Influence of earthworm activity on the abundance of collembola in soil

Effects of earthworm activity on the abundance of collembola were investigated in laboratory experiments and a field experiment on arable land. In the laboratory two earthworm species Aporrectodea caliginosa and Lumbricus terrestris were involved. Folsomia candida could choose between columns of soil which were worked and inhabited by earthworms, those which had a cylindrical, artificial soil pore and those that remained untreated. Working basically with the same design, vessels varied in shape and size. Experiments with A. caliginosa were carried out in planar plastic cuvettes that were divided into three segments, each containing one of the columns of soil described above. Triplets of plastic tubes were used for L. terrestris in the same way. While the soil — a Parabraunerde from loess — was the same in all laboratory experiments as well as in the field experiment, pore space, gravimetric water content, diameter of artificial soil pore and duration of experiments varied. No extra food was provided for the animals. For evaluation the soil columns were fractioned into several depths and extracted after the Macfadyen method. The results showed generally preferences of F. candida for earthworm burrows. field experiment near Braunschweig (northern Germany) the natural abundance of earthworms was increased by releasing additional earthworms on plots representing a tramline and a traffic-free control. Two months later eight soil cores were taken from these two plots and from two control plots without raised earthworm abundances. Extraction of collembola was carried out as above. ences in abundances of collembola occurred only in the heavy compacted plots.