A diverse bryophyte flora inhabits the exposed rocks on Nu'uanu Pali, on Ko'olau Mountain, in southeastern O'ahu (Hawai’i, U.S.A.).  The structures of bryophytes are known to provide habitat for epiphytic algal communities and are important in aerial habitats, such as that of Nu'uanu Pali, due to the ability of bryophytes to retain moisture for use by their algal associates.  We predicted that different bryophyte species would support different algal communities due to the different microhabitats created by these bryophyte species.  

Bryophytes, and associated algal communities, were collected in February and March, 2008.  Physical and chemical factors, including aspect, moisture levels, light levels, and pH were measured at each site.  Patterns were explored via non-metric multidimensional scaling and analysis of similarities on a Bray-Curtis similarity matrix.

The analysis demonstrated an association between bryophyte species and aspect, north versus south, with algal community composition.  This is most likely due to the relationship between sun exposure and moisture loss from the bryophytes and associated algal communities.