative efficiency of different sampling methods for earthworms may vary with site characteristics, season and earthworm species. We conducted a study in which earthworms were collected by hand-sorting and by formalin extraction in a successional, mixed hardwood-pine forest. The efficiency of each collecting technique was assessed in terms of seasonal trends, soil physical properties and species collected. Earthworm community age structure and seasonal temperature and moisture trends were the factors most integral to the efficiency of each technique. Results indicate that for the part of the year in which small juvenile earthworms were most abundant (November-May), hand-sorting was far superior to formalin extration. However, for the remainder of the year, the efficiency of the two techniques did not vary significantly. The formalin extraction method was more effective than hand-sorting for the collection of Lumbricus terrestris L., but not for any other species. Soil physical properties such as pH and texture, while important in distributional patterns of earthworms, did not have a significant effect on the efficiency of the collection techniques.