Bryophytes and associated algal communities from an exposed cliff face on O'ahu (Hawai'i, USA)
Ress, Jennifer A.; Lowe, Rex L.
A diverse bryophyte flora inhabits the exposed rock of Nu'uanu Pali, a cliff face on Ko'olau Mountain in southeastern O'ahu (Hawai'i, USA). Bryophytes are known to provide habitat for epiphytic algal communities and may be an important substrate in aerial habitats due to their ability to retain moisture. Moisture is predicted to play an important role in structuring aerial algal communities. We analyzed the algal community composition from nine different bryophyte taxa, eight species of moss and one group of unidentified liverworts, to examine possible algal community fidelity to the bryophyte taxa. Physical and chemical factors, including aspect, moisture levels, light levels, and pH were measured at each sampling location. Algal communities were dominated by cyanobacteria and diatoms. There was no association found between bryophyte taxa and algal community composition. Relationships were identified between moisture availability, aspect, and light with algal community composition. Cyanobacterial taxa drove the clustering patterns seen in these communities. Diatoms were found to be almost completely absent from communities in south facing locations. While there was no relationship between algal community composition and bryophyte identified, this study provides additional insight into understanding aerial algal ecology and the factors that influence community structure.