TY - JOUR
T1 - Reliable estimation of biochemical parameters from C3 leaf photosynthesis-intercellular carbon dioxide response curves
AU - Gu, Lianhong
AU - Pallardy, Stephen G.
AU - Tu, Kevin
AU - Law, Beverly E.
AU - Wullschleger, Stan D.
PY - 2010/11
Y1 - 2010/11
N2 - The Farquhar-von Caemmerer-Berry (FvCB) model of photosynthesis is a change-point model and structurally overparameterized for interpreting the response of leaf net assimilation (A) to intercellular CO2 concentration (Ci). The use of conventional fitting methods may lead not only to incorrect parameters but also several previously unrecognized consequences. For example, the relationships between key parameters may be fixed computationally and certain fits may be produced in which the estimated parameters result in contradictory identification of the limitation states of the data. Here we describe a new approach that is better suited to the FvCB model characteristics. It consists of four main steps: (1) enumeration of all possible distributions of limitation states; (2) fitting the FvCB model to each limitation state distribution by minimizing a distribution-wise cost function that has desirable properties for parameter estimation; (3) identification and correction of inadmissible fits; and (4) selection of the best fit from all possible limitation state distributions. The new approach implemented theoretical parameter resolvability with numerical procedures that maximally use the information content of the data. It was tested with model simulations, sampled A/Ci curves, and chlorophyll fluorescence measurements of different tree species. The new approach is accessible through the automated website leafweb.ornl.gov.
AB - The Farquhar-von Caemmerer-Berry (FvCB) model of photosynthesis is a change-point model and structurally overparameterized for interpreting the response of leaf net assimilation (A) to intercellular CO2 concentration (Ci). The use of conventional fitting methods may lead not only to incorrect parameters but also several previously unrecognized consequences. For example, the relationships between key parameters may be fixed computationally and certain fits may be produced in which the estimated parameters result in contradictory identification of the limitation states of the data. Here we describe a new approach that is better suited to the FvCB model characteristics. It consists of four main steps: (1) enumeration of all possible distributions of limitation states; (2) fitting the FvCB model to each limitation state distribution by minimizing a distribution-wise cost function that has desirable properties for parameter estimation; (3) identification and correction of inadmissible fits; and (4) selection of the best fit from all possible limitation state distributions. The new approach implemented theoretical parameter resolvability with numerical procedures that maximally use the information content of the data. It was tested with model simulations, sampled A/Ci curves, and chlorophyll fluorescence measurements of different tree species. The new approach is accessible through the automated website leafweb.ornl.gov.
KW - A/Ci curve fitting
KW - Change-point model
KW - Leaf gas exchange measurements
KW - Leafweb
KW - Photosynthesis
UR - http://www.scopus.com/inward/record.url?scp=77958536980&partnerID=8YFLogxK
U2 - 10.1111/j.1365-3040.2010.02192.x
DO - 10.1111/j.1365-3040.2010.02192.x
M3 - Article
C2 - 20561254
AN - SCOPUS:77958536980
SN - 0140-7791
VL - 33
SP - 1852
EP - 1874
JO - Plant Cell and Environment
JF - Plant Cell and Environment
IS - 11
ER -