De Kauwe, Martin G; Lin, Yan-Shih; Wright, Ian J; Medlyn, Belinda E; Crous, Kristine Y; Ellsworth, David S; Maire, Vincent; Prentice, I Colin; Atkin, Owen K; Rogers, Alistair; Niinemets, Ulo; Serbin, Shawn P; Meir, Patrick; Uddling, Johan; Togashi, Henrique F; Tarvainen, Lasse; Weerasinghe, Lasantha K; Evans, Bradley J; Ishida, F Yoko; Domingues, Tomas F

Author(s)

De Kauwe, Martin G

Lin, Yan-Shih

Wright, Ian J

Medlyn, Belinda E

Crous, Kristine Y

Ellsworth, David S

Maire, Vincent

Prentice, I Colin

Atkin, Owen K

Rogers, Alistair

Niinemets, Ulo

Serbin, Shawn P

Meir, Patrick

Uddling, Johan

Togashi, Henrique F

Tarvainen, Lasse

Weerasinghe, Lasantha K

Evans, Bradley J

Ishida, F Yoko

Domingues, Tomas F

Publication Date

2016-05

Abstract

• Simulations of photosynthesis by terrestrial biosphere models typically need a specification of the maximum carboxylation rate (Vcmax). Estimating this parameter using A–Ci curves (net photosynthesis, A, vs intercellular CO2 concentration, Ci ) is laborious, which limits availability of Vcmax data. However, many multispecies field datasets include net photosynthetic rate at saturating irradiance and at ambient atmospheric CO2 concentration (Asat) measurements, from which Vcmax can be extracted using a ‘one-point method’. • We used a global dataset of A–Ci curves (564 species from 46 field sites, covering a range of plant functional types) to test the validity of an alternative approach to estimate Vcmax from Asat via this ‘one-point method’. • If leaf respiration during the day (Rday) is known exactly, Vcmax can be estimated with an r 2 value of 0.98 and a root-mean-squared error (RMSE) of 8.19 lmol m-2 s-1 . However, Rday typically must be estimated. Estimating Rday as 1.5% of Vcmax, we found that Vcmax could be estimated with an r 2 of 0.95 and an RMSE of 17.1 lmol m-2 s-1 . • The one-point method provides a robust means to expand current databases of fieldmeasured Vcmax, giving new potential to improve vegetation models and quantify the environmental drivers of Vcmax variation.

Citation

New Phytologist, 210(3), p. 1130-1144

ISSN

1469-8137

0028-646X

Link

https://hdl.handle.net/1959.11/58865

Publisher

Wiley-Blackwell Publishing Ltd

Title

A test of the 'one-point method' for estimating maximum carboxylation capacity from field-measured, light-saturated photosynthesis

Type of document

Journal Article

Entity Type

Publication

Author(s)	De Kauwe, Martin G Lin, Yan-Shih Wright, Ian J Medlyn, Belinda E Crous, Kristine Y Ellsworth, David S Maire, Vincent Prentice, I Colin Atkin, Owen K Rogers, Alistair Niinemets, Ulo Serbin, Shawn P Meir, Patrick Uddling, Johan Togashi, Henrique F Tarvainen, Lasse Weerasinghe, Lasantha K Evans, Bradley J Ishida, F Yoko Domingues, Tomas F
Publication Date	2016-05
Abstract	<p> • Simulations of photosynthesis by terrestrial biosphere models typically need a specification of the maximum carboxylation rate (<i>V</i><sub>cmax</sub>). Estimating this parameter using <i>A–C</i><sub>i</sub> curves (net photosynthesis, <i>A</i>, vs intercellular CO<sub>2</sub> concentration, <i>C<sub>i</sub></i> ) is laborious, which limits availability of <i>V</i><sub>cmax</sub> data. However, many multispecies field datasets include net photosynthetic rate at saturating irradiance and at ambient atmospheric CO<sub>2</sub> concentration (A<sub>sat</sub>) measurements, from which <i>V</i><sub>cmax</sub> can be extracted using a ‘one-point method’.</p> <p>• We used a global dataset of <i>A–C</i><sub>i</sub> curves (564 species from 46 field sites, covering a range of plant functional types) to test the validity of an alternative approach to estimate <i>V</i><sub>cmax</sub> from A<sub>sat</sub> via this ‘one-point method’.</p> <p>• If leaf respiration during the day (<i>R<sub>day</sub></i>) is known exactly, <i>V</i><sub>cmax</sub> can be estimated with an <i>r <sup>2</sup></i> value of 0.98 and a root-mean-squared error (RMSE) of 8.19 lmol m<sup>-2</sup> s<sup>-1</sup> . However, <i>R<sub>day</sub></i> typically must be estimated. Estimating <i>R<sub>day</sub></i> as 1.5% of <i>V</i><sub>cmax</sub>, we found that <i>V</i><sub>cmax</sub> could be estimated with an <i>r <sup>2</sup></i> of 0.95 and an RMSE of 17.1 lmol m<sup>-2</sup> s<sup>-1</sup> .</p> <p>• The one-point method provides a robust means to expand current databases of fieldmeasured <i>V</i><sub>cmax</sub>, giving new potential to improve vegetation models and quantify the environmental drivers of <i>V</i><sub>cmax</sub> variation. </p>
Citation	New Phytologist, 210(3), p. 1130-1144
ISSN	1469-8137 0028-646X
Link	https://hdl.handle.net/1959.11/58865
Publisher	Wiley-Blackwell Publishing Ltd
Title	A test of the 'one-point method' for estimating maximum carboxylation capacity from field-measured, light-saturated photosynthesis
Type of document	Journal Article
Entity Type	Publication

A test of the 'one-point method' for estimating maximum carboxylation capacity from field-measured, light-saturated photosynthesis

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