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Our primary measured response variables were ACi curves (using a program in Licor 6400 gas exchange systems) setting the mixer CO2 to 400, 300, 200, 150, 125, 100, 75, 50, 25, 400, 400, 600, 900, 1250, 1500, 1750, 2000 ppm every 3 minutes and the light saturated at 1800 mol photons m-2 s-1. Dark respiration (Rdark) was measured after turning off the light source for 10 minutes.

In most cases, measurements were made in field on detached branches with the xylem immediately re-cut under water. Leaves were stored with wet tissue and transported to the laboratory in the afternoon where leaf fresh mass and area were determined – thereafter, leaves were oven dried/weighed and then shipped to Canberra for chemical analysis.

Measurements were made on species for which were sufficient replicates and for which removal of short branches containing several fully expanded leaves would not have an adverse effect on the growth/health of individual trees. Measurements were measured on 1 to 4 trees from each study species.

These measurements provided data on Asat (light saturated photosynthesis), Amax (light saturated photosynthesis and at saturating atmospheric CO2 concentration), stomatal conductance (Gs), Internal CO2 concentration (Ci), Rdark. Maximum velocity of the carboxylase (Vcmax), maximum rate of carboxylation allowed by the electron transport (Jmax) and CO2 evolution from mitochondria in the light, other than that associated with the PCO cycle (Rlight) were calculated from Farquhar model and also Bernacchi correction for temperature.