Far North Queensland, Leaf Level Physiology, Chemistry and Structural Traits Data, Robson Creek Site, 2012 

This record contains data on the leaf level physiology, chemistry and structural traits from the Robson Creek Site, Far North Queensland measured in 2012. There are two data sets provided: 1) response variables containing parameters associated with photosynthetic light response curves (Al) and 2) response variables containing parameters associated with photosynthesis and intercellular carbon dioxide curves (ACi). 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
JCU/TERN (funded travel, accommodation and equipment hire); ARC DP09 grant (DP0986823) Out of the darkness: predicting rates of respiration of illuminated leaves along nutrient gradients 

Data not provided. 

1) Light response curves (AI): The primary measured response variables were AI curves (using a program in LI-COR 6400 gas exchange systems). A series of light levels were used in the light response curves starting from 1800 µmol photon m^-2 s^-1 and gradually decreased to 0 via 1500, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, µmol photon m^-2 s^-1 at 400ppm CO₂. Each light level was applied for minimum of 60 seconds and maximum of 120 seconds using an auto-program. Dark respiration (R_dark) was measured after turning off the light source for 10 minutes.

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 made on 1 to 4 trees from each study species. These measurements provided data on A1800 (light saturated photosynthesis), stomatal conductance (g_s), Internal CO₂ concentration (C_i), and R_dark. CO₂ evolution from mitochondria in the light, other than that associated with the PCO cycle (R_light) was calculated from the Kok method.

2) ACi Curves: Our primary measured response variables were AC_i 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 µmol photons m^-2 s^-1. Dark respiration (R_dark) 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. In addition to the above work on detached branches, we used an additional 3 days of aerial platform access to allow in-situ measurements of different day temperatures for 9:30AM, 10:30AM, 11:30AM, 12:30PM, 13:30PM, 14:30PM, 15:30PM. 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 made on 1 to 4 trees from each study species. These measurements provided data on A_sat (light saturated photosynthesis), A_max (light saturated photosynthesis and at saturating atmospheric CO₂ concentration), stomatal conductance (g_s), Internal CO₂ concentration (C_i), and R_dark. Maximum velocity of the carboxylase (V_cmax), maximum rate of carboxylation allowed by the electron transport (J_max) and CO₂ evolution from mitochondria in the light, other than that associated with the PCO cycle (R_light) were calculated from Farquhar model and also Bernacchi correction for temperature.