Zs. P. Komáromy szerk.: Studia Botanica Hungarica 16. 1982 (Budapest, 1982)

Rajczy, Miklós: About the length of active life of some xerophytic cryptogams in the dry season

Discussion Unfortunately, there was no possibility to measure either the respiration or the photosynthesis of the examined plants this time. Anyhow, during that time when the moss leaves were not crisped (i.e. the turgor was nearly normal) the plant lived a normal active life to all probability. That means these plants have 6-7 hours a day to live under such conditions and during the last 1-2 hours there is enough light for photosynthesis! There is no doubt that this very quick water uptake is partly due to the prolongated previous period of high air humidity. Nevertheless, it is sure that a more arid day-time would not have lengthened the water uptake till the critical moisture-content level for over 2 hours. An unsolved problem for me is the weight-decreasing period before dawning. Probably it was an evaporating period (see Fig. 2 - the temperature of the moss-tuft dropped under the air temperature!), but this is not sure. Unfortunately, the precision of the Assman Psychrometer is very low above 90-95% relative humidity that is why the fine changes remained unchecked. W Fig. 3. The process of changing of the water content of the examined plants (W - water content/ dry-weight; Fl, F2 - Cladonia furcata samples: ; Cl, C2 - Cladonia convoluta samples: ; TI, T2 - Tortula ruralis samples: ; other signes see in Fig. 2)