Impacts of Earthworms on Other Biota in Forest Soils, with Some Emphasis on Cool Temperate Montane Forests - Earthworm Ecology - page 230

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Impacts of Earthworms on
Other Biota in Forest Soils,
with Some Emphasis on Cool
Temperate Montane Forests

Dennis Parkinson

Department of Biological Sciences, University of Calgary,
Calgary, Alberta, Canada

Mary Ann McLean

Department of Biology, Indiana State University, Terre Haute, Indiana, U.S.A.

Stefan Scheu

Institute of Zoology, Darmstadt University of Technology, Darmstadt, Germany

CONTENTS

Effects of Channeling, Comminution, and Mixing .......................................................................242
Effects of Earthworm Grazing, Gut Transit, and Casts on Soil Organisms.................................244
Roles of the Soil Biota in Development of Forest Humus Forms ...............................................248
Experimental Approaches to Interactions......................................................................................249
Laboratory Studies of Interactions .........................................................................................249
Field Studies of Interactions...................................................................................................250
Impacts of Earthworm Invasions of Two Montane Forests ..........................................................251
Mode of Invasion of North American Forest Soils by European Earthworms .....................251
Changes in Soil Structure by Colonizing Earthworms ..........................................................251
Changes in Soil Biota Caused by Colonizing Earthworms ...................................................252
Soil Microorganisms .....................................................................................................252
Soil Fauna......................................................................................................................253
Changes in Ecosystem Processes and Plant Growth Caused by Earthworms ......................254
References ......................................................................................................................................254

Interactions of the soil fauna both between different groups of invertebrates and, particularly, with
soil microorganisms are considered important in affecting soil processes (e.g., organic matter
decomposition and nutrient cycling) and in influencing the community composition of various
groups of the soil biota (Seastedt 1984; Visser 1985). The ways in which these functional and
community structure effects are achieved are by (1) comminution of and channeling in organic
debris and mixing of organic debris and mineral soil, (2) grazing on microbial tissues, and (3)
dispersal of microbial propagules (Visser 1985).

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