caa a22 4500 469096136 CHVBK 20180323133031.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00317836 doi (NATIONALLICENCE)springer-10.1007/BF00317836 Monitoring photosynthetic activity of crustose lichens using a PAM-2000 fluorescence system [Elektronische Daten] [B. Schroeter, T. Green, R. Seppelt, L. Kappen] Summary: CO2 exchange and fluorescence yield of the crustose lichen Buellia frigida were measured in situ by means of a CO2 porometer and a PAM-2000, a newly developed portable fluorescence system. The pulse amplitude modulation system of the PAM-2000 allows measurements in the field under ambient light, temperature and moisture conditions without dark adaptation of the sample. CO2 exchange and fluorescence measurements were well correlated when measured under natural conditions in continental Antarctica during a drying cycle of melt-water-soaked lichen thalli. It was shown that the fluorescence parameter ΔF/Fm′ is a measure of the photosynthetic activity of the lichen. It proved possible, using the PAM-2000, to differentiate the physiological performance of the thallus centre and the marginal lobes. The distribution of water in the thallus during a drying cycle was shown to be inhomogeneous. The photosynthetic rates of B. frigida calculated on an area basis are comparatively high and indicate that this lichen is well adapted to its habitat conditions in this part of continental Antarctica. Springer-Verlag, 1992 Antarctica nationallicence Buellia frigida nationallicence Fluorescence yield nationallicence Net photosynthesis nationallicence Water content nationallicence F m′ : maximum yield of fluorescence under ambient light nationallicence F s : yield of fluorescence at steady state nationallicence Δ F : difference in yield of fluorescence at maximal Fm′ and steady state Fs under ambient light nationallicence NP : net photosynthesis nationallicence PAR : photosynthetically active radiation nationallicence PS II : photosystem II nationallicence Schroeter B. Botanisches Institut und Institut für Polarökologie, Universität Kiel, Olshausenstrasse 40, W-2300, Kiel, Germany aut Green T. Biological Sciences, University of Waikato, Hamilton, New Zealand aut Seppelt R. Australian Antarctic Division, Kingston, Tasmania, Australia aut Kappen L. Botanisches Institut und Institut für Polarökologie, Universität Kiel, Olshausenstrasse 40, W-2300, Kiel, Germany aut Oecologia Springer-Verlag 92/4(1992-12-01), 457-462 0029-8549 92:4<457 1992 92 442 https://doi.org/10.1007/BF00317836 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317836 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schroeter B. Botanisches Institut und Institut für Polarökologie, Universität Kiel, Olshausenstrasse 40, W-2300, Kiel, Germany aut NATIONALLICENCE 700 1- Green T. Biological Sciences, University of Waikato, Hamilton, New Zealand aut NATIONALLICENCE 700 1- Seppelt R. Australian Antarctic Division, Kingston, Tasmania, Australia aut NATIONALLICENCE 700 1- Kappen L. Botanisches Institut und Institut für Polarökologie, Universität Kiel, Olshausenstrasse 40, W-2300, Kiel, Germany aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 92/4(1992-12-01), 457-462 0029-8549 92:4<457 1992 92 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer