Assessment of anecic behavior in selected earthworm species: Effects on wheat seed burial, seedling establishment, wheat growth and litter incorporation

Anecic earthworm species function as ecosystem engineers by structuring the soil environment, incorporating large amounts of litter and seeds into soil and, thereby influence the composition of plant communities. The aim of the present greenhouse experiment was to investigate the effects of three apparently anecic earthworm species on wheat seed burial, seedling establishment, wheat growth and litter incorporation. The three species differed substantially in their behavior and effect on plant establishment. Aporrectodea longa did not incorporate litter into the soil while Lumbricus terrestris (-69%) and Lumbricus rubellus friendoides (-75%) reduced the litter layer considerably during 9 weeks of incubation. Moreover, L. terrestris and L. rubellus friendoides buried more wheat seeds than A. longa. Fewer seeds germinated when buried by A. longa compared to L. terrestris. The behavior of L. terrestris and L. rubellus friendoides was characteristic for anecic earthworm species whereas that of A. longa rather resembled that of endogeic species. The present study is the first experimental evidence for anecic behavior in L. rubellus friendoides. (c) 2007 Elsevier B.V. All rights reserved.