The study of photosynthetic characteristics of two moss species under different light conditions

To explore the adaptive mechanisms of bryophyte plants in Baotianman Nature Reserve, our research determined the photosynthetic characteristics of Thuidium cymbifolium and Mnium immarginatum and revealed a trend of variation with light gradients. Our results showed that M. immarginatum had lower apparent quantum efficiency (AQY), light saturation point (LSP), and light compensation point (LCP) values than T. cymbifolium, indicating that M. immarginatum has a greater ability to adapt to low-light conditions; however, the maximum net photosynthetic rate (Amax) value for T. cymbifolium suggested that it may employ a unique light adaptation strategy. When considering the photosynthetic characteristics of these two species, T. cymbifolium exhibited higher values of water use efficiency (WUE) and stomatal conductance (Gs), which were quite different from intercellular CO2 concentration (Ci) and transpiration rate (Tr). Overall, the results confirmed the hypothesis that a difference in Gs between these two species resulted in adaptation to the environment and represents a survival strategy.