Preservation Island, Furneaux Group: Two hundred years of vegetation change

Abstract

Preservation Island was the first area south ofSydney to experience the impact ofEuropean settlement. A recent survey of the vegetation resulted in the inventory of140 plant species, 49 ofthese being introduced to the island. Ten vegetation types were mapped, some ofthese being disturbance disclimax communities. The island has a flora typical ofmanyofthe Furneaux Outer Islands. Since 1797, Allocasuarina verticillata, once the likely dominant tree on the island, has been depleted almost to extinction and grassland with a high proportion of exotic species has expanded to cover more than a third of the island. Exotic species propagules have been associated with human activity on the island but also with birds and by sea drift. The high levels ofnatural and human-related disturbance have encouraged establishment of introduced plants. Some obligate-seeding species on the island have been reduced to either precariously low numbers (Acacia ?genistifolia) or extinction (Callitris rhomboidea) by a high fire frequency. The biological productivity of the island was high at the time of initial human settlement because there was an extremely large muttonbird rookery, penguins, macropods and other animals. Scrub and low closed forest were more extensive. Most of the biological capital was exhausted within 30 or 40 years. The significance ofthe island in post-contact Australian history means that more historical remarks are recorded than would otherwise be expected for such an isolated place.