Nitrogen deposition and greenhouse gas emissions from grasslands: Uncertainties and future directions

Nuria Gomez-Casanovas, Tara W. Hudiburg, Carl Bernacchi, William J. Parton, Evan H Delucia

Research output: Contribution to journalArticle

Abstract

Increases in atmospheric nitrogen deposition (Ndep) can strongly affect the greenhouse gas (GHG; CO2, CH4, and N2O) sink capacity of grasslands as well as other terrestrial ecosystems. Robust predictions of the net GHG sink strength of grasslands depend on how experimental N loads compare to projected Ndep rates, and how accurately the relationship between GHG fluxes and Ndep is characterized. A literature review revealed that the vast majority of experimental N loads were higher than levels these ecosystems are predicted to experience in the future. Using a process-based biogeochemical model, we predicted that low levels of Ndep either enhanced or reduced the net GHG sink strength of most grasslands, but as experimental N loads continued to increase, grasslands transitioned to a N saturation-decline stage, where the sensitivity of GHG exchange to further increases in Ndep declined. Most published studies represented treatments well into the N saturation-decline stage. Our model results predict that the responses of GHG fluxes to N are highly nonlinear and that the N saturation thresholds for GHGs varied greatly among grasslands and with fire management. We predict that during the 21st century some grasslands will be in the N limitation stage where others will transition into the N saturation-decline stage. The linear relationship between GHG sink strength and N load assumed by most studies can overestimate or underestimate predictions of the net GHG sink strength of grasslands depending on their N baseline status. The next generation of global change experiments should be designed at multiple N loads consistent with future Ndep rates to improve our empirical understanding and predictive ability. Copyright

Original languageEnglish (US)
Pages (from-to)1348-1360
Number of pages13
JournalGlobal Change Biology
Volume22
Issue number4
DOIs
StatePublished - Apr 1 2016

Fingerprint

Gas emissions
Greenhouse gases
greenhouse gas
Nitrogen
grassland
nitrogen
saturation
Deposition rates
Ecosystems
Fluxes
fire management
twenty first century
prediction
Uncertainty
Direction compound
literature review
terrestrial ecosystem
Fires
global change
well

Keywords

  • CH
  • Grassland
  • Methane
  • NO
  • Net ecosystem CO exchange
  • Net ecosystem productivity
  • Nitrogen deposition
  • Nitrogen fertilization
  • Nitrous oxide
  • Uncertainty

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Ecology
  • Environmental Science(all)

Cite this

Nitrogen deposition and greenhouse gas emissions from grasslands : Uncertainties and future directions. / Gomez-Casanovas, Nuria; Hudiburg, Tara W.; Bernacchi, Carl; Parton, William J.; Delucia, Evan H.

In: Global Change Biology, Vol. 22, No. 4, 01.04.2016, p. 1348-1360.

Research output: Contribution to journalArticle

Gomez-Casanovas, Nuria ; Hudiburg, Tara W. ; Bernacchi, Carl ; Parton, William J. ; Delucia, Evan H. / Nitrogen deposition and greenhouse gas emissions from grasslands : Uncertainties and future directions. In: Global Change Biology. 2016 ; Vol. 22, No. 4. pp. 1348-1360.
@article{6208a6fc6760442caec1763de1554cbd,
title = "Nitrogen deposition and greenhouse gas emissions from grasslands: Uncertainties and future directions",
abstract = "Increases in atmospheric nitrogen deposition (Ndep) can strongly affect the greenhouse gas (GHG; CO2, CH4, and N2O) sink capacity of grasslands as well as other terrestrial ecosystems. Robust predictions of the net GHG sink strength of grasslands depend on how experimental N loads compare to projected Ndep rates, and how accurately the relationship between GHG fluxes and Ndep is characterized. A literature review revealed that the vast majority of experimental N loads were higher than levels these ecosystems are predicted to experience in the future. Using a process-based biogeochemical model, we predicted that low levels of Ndep either enhanced or reduced the net GHG sink strength of most grasslands, but as experimental N loads continued to increase, grasslands transitioned to a N saturation-decline stage, where the sensitivity of GHG exchange to further increases in Ndep declined. Most published studies represented treatments well into the N saturation-decline stage. Our model results predict that the responses of GHG fluxes to N are highly nonlinear and that the N saturation thresholds for GHGs varied greatly among grasslands and with fire management. We predict that during the 21st century some grasslands will be in the N limitation stage where others will transition into the N saturation-decline stage. The linear relationship between GHG sink strength and N load assumed by most studies can overestimate or underestimate predictions of the net GHG sink strength of grasslands depending on their N baseline status. The next generation of global change experiments should be designed at multiple N loads consistent with future Ndep rates to improve our empirical understanding and predictive ability. Copyright",
keywords = "CH, Grassland, Methane, NO, Net ecosystem CO exchange, Net ecosystem productivity, Nitrogen deposition, Nitrogen fertilization, Nitrous oxide, Uncertainty",
author = "Nuria Gomez-Casanovas and Hudiburg, {Tara W.} and Carl Bernacchi and Parton, {William J.} and Delucia, {Evan H}",
year = "2016",
month = "4",
day = "1",
doi = "10.1111/gcb.13187",
language = "English (US)",
volume = "22",
pages = "1348--1360",
journal = "Global Change Biology",
issn = "1354-1013",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Nitrogen deposition and greenhouse gas emissions from grasslands

T2 - Uncertainties and future directions

AU - Gomez-Casanovas, Nuria

AU - Hudiburg, Tara W.

AU - Bernacchi, Carl

AU - Parton, William J.

AU - Delucia, Evan H

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Increases in atmospheric nitrogen deposition (Ndep) can strongly affect the greenhouse gas (GHG; CO2, CH4, and N2O) sink capacity of grasslands as well as other terrestrial ecosystems. Robust predictions of the net GHG sink strength of grasslands depend on how experimental N loads compare to projected Ndep rates, and how accurately the relationship between GHG fluxes and Ndep is characterized. A literature review revealed that the vast majority of experimental N loads were higher than levels these ecosystems are predicted to experience in the future. Using a process-based biogeochemical model, we predicted that low levels of Ndep either enhanced or reduced the net GHG sink strength of most grasslands, but as experimental N loads continued to increase, grasslands transitioned to a N saturation-decline stage, where the sensitivity of GHG exchange to further increases in Ndep declined. Most published studies represented treatments well into the N saturation-decline stage. Our model results predict that the responses of GHG fluxes to N are highly nonlinear and that the N saturation thresholds for GHGs varied greatly among grasslands and with fire management. We predict that during the 21st century some grasslands will be in the N limitation stage where others will transition into the N saturation-decline stage. The linear relationship between GHG sink strength and N load assumed by most studies can overestimate or underestimate predictions of the net GHG sink strength of grasslands depending on their N baseline status. The next generation of global change experiments should be designed at multiple N loads consistent with future Ndep rates to improve our empirical understanding and predictive ability. Copyright

AB - Increases in atmospheric nitrogen deposition (Ndep) can strongly affect the greenhouse gas (GHG; CO2, CH4, and N2O) sink capacity of grasslands as well as other terrestrial ecosystems. Robust predictions of the net GHG sink strength of grasslands depend on how experimental N loads compare to projected Ndep rates, and how accurately the relationship between GHG fluxes and Ndep is characterized. A literature review revealed that the vast majority of experimental N loads were higher than levels these ecosystems are predicted to experience in the future. Using a process-based biogeochemical model, we predicted that low levels of Ndep either enhanced or reduced the net GHG sink strength of most grasslands, but as experimental N loads continued to increase, grasslands transitioned to a N saturation-decline stage, where the sensitivity of GHG exchange to further increases in Ndep declined. Most published studies represented treatments well into the N saturation-decline stage. Our model results predict that the responses of GHG fluxes to N are highly nonlinear and that the N saturation thresholds for GHGs varied greatly among grasslands and with fire management. We predict that during the 21st century some grasslands will be in the N limitation stage where others will transition into the N saturation-decline stage. The linear relationship between GHG sink strength and N load assumed by most studies can overestimate or underestimate predictions of the net GHG sink strength of grasslands depending on their N baseline status. The next generation of global change experiments should be designed at multiple N loads consistent with future Ndep rates to improve our empirical understanding and predictive ability. Copyright

KW - CH

KW - Grassland

KW - Methane

KW - NO

KW - Net ecosystem CO exchange

KW - Net ecosystem productivity

KW - Nitrogen deposition

KW - Nitrogen fertilization

KW - Nitrous oxide

KW - Uncertainty

UR - http://www.scopus.com/inward/record.url?scp=84959113514&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84959113514&partnerID=8YFLogxK

U2 - 10.1111/gcb.13187

DO - 10.1111/gcb.13187

M3 - Article

C2 - 26661794

AN - SCOPUS:84959113514

VL - 22

SP - 1348

EP - 1360

JO - Global Change Biology

JF - Global Change Biology

SN - 1354-1013

IS - 4

ER -