Wang, Han; Prentice, I Colin; Keenan, Trevor F; Davis, Tyler W; Wright, Ian J; Cornwell, William K; Evans, Bradley J; Peng, Changhui

Author(s)

Wang, Han

Prentice, I Colin

Keenan, Trevor F

Davis, Tyler W

Wright, Ian J

Cornwell, William K

Evans, Bradley J

Peng, Changhui

Publication Date

2017-09-04

Abstract

Gross primary production (GPP)—the uptake of carbon dioxide (CO2) by leaves, and its conversion to sugars by photosynthesis—is the basis for life on land. Earth System Models (ESMs) incorporating the interactions of land ecosystems and climate are used to predict the future of the terrestrial sink for anthropogenic CO2 1 . ESMs require accurate representation of GPP. However, current ESMs disagree on how GPP responds to environmental variations1,2, suggesting a need for a more robust theoretical framework for modelling3,4. Here, we focus on a key quantity for GPP, the ratio of leaf internal to external CO2 (χ). χ is tightly regulated and depends on environmental conditions, but is represented empirically and incompletely in today’s models. We show that a simple evolutionary optimality hypothesis5,6 predicts specific quantitative dependencies of χ on temperature, vapour pressure deficit and elevation; and that these same dependencies emerge from an independent analysis of empirical χ values, derived from a worldwide dataset of >3,500 leaf stable carbon isotope measurements. A single global equation embodying these relationships then unifies the empirical light-use efficiency model7 with the standard model of C3 photosynthesis8, and successfully predicts GPP measured at eddy-covariance flux sites. This success is notable given the equation’s simplicity and broad applicability across biomes and plant functional types. It provides a theoretical underpinning for the analysis of plant functional coordination across species and emergent properties of ecosystems, and a potential basis for the reformulation of the controls of GPP in next-generation ESMs.

Citation

Nature Plants, 3(9), p. 734-741

ISSN

2055-0278

2055-026X

Link

https://hdl.handle.net/1959.11/58863

Publisher

Nature Publishing Group

Title

Towards a universal model for carbon dioxide uptake by plants

Type of document

Journal Article

Entity Type

Publication

Author(s)	Wang, Han Prentice, I Colin Keenan, Trevor F Davis, Tyler W Wright, Ian J Cornwell, William K Evans, Bradley J Peng, Changhui
Publication Date	2017-09-04
Abstract	<p>Gross primary production (GPP)—the uptake of carbon dioxide (CO<sub>2</sub>) by leaves, and its conversion to sugars by photosynthesis—is the basis for life on land. Earth System Models (ESMs) incorporating the interactions of land ecosystems and climate are used to predict the future of the terrestrial sink for anthropogenic CO<sub>2</sub> 1 . ESMs require accurate representation of GPP. However, current ESMs disagree on how GPP responds to environmental variations1,2, suggesting a need for a more robust theoretical framework for modelling3,4. Here, we focus on a key quantity for GPP, the ratio of leaf internal to external CO<sub>2</sub> (<i>χ</i>). <i>χ</i> is tightly regulated and depends on environmental conditions, but is represented empirically and incompletely in today’s models. We show that a simple evolutionary optimality hypothesis5,6 predicts specific quantitative dependencies of <i>χ</i> on temperature, vapour pressure deficit and elevation; and that these same dependencies emerge from an independent analysis of empirical <i>χ</i> values, derived from a worldwide dataset of >3,500 leaf stable carbon isotope measurements. A single global equation embodying these relationships then unifies the empirical light-use efficiency model7 with the standard model of C<sub>3</sub> photosynthesis8, and successfully predicts GPP measured at eddy-covariance flux sites. This success is notable given the equation’s simplicity and broad applicability across biomes and plant functional types. It provides a theoretical underpinning for the analysis of plant functional coordination across species and emergent properties of ecosystems, and a potential basis for the reformulation of the controls of GPP in next-generation ESMs.</p>
Citation	Nature Plants, 3(9), p. 734-741
ISSN	2055-0278 2055-026X
Link	https://hdl.handle.net/1959.11/58863
Publisher	Nature Publishing Group
Title	Towards a universal model for carbon dioxide uptake by plants
Type of document	Journal Article
Entity Type	Publication

Towards a universal model for carbon dioxide uptake by plants

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