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The Kok and Laisk techniques can both be used to estimate light respiration R-light. We investigated whether responses of R-light to short- and long-term changes in leaf temperature depend on the technique used to estimate R-light. We grew Eucalyptus tereticornis in whole-tree chambers under ambient temperature (AT) or AT + 3 degrees C (elevated temperature, ET). We assessed dark respiration R-dark and light respiration with the Kok (R-Kok) and Laisk (R-Laisk) methods at four temperatures to determine the degree of light suppression of respiration using both methods in AT and ET trees. The ET treatment had little impact on R-dark, R-Kok or R-Laisk. Although the thermal sensitivities of R-Kok or R-Laisk were similar, R-Kok was higher than R-Laisk. We found negative values of R-Laisk at the lowest measurement temperatures, indicating positive net CO2 uptake, which we propose may be related to phosphoenolpyruvate carboxylase activity. Light suppression of R-dark decreased with increasing leaf temperature, but the degree of suppression depended on the method used. The Kok and Laisk methods do not generate the same estimates of R-light or light suppression of R-dark between 20 and 35 degrees C. Negative rates of R-Laisk imply that this method may become less reliable at low temperatures.