Net carbon dioxide exchange rate of wild blueberries is influenced by carbon dioxide concentration, light intensity and air temperature

摘要

The main and interactive effects of carbon dioxide concentration (100 to 1,000 ppm C02J, light intensity (0 to 2,000 umol m2 s1 PPF) and air temperature (12 to 35°C) were examined on upright stems in field studies conducted in 2013. Light intensity was the most important factor accounting for 52% of the net carbon dioxide exchange rate (NCER) model variation followed by carbon dioxide concentration (31%) and temperature (2.1%). Net photosynthesis required light intensities greater than 600 umol nr2s1 for saturation to occur, greatly increased under C02 enrichment and was optimum under C02 concentrations at 24°C. In a related field study examining seasonal changes in whole plant NCER, inclusion of the root and rhizomes were observed to greatly reduce NCER. Quantifying the response of the wild blueberry to these environmental variables and understanding the whole plant NCER dynamics is critical with respect to optimizing plant growth and development and also provides insight into the potential effects of climate change.