Characteristics and dynamics of the sand dune vegetation at North Bay, Tasmania

The vegetation of the coastal sand dunes at North Bay on the Forestier Peninsula was surveyed in 80 quadrats along seven transects. A total of six plant communities was identified; four from the back dunes and two from the fore dunes. The back dunes were dominated by Banksia marginata Cav. and the fore dunes by Spinifex sericeus R.Br. and Acacia sophorae (Labill.) R.Br. Size class analysis of age classes of the back dune vegetation indicated and eventual senescence of the dominant B. marginata and a replacement by closed canopy trees from wet euclypt forest, such as Notelaea ligustrina Vent. Two communities were found to be of high conservation significance: a S. sericeus grassland from the fore dune and a closed-forest community from the back dunes. Both communities are in a relatively undisturbed state, although the S. sericeus grassland has been invaded by exotic herbs. For these significant communities to remain intact, weeds and human activity must be controlled on the fore dunes and fire excluded from the back dunes.