Monitoring of Lichen Photosynthesis

by a Fiber Optics Monitoring Head

Originally, the MONITORING-PAM has been developed for multi-site surveillance of higher plant photosynthesis. Nowadays, the fluorescence measuring system is also used for monitoring of fruits during storage and of photosynthesis in submerged plants (see Publications MONITORING-PAM).

Currently, a new surface-inspecting MONITORING-PAM system is being tested. The system has been developed by Rolf Gademann in cooperation with Dr. Leopoldo G. Sancho from the Complutense University of Madrid, Spain, who is interested in long-term performance under extreme weather conditions of crustose and foliose lichens.


The pictures presented here were taken at an experimental site which is located at an altitude of 2.200 meters in the mountain chain Sierra de Guadarrama close to Madrid. At this site, air temperatures range from - 20ºC during winter to +30 ºC in summer.

During summer, lichen thallus temperature at midday can be as high as 60ºC. Annual precipitation is 1800 mm where summers are very dry and most of precipitation falls as snow during the cold season.

To optimize the MONITORING-PAM system for these lichen studies, a number of new features have been implemented:

  Lightweight measuring heads

  Small cosine-corrected ground sensor for photosynthetically active radiation

  Thermocouple for recording ground temperature

  Flexible metal holder for surface attachment

The long-term measurement is powered by solar panels and, at each saturation pulse, date are transferred using GPRS communication via a dedicated server of Walz to the university office.