Fig. 3
Effects of imbibition in water vapour and liquid water, and oxygen, on the thermal fingerprints of L. pulmonaria thallus discs (Experiment 2). Left panels show imbibition under normoxia (air) and right panels show imbibition under anoxia (air was replaced by flushing with N2 gas). "Live" samples (green) were untreated and "dead" samples (red) were killed by microwaving the hydrated thallus discs at 800 W for 30 s. a, b Viability of lichen discs before (t0; closed symbols) and after (t170min; open symbols) the experiment, assessed by the maximal photochemical efficiency of photosystem II. Data show means ± SE (n = 15 lichen discs). Green and red lower-case letters above the bars denote significant differences between treatments ("live", "dead") and between start (t0) and end (t170min) of the experiment (P < 0.05; Kruskal–Wallis test). c, d Moisture content (MC) of L. pulmonaria thallus discs during rehydration. Data show means ± SE of a second set of thallus discs (n = 5). The asterisk indicates that "life" and "dead" thallus discs differed significantly (P < 0.05; Mann–Whitney U test). e, f Thermal fingerprints of "live" and "dead" thallus discs showing median values of relative temperature (rT) during imbibition. Data are medians of n = 15 "live" and n = 15 "dead" thallus discs. g, h Differences between the fingerprints of "live" and "dead" thallus discs (ΔTlive–dead). Horizontal green bars indicate the time windows in which the T values of "live" thallus discs differed significantly from that of "dead" ones (P < 0.05; Two Sample t-test). Open blue horizontal bars indicate the time periods of hydration by water vapour and closed blue bars indicate imbibition in liquid water from below