Abstract
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 ° 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 CO 2 uptake, which we pro- pose 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 ° C. Negative rates of R Laisk imply that this method may become less reliable at low temperatures.
Original language | English |
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Pages (from-to) | 132-143 |
Number of pages | 12 |
Journal | New Phytologist |
Volume | 222 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2019 |
Keywords
- Eucalyptus tereticornis
- acclimatization
- carbon cycle (biogeochemistry)
- climatic changes
- global warming
- respiration
- temperature