The effects of temperature and moisture on CO 2 uptake and total resistance to water loss in the antarctic foliose lichen Umbilicaria antarctica

• Published in: New Phytologist
• Main Authors: HARRISSON, P. M., WALTON, D. W. H., ROTHERY, P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1989
• Subjects: Plant Science; Physiology; Antarctic; The Antarctic; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1469-8137.1989.tb02362.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-8137.1989.tb02362.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1989.tb02362.x; https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1989.tb02362.x

summary Maximum net photosynthesis of field‐fresh thalli, illuminated at 200 μmol photons m −2 s −1 (PAR), was attained at 13 °C and 1.10 g g −1 water content. Small but significant rates of photosynthesis were measured at −5.5 °C. Depression of net photosynthesis at high thallus water contents is explained in terms of thallus anatomy. Calculation of evaporative resistance of the thallus by a new method showed a moisture‐dependent response pattern, and was in agreement with direct observations made on other foliose species.