Ecological Importance
Epiphytic bryophytes are one of the major contributors to suspended soils that develop on branches in rainforests (Edwards and Grubb 1977; Ingram and Nadkarni 1993; Heitz et al. 2002). These sponge-like accumulations can store enormous quantities of water in the canopy (Pócs 1980; Frahm 1990a; Veneklaas et al. 1990), extending periods of physiological activity for poikilohydric organisms in their vicinity and allowing desiccation-sensitive organisms to flourish high above the ground. Epiphytic bryophytes and their underlying soils are home to fungi (Stone 1996), arthropods (Winchester 1997), annelids (Wolf 1993c), mollusks, and salamanders in rainforest canopies (pers. obs.). Aboveground adventitious roots are found beneath bryophytes on branches of some rainforest trees, and these roots are frequently mycorrhizal (Nadkarni 1981; Ellyson and Sillett 2003). In addition to the importance of their water-storage capacities, branch-dwelling bryophytes on rainforest conifers often form broad platforms suitable for nesting birds, including the endangered marbled murrelet (Hamer and Nelson 1995).