Agriculture Reference
In-Depth Information
landscape-level studies progress, it may become possible to assess the roles of earthworms in
biogeochemical cycles at regional or even global scales.
CONCLUSIONS
There is sufficient field research evidence to suggest that earthworms play a major role in soil
nutrient cycling processes. Research evaluating the effects of earthworms on biogeochemistry is
increasingly interdisciplinary, combining the various aspects of the effects of earthworms on soil
biological, chemical, and physical processes. Researchers active in all aspects of earthworm ecology
can contribute to a better understanding of the role of earthworms in nutrient cycling processes in
both natural and managed ecosystems. However, there continues to be a need for research that
crosses traditional boundaries and includes collaborations with scientists from other disciplines.
The understanding of the effects of earthworms at the ecosystem and landscape scales still lags
behind the many studies at smaller scales. The effects of earthworms on nutrient cycling at the
ecosystem level cannot be fully appreciated unless results are scaled up from short-term, small-
scale studies and unless data are integrated from different levels of the ecological hierarchy or
across temporal and spatial scales.
ACKNOWLEDGMENTS
Mike Allen, Scott Subler, and Joann Whalen provided helpful comments on earlier versions of this
chapter. Many of the ideas presented were developed through interactions with Mike Allen, Clive
Edwards, Dave McCartney, Ben Stinner, and Scott Subler. Clive Edwards reviewed and revised the
manuscript. Our research has been supported by grants from the National Science Foundation
(DEB-9O20461) and the U.S. Department of Agriculture (NRI-9402520).
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