title: Community-specific impacts of exotic earthworm invasions on soil carbon dynamics in a sandy temperate forest.
abstract: Exotic earthworm introductions can alter above- and belowground properties of temperate forests, but the net impacts on forest soil carbon (C) dynamics are poorly understood. We used a mesocosm experiment to examine the impacts of earthworm species belonging to three different ecological groups (Lumbricus terrestris [anecic], Aporrectodea trapezoides [endogeic], and Eisenia fetida [epigeic]) on C distributions and storage in reconstructed soil profiles from a sandy temperate forest soil by measuring CO2 and dissolved organic carbon (DOC) losses, litter C incorporation into soil, and soil C storage with monospecific and species combinations as treatments. Soil CO2 loss was 30% greater from the Endogeic x Epigeic treatment than from controls (no earthworms) over the first 45 days; CO2 losses from monospecific treatments did not differ from controls. DOC losses were three orders of magnitude lower than CO2 losses, and were similar across earthworm community treatments. Communities with the anecic species accelerated litter C mass loss by 31-39% with differential mass loss of litter types (Acer rubrum > Populus grandidentata > Fagus grandifolia > Quercus rubra > or = Pinus strobus) indicative of leaf litter preference. Burrow system volume, continuity, and size distribution differed across earthworm treatments but did not affect cumulative CO2 or DOC losses. However, burrow system structure controlled vertical C redistribution by mediating the contributions of leaf litter to A-horizon C and N pools, as indicated by strong correlations between (1) subsurface vertical burrows made by anecic species, and accelerated leaf litter mass losses (with the exception of P. strobus); and (2) dense burrow networks in the A-horizon and the C and N properties of these pools. Final soil C storage was slightly lower in earthworm treatments, indicating that increased leaf litter C inputs into soil were more than offset by losses as CO2 and DOC across earthworm community treatments.
authors.affiliation: Department of Ecology and Evolutionary Biology, 2019 Kraus Natural Science Building, 830 North University Avenue, University of Michigan, Ann Arbor, Michigan 48109, USA. jcrumsey@umich.edu
authors.forename: Jasmine M
authors.initials: JM
authors.lastname: Crumsey
authors.affiliation: Department of Ecology and Evolutionary Biology, 2019 Kraus Natural Science Building, 830 North University Avenue, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Le Moine
authors.affiliation: INRA, UR 1115 Plantes et Systèmes Horticoles, 84914 Avignon Cedex 09, France.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Capowiez
authors.affiliation: Department of Radiology, 1500 East Medical Center Drive, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Mitchell M
authors.initials: MM
authors.lastname: Goodsitt
authors.affiliation: Department of Radiology, 1500 East Medical Center Drive, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Larson
authors.affiliation: Department of Ecology and Evolutionary Biology, 2019 Kraus Natural Science Building, 830 North University Avenue, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: George W
authors.initials: GW
authors.lastname: Kling
authors.affiliation: Department of Ecology and Evolutionary Biology, 2019 Kraus Natural Science Building, 830 North University Avenue, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Knute J
authors.initials: KJ
authors.lastname: Nadelhoffer
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry* / Q000378:metabolism; D017753:Ecosystem; D058865:Introduced Species; D009835:Oligochaeta / Q000145:classification* / Q000502:physiology*; D012822:Silicon Dioxide; D012987:Soil / Q000737:chemistry*; D013997:Time Factors; D014197:Trees
chemical_list: D012987:Soil; D002244:Carbon; D012822:Silicon Dioxide