To test these hypotheses, the researchers conducted an experiment in which they cultivated plants in open fields, in a normal-temperature environment, and in a temperature-controlled area using a temperature free-air controlled enhancement system known as T-FACE.
The system comes equipped to control heat emission from the crown of the plants through infrared heaters that enable the temperature of the growing environment to remain at a steady 2C over ambient temperature.
After cultivating the plants with these temperature differences for 30 days, the researchers measured photosynthetic energy dissipation and conducted aboveground biochemical and biomass analyses.
The results of the measurements and analyses indicated that a temperature increase of approximately 2C was able to improve the plants' photosynthetic activity and level of antioxidant protection.
In addition, there was a 32% increase in the leaf area index and a 16% increase in aboveground biomass production compared with plants grown at normal temperature, according to Martinez.
"The increase in temperature during the period of the experiment was favorable for the development of the biochemical and biophysical processes involved in plant growth," he stated.
According to Martinez, some possible explanations for the increase in photosynthetic activity, in addition to the leaf area index and biomass production from samples of Stylosanthes capitata that experienced temperature increases, were the plant's thermal and photosynthetic acclimatization.
The plant adjusted its physiology to not only handle the potentially stressful increase in temperature during its growth phase but also conduct photosynthesis more efficiently and even increase growth under the new climate conditions.
"The results of the study indicated that a temperature increase of up to 2C could be advantageous for growth of so
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Fundao de Amparo Pesquisa do Estado de So Paulo