Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests

Holly A. Ewing, Amy Tuininga, Peter M. Groffman, Kathleen C. Weathers, Timothy J. Fahey, Melany C. Fisk, Patrick J. Bohlen, Esteban Suarez

Research output: Contribution to journalArticleResearchpeer-review

8 Citations (Scopus)

Abstract

Invasive exotic earthworms are significantly influencing understory community composition, soil, and ecosystem processes in northern hardwood forests in North America, but their effect on the retention of nitrogen (N) has been inconclusive. We examined this in two northern hardwood forest sites in New York state, USA through a tracer study. In both spring and fall, we added tracer amounts of 15N as nitrate—to simulate atmospheric deposition—with the biologically less active tracer bromide (Br) to areas both with and without large populations of invasive earthworms. Total recovery of 15N was lower in earthworm-invaded plots, largely due to less retention in litter and upper soil horizons. Although the strong relationship between retention in the upper soil horizons and total 15N recovery suggests that earthworm destruction of the forest floor may be one mechanism reducing the capacity for N retention, in some cases the mineral soil in earthworm-invaded plots retained substantial N. Biotic pools, particularly litter and microbial biomass, retained significantly less 15N in earthworm-invaded plots than in their uninvaded counterparts. In plots invaded by earthworms, negative effects of earthworms on trees were revealed through root-uptake assays suggesting somewhat greater plant demand for ammonium in the spring and in lower 15N recovery in maple seedlings the year following tracer addition. Although similar patterns of Br movement across treatments suggested that earthworms had smaller effects on hydrologic tracer movement than expected, they appear to have significant effects on the biological processes that underlie N retention.

Original languageEnglish
Pages (from-to)328-342
Number of pages15
JournalEcosystems
Volume18
Issue number2
DOIs
StatePublished - 1 Jan 2015

Fingerprint

Hardwoods
hardwood forests
nitrogen isotope
earthworms
earthworm
Nitrogen
Soils
nitrogen
Bromides
Recovery
tracer techniques
tracer
Ammonium Compounds
soil horizons
Ecosystems
soil horizon
bromides
Minerals
bromide
Assays

Keywords

  • ammonium
  • earthworms
  • hardwood forest
  • hydrology
  • invasive species
  • microbes
  • nitrate
  • nitrogen retention
  • nutrient cycling
  • soils

Cite this

Ewing, H. A., Tuininga, A., Groffman, P. M., Weathers, K. C., Fahey, T. J., Fisk, M. C., ... Suarez, E. (2015). Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests. Ecosystems, 18(2), 328-342. https://doi.org/10.1007/s10021-014-9831-z
Ewing, Holly A. ; Tuininga, Amy ; Groffman, Peter M. ; Weathers, Kathleen C. ; Fahey, Timothy J. ; Fisk, Melany C. ; Bohlen, Patrick J. ; Suarez, Esteban. / Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests. In: Ecosystems. 2015 ; Vol. 18, No. 2. pp. 328-342.
@article{d45e77e660bc449896af062dc4a5cbb9,
title = "Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests",
abstract = "Invasive exotic earthworms are significantly influencing understory community composition, soil, and ecosystem processes in northern hardwood forests in North America, but their effect on the retention of nitrogen (N) has been inconclusive. We examined this in two northern hardwood forest sites in New York state, USA through a tracer study. In both spring and fall, we added tracer amounts of 15N as nitrate—to simulate atmospheric deposition—with the biologically less active tracer bromide (Br−) to areas both with and without large populations of invasive earthworms. Total recovery of 15N was lower in earthworm-invaded plots, largely due to less retention in litter and upper soil horizons. Although the strong relationship between retention in the upper soil horizons and total 15N recovery suggests that earthworm destruction of the forest floor may be one mechanism reducing the capacity for N retention, in some cases the mineral soil in earthworm-invaded plots retained substantial N. Biotic pools, particularly litter and microbial biomass, retained significantly less 15N in earthworm-invaded plots than in their uninvaded counterparts. In plots invaded by earthworms, negative effects of earthworms on trees were revealed through root-uptake assays suggesting somewhat greater plant demand for ammonium in the spring and in lower 15N recovery in maple seedlings the year following tracer addition. Although similar patterns of Br− movement across treatments suggested that earthworms had smaller effects on hydrologic tracer movement than expected, they appear to have significant effects on the biological processes that underlie N retention.",
keywords = "ammonium, earthworms, hardwood forest, hydrology, invasive species, microbes, nitrate, nitrogen retention, nutrient cycling, soils",
author = "Ewing, {Holly A.} and Amy Tuininga and Groffman, {Peter M.} and Weathers, {Kathleen C.} and Fahey, {Timothy J.} and Fisk, {Melany C.} and Bohlen, {Patrick J.} and Esteban Suarez",
year = "2015",
month = "1",
day = "1",
doi = "10.1007/s10021-014-9831-z",
language = "English",
volume = "18",
pages = "328--342",
journal = "Ecosystems",
issn = "1432-9840",
publisher = "Springer New York",
number = "2",

}

Ewing, HA, Tuininga, A, Groffman, PM, Weathers, KC, Fahey, TJ, Fisk, MC, Bohlen, PJ & Suarez, E 2015, 'Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests', Ecosystems, vol. 18, no. 2, pp. 328-342. https://doi.org/10.1007/s10021-014-9831-z

Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests. / Ewing, Holly A.; Tuininga, Amy; Groffman, Peter M.; Weathers, Kathleen C.; Fahey, Timothy J.; Fisk, Melany C.; Bohlen, Patrick J.; Suarez, Esteban.

In: Ecosystems, Vol. 18, No. 2, 01.01.2015, p. 328-342.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests

AU - Ewing, Holly A.

AU - Tuininga, Amy

AU - Groffman, Peter M.

AU - Weathers, Kathleen C.

AU - Fahey, Timothy J.

AU - Fisk, Melany C.

AU - Bohlen, Patrick J.

AU - Suarez, Esteban

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Invasive exotic earthworms are significantly influencing understory community composition, soil, and ecosystem processes in northern hardwood forests in North America, but their effect on the retention of nitrogen (N) has been inconclusive. We examined this in two northern hardwood forest sites in New York state, USA through a tracer study. In both spring and fall, we added tracer amounts of 15N as nitrate—to simulate atmospheric deposition—with the biologically less active tracer bromide (Br−) to areas both with and without large populations of invasive earthworms. Total recovery of 15N was lower in earthworm-invaded plots, largely due to less retention in litter and upper soil horizons. Although the strong relationship between retention in the upper soil horizons and total 15N recovery suggests that earthworm destruction of the forest floor may be one mechanism reducing the capacity for N retention, in some cases the mineral soil in earthworm-invaded plots retained substantial N. Biotic pools, particularly litter and microbial biomass, retained significantly less 15N in earthworm-invaded plots than in their uninvaded counterparts. In plots invaded by earthworms, negative effects of earthworms on trees were revealed through root-uptake assays suggesting somewhat greater plant demand for ammonium in the spring and in lower 15N recovery in maple seedlings the year following tracer addition. Although similar patterns of Br− movement across treatments suggested that earthworms had smaller effects on hydrologic tracer movement than expected, they appear to have significant effects on the biological processes that underlie N retention.

AB - Invasive exotic earthworms are significantly influencing understory community composition, soil, and ecosystem processes in northern hardwood forests in North America, but their effect on the retention of nitrogen (N) has been inconclusive. We examined this in two northern hardwood forest sites in New York state, USA through a tracer study. In both spring and fall, we added tracer amounts of 15N as nitrate—to simulate atmospheric deposition—with the biologically less active tracer bromide (Br−) to areas both with and without large populations of invasive earthworms. Total recovery of 15N was lower in earthworm-invaded plots, largely due to less retention in litter and upper soil horizons. Although the strong relationship between retention in the upper soil horizons and total 15N recovery suggests that earthworm destruction of the forest floor may be one mechanism reducing the capacity for N retention, in some cases the mineral soil in earthworm-invaded plots retained substantial N. Biotic pools, particularly litter and microbial biomass, retained significantly less 15N in earthworm-invaded plots than in their uninvaded counterparts. In plots invaded by earthworms, negative effects of earthworms on trees were revealed through root-uptake assays suggesting somewhat greater plant demand for ammonium in the spring and in lower 15N recovery in maple seedlings the year following tracer addition. Although similar patterns of Br− movement across treatments suggested that earthworms had smaller effects on hydrologic tracer movement than expected, they appear to have significant effects on the biological processes that underlie N retention.

KW - ammonium

KW - earthworms

KW - hardwood forest

KW - hydrology

KW - invasive species

KW - microbes

KW - nitrate

KW - nitrogen retention

KW - nutrient cycling

KW - soils

UR - http://www.scopus.com/inward/record.url?scp=84925496054&partnerID=8YFLogxK

U2 - 10.1007/s10021-014-9831-z

DO - 10.1007/s10021-014-9831-z

M3 - Article

VL - 18

SP - 328

EP - 342

JO - Ecosystems

JF - Ecosystems

SN - 1432-9840

IS - 2

ER -