Ecosystems

, Volume 7, Issue 1, pp 28–44

Effects of Exotic Earthworms on Soil Phosphorus Cycling in Two Broadleaf Temperate Forests

  • Esteban R. Suárez
  • Derek M. Pelletier
  • Timothy J. Fahey
  • Peter M. Groffman
  • Patrick J. Bohlen
  • Melany C. Fisk
Article

Abstract

We compared the biogeochemical cycling of phosphorus (P) in northern hardwood forest plots invaded by exotic earthworms versus adjacent uninvaded reference plots. In three of the six pairs of plots, earthworm invasion resulted in significantly more total P in the upper 12 cm of soil. The finding of increased amounts of unavailable and occluded inorganic P forms in the invaded plots suggests that earthworm activity mobilized unweathered soil particles from deeper layers of the soil, increasing the stocks of total P in surface soils. In two pairs of plots, the earthworm-invaded soils had less total P than the reference soils. In these plots, earthworm activity resulted in augmented rates of P cycling and alteration of the physical structure of the soil that increased loss of P in leaching water, reducing the total amount of P. We hypothesize that the different effects of earthworm invasion on the soil P cycle result from unique characteristics of the ecological groups of earthworms dominating each site. The invaded plots with increased total P were dominated by the anecic species Lumbricus terrestris, a large earthworm that constructs deep, vertical burrows and is effective at moving soil materials from and to deeper layers of the profile. In contrast, the earthworm-invaded plots where the total P in the surface soil decreased were dominated by the epi-endogeic species L. rubellus, which feeds and lives in the upper organic layers of the soil. In these plots, earthworms significantly increased the amount of readily exchangeable P in the soil, increasing the loss of this element in leaching water.

Keywords

exotic earthworms invasions phosphorus cycle northern hardwood forests 

Copyright information

© Springer-Verlag New York, Inc. 2004

Authors and Affiliations

  • Esteban R. Suárez
    • 1
  • Derek M. Pelletier
    • 1
  • Timothy J. Fahey
    • 1
  • Peter M. Groffman
    • 2
  • Patrick J. Bohlen
    • 3
  • Melany C. Fisk
    • 1
    • 4
  1. 1.Department of Natural ResourcesCornell University, Ithaca, New York 14853USA
  2. 2.Institute of Ecosystem Studies, Box AB, Millbrook, New York 12545USA
  3. 3.Archbold Biological Station, Lake Placid, Florida 33852USA
  4. 4.Department of Biology, Appalachian State University, Boone, North Carolina 28608-2027USA

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