Software for the Analysis of Leaf Gas Exchange Data

Richard Parsons r.parsons at
Tue Jan 27 12:13:37 EST 1998

People who measure aspects of leaf photosynthesis by constructing
response curves of net assimilation to light and/or CO2 concentration
(AQ and ACi curves), may be interested to test a wee program we have

Photosyn Assistant will take your response curve data (entered as light
(umol photons/m2/s), assimilation (umol CO2/m2/s) and/or internal CO2
concentration (Pa)) and calculate parameters such as apparent quantum
efficiency, convexity, Amax, Vcmax, Jmax, apparent carboxylation
efficiency, CO2 and light compensation points, and respiration rates.
These calculations are based on accepted mathematical models of
photosynthesis. The program operates in the Windows environment (95, NT
or 3.1). It has a role in both teaching and research, and should be of
particular interest to those who use response curves to assay effects of
experimental treatments on leaf photosynthesis.

The program is provided with help for each application, and data output
is possible by printing or copying the results. We welcome suggestions
from users about improving the operation or range of the calculations
and the form of output. You may read more about the program at:

which is also the site for download. The program is provided as a self
extracting zipped exe file, instructions for installation
(straightforward) are provided in a file called readme.txt. At present
the program is available free of charge.

r.parsons at

Richard Parsons
Biological Sciences
University of Dundee

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