Potential for fast chlorophyll a fluorescence measurement in bryophyte ecophysiology

The aim of the study was to analyse if the measurement of fast fluorescence induction kinetics in bryophyte samples in field conditions could be used for characterizing the photochemistry of photosynthesis in bryophytes. Bryophyte samples were collected in five different habitats of the boreo-nemoral zone growing on various substrates. Twenty-four species were epigeic, six epilithic, ten epiphytic, three epixylic, and six semi-aquatic or aquatic. Extremely high variation was found for fluorescence parameters between bryophyte samples. Performance Index showed the highest variability, reaching 160% in the case of epiphytic bryophytes. There were statistically significant differences for mean values of Fv/Fm, RC/ABS, and Fv/F0 between epigeic and epiphytic bryophyte samples as well as between epiphytic and semi-aquatic & aquatic samples. For Performance Index, a significant difference was observed only between epiphytic and epigeic bryophytes. It was concluded that bryophytes display a low intensity of the photochemistry of photosynthesis even in relatively wet habitats. In general, measurement of fast fluorescence induction kinetics in field conditions could be a rapid and efficient tool to obtain quantitative data useful for ecophysiological studies.