EPIPHYTES ON AN OLD HUON PINE TREE (LAGAROSTROBOS-FRANKLINII) IN TASMANIAN RAIN-FOREST

The epiphytic flora of an old Huon pine (Lagarostrobos franklinii) in western Tasmania comprises 76 lichens, 55 bryophytes, and 16 vascular plant species. There is a vertical zonation of the cryptogams on the t ree, with little overlap between basal and canopy floras. Bryophytes a re the dominant life form at the base of the tree but there is a marke d increase in the diversity of lichens, and in the ratio of lichens to bryophytes, with increasing height. The longevity of the tree is mani fest in the development of a wide range of microhabitats but it seems unlikely that any of the cryptogams require such longevity per se to b ecome established as rainforest epiphytes. However, several of the vas cular species on the tree are normally terrestrial and their occurrenc e as epiphytes is dependent on the development of sufficient peat to s upport their root systems. Such a process is likely to be very slow, r equiring a long-lived host species. The study illustrates the richness of lichens and bryophytes in the forest ecosystem and the extent to w hich even a single tree can contribute to the biodiversity of a forest site.