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Using models to guide field experiments : a priori predictions for the CO2 response of a nutrient- and water-limited native Eucalypt woodland

Medlyn, Belinda E.; De Kauwe, Martin G.; Zaehle, Sönke; Walker, Anthony P.; Duursma, Remko A.; Luus, Kristina; Mishurov, Mikhail LU ; Pak, Bernard; Smith, Benjamin LU and Wang, Ying Ping, et al. (2016) In Global Change Biology 22(8). p.2834-2851
Abstract

The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they... (More)

The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutrient uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.

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publication status
published
subject
keywords
carbon dioxide, drought, ecosystem model, Eucalyptus tereticornis, phosphorus
in
Global Change Biology
volume
22
issue
8
pages
18 pages
publisher
Wiley-Blackwell
external identifiers
  • pmid:26946185
  • wos:000380016800016
  • scopus:84977641981
ISSN
1354-1013
DOI
10.1111/gcb.13268
language
English
LU publication?
yes
id
c3ec8fba-00c1-49ca-abaa-f62510fbe107 (old id 8856106)
date added to LUP
2016-03-21 08:48:49
date last changed
2017-08-13 03:08:44
@article{c3ec8fba-00c1-49ca-abaa-f62510fbe107,
  abstract     = {<p>The response of terrestrial ecosystems to rising atmospheric CO<sub>2</sub> concentration (C<sub>a</sub>), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO<sub>2</sub> Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated C<sub>a</sub> ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutrient uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.</p>},
  author       = {Medlyn, Belinda E. and De Kauwe, Martin G. and Zaehle, Sönke and Walker, Anthony P. and Duursma, Remko A. and Luus, Kristina and Mishurov, Mikhail and Pak, Bernard and Smith, Benjamin and Wang, Ying Ping and Yang, Xiaojuan and Crous, Kristine Y. and Drake, John E. and Gimeno, Teresa E. and Macdonald, Catriona A. and Norby, Richard J. and Power, Sally A. and Tjoelker, Mark G. and Ellsworth, David S.},
  issn         = {1354-1013},
  keyword      = {carbon dioxide,drought,ecosystem model,Eucalyptus tereticornis,phosphorus},
  language     = {eng},
  month        = {08},
  number       = {8},
  pages        = {2834--2851},
  publisher    = {Wiley-Blackwell},
  series       = {Global Change Biology},
  title        = {Using models to guide field experiments : a priori predictions for the CO<sub>2</sub> response of a nutrient- and water-limited native Eucalypt woodland},
  url          = {http://dx.doi.org/10.1111/gcb.13268},
  volume       = {22},
  year         = {2016},
}