Modelling climate change responses in tropical forests

Similar productivity estimates across five models, but different mechanisms and responses

L. Rowland, A. Harper, B. O. Christoffersen, D. R. Galbraith, H. M A Imbuzeiro, T. L. Powell, C. Doughty, N. M. Levine, Y. Malhi, Scott Saleska, P. R. Moorcroft, P. Meir, M. Williams

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Accurately predicting the response of Amazonia to climate change is important for predicting climate change across the globe. Changes in multiple climatic factors simultaneously result in complex non-linear ecosystem responses, which are difficult to predict using vegetation models. Using leaf- and canopy-scale observations, this study evaluated the capability of five vegetation models (Community Land Model version 3.5 coupled to the Dynamic Global Vegetation model - CLM3.5-DGVM; Ecosystem Demography model version 2 - ED2; the Joint UK Land Environment Simulator version 2.1 - JULES; Simple Biosphere model version 3 - SiB3; and the soil-plant-atmosphere model - SPA) to simulate the responses of leaf- and canopy-scale productivity to changes in temperature and drought in an Amazonian forest. <br><br> The models did not agree as to whether gross primary productivity (GPP) was more sensitive to changes in temperature or precipitation, but all the models were consistent with the prediction that GPP would be higher if tropical forests were 5 °C cooler than current ambient temperatures. There was greater model-data consistency in the response of net ecosystem exchange (NEE) to changes in temperature than in the response to temperature by net photosynthesis (<i>A</i>n), stomatal conductance (<i>g</i>s) and leaf area index (LAI). Modelled canopy-scale fluxes are calculated by scaling leaf-scale fluxes using LAI. At the leaf-scale, the models did not agree on the temperature or magnitude of the optimum points of <i>A</i>n, <i>V</i>cmax or <i>g</i>s, and model variation in these parameters was compensated for by variations in the absolute magnitude of simulated LAI and how it altered with temperature. <br><br> Across the models, there was, however, consistency in two leaf-scale responses: (1) change in <i>A</i>n with temperature was more closely linked to stomatal behaviour than biochemical processes; and (2) intrinsic water use efficiency (IWUE) increased with temperature, especially when combined with drought. These results suggest that even up to fairly extreme temperature increases from ambient levels (+6 °C), simulated photosynthesis becomes increasingly sensitive to <i>g</i>s and remains less sensitive to biochemical changes. To improve the reliability of simulations of the response of Amazonian rainforest to climate change, the mechanistic underpinnings of vegetation models need to be validated at both leaf- and canopy-scales to improve accuracy and consistency in the quantification of processes within and across an ecosystem.

Original languageEnglish (US)
Pages (from-to)1097-1110
Number of pages14
JournalGeoscientific Model Development
Volume8
Issue number4
DOIs
StatePublished - Apr 21 2015

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Climate Change
Climate change
tropical forest
Productivity
productivity
climate change
Modeling
Estimate
modeling
Leaves
Vegetation
Leaf Area Index
Ecosystem
temperature
Ecosystems
Model
Temperature
canopy
leaf area index
Drought

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Modeling and Simulation

Cite this

Rowland, L., Harper, A., Christoffersen, B. O., Galbraith, D. R., Imbuzeiro, H. M. A., Powell, T. L., ... Williams, M. (2015). Modelling climate change responses in tropical forests: Similar productivity estimates across five models, but different mechanisms and responses. Geoscientific Model Development, 8(4), 1097-1110. https://doi.org/10.5194/gmd-8-1097-2015

Modelling climate change responses in tropical forests : Similar productivity estimates across five models, but different mechanisms and responses. / Rowland, L.; Harper, A.; Christoffersen, B. O.; Galbraith, D. R.; Imbuzeiro, H. M A; Powell, T. L.; Doughty, C.; Levine, N. M.; Malhi, Y.; Saleska, Scott; Moorcroft, P. R.; Meir, P.; Williams, M.

In: Geoscientific Model Development, Vol. 8, No. 4, 21.04.2015, p. 1097-1110.

Research output: Contribution to journalArticle

Rowland, L, Harper, A, Christoffersen, BO, Galbraith, DR, Imbuzeiro, HMA, Powell, TL, Doughty, C, Levine, NM, Malhi, Y, Saleska, S, Moorcroft, PR, Meir, P & Williams, M 2015, 'Modelling climate change responses in tropical forests: Similar productivity estimates across five models, but different mechanisms and responses', Geoscientific Model Development, vol. 8, no. 4, pp. 1097-1110. https://doi.org/10.5194/gmd-8-1097-2015
Rowland, L. ; Harper, A. ; Christoffersen, B. O. ; Galbraith, D. R. ; Imbuzeiro, H. M A ; Powell, T. L. ; Doughty, C. ; Levine, N. M. ; Malhi, Y. ; Saleska, Scott ; Moorcroft, P. R. ; Meir, P. ; Williams, M. / Modelling climate change responses in tropical forests : Similar productivity estimates across five models, but different mechanisms and responses. In: Geoscientific Model Development. 2015 ; Vol. 8, No. 4. pp. 1097-1110.
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