GROWTH-RESPONSES OF 6 BRYOPHYTE SPECIES TO DIFFERENT LIGHT INTENSITIES

The growth responses of Brachythecium rutabulum, Eurhynchium praelongu m, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium pur um, and Thuidium tamariscinum, growing under seven different light con ditions, were determined in a 36-day laboratory experiment. Biomass pr oduction, relative growth rate, chlorophyll content, and morphological plastic responses (bending of die shoots) were determined following i nitial and final harvests. All species achieved greater biomass as irr adiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophy tes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear dif ferences were observed in the ratios of chlorophyll a to b for all the species.