Vegetated escarpments looking back towards the Freycinet Peninsula and Schouten Passage. Photo by Nick Page.
Present Vegetation of Schouten Island Felicity Hargraves
INTRODUCTION
The detail and accuracy of the previous mapping of Schouten Island was greatly improved and 13 new vegetation communities were recorded during this survey. This included two new threatened communities of Callitris rhomboidea forest (NCR), and Seabird rookery complex (SRC). The resulting new Schouten Island vegetation map reflects the great vegetation diversity of the island. It is characterised by diverse heathy, sedgy understoreys and ubiquitous shrubby Callitris rhomboidea pines. The heathy understorey varies from pure Lasiopetalum bicolor, to pure Gahnia filum to diverse coastal heath. The canopy ranges from buttongrass to tall Eucalyptus globulus forest. Despite the island being used for grazing up to the late 1970’s only small areas of exotic weeds can be found, particularly behind the original homestead.
In December 2011 as part of the Hamish Saunders Memorial Expedition, flora species and vegetation communities on Schouten Island was assessed. The vegetation on Schouten Island had been previously mapped by Harris and Kirkpatrick (1982), in which 37 communities ‘defined by structure and dominance’ were identified and mapped. The work by Harris and Kirkpatrick (1982) also postulated reasons for the spatial distribution of the vegetation communities, suggesting that it was most closely related to surface geology and exposure to salt-laden winds as well as fire incidence and intensity, topography, and disturbances by man and other animals. In addition to the vegetation communities, the expedition provided an opportunity to update existing species list of the island’s flora. The island has a diverse flora, having a total of 339 native taxa recorded as present in 1982, which was 75 percent of the 450 species previously recorded from the whole of the Freycinet National Park (Harris and Kirkpatrick 1982). The Freycinet Peninsula exhibited a richer nanophanerophyte and orchid flora, whilst grasses and forbs set Schouten Island apart from the mainland peninsula, although both locations possessed similar floral diversity. Schouten Island also exhibited slightly higher endemism than the peninsula, which Harris and Kirkpatrick (1982) attributed to the large area of dolerite on the island. The work included in this chapter revisits and compliments that of Harris and Kirkpatrick (1982), and describes changes to Schouten Islands flora that have occurred over the last 30 years. Moreover, mapping of the 16 existing and of 13 previously unmapped TASVEG vegetation communities (Harris and Kitchener 2005) of Schouten Island was revised.
Schouten Island • Scientific Expedition • 2011
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