A story in sand. At 150 km long by up to 25 km wide, Fraser Island is reported to be the largest sand island of all. Created by wind, waves and ocean current drawing sand from the ocean to the south, sand moves progressively across the narrow axis of the island roughly from south-east to north-west. Since the island is mostly well-vegetated, this takes quite a long time – dunes on the north-west side have been dated at up to 750,000 years old – the oldest of all dunes. In the process, nutrients are accumulated then buried deeply out of reach of plants, so that the island’s vegetation has a story of development and attrition that matches that of the sand. Exposed coastal grassland and scrub in the south-east develops to tall open forest and rainforest on the central dunes that are 100 to 200 m high. Then, as the dunes move further north-west and degrade, and nutrients are buried deep, the vegetation becomes that of heathlands and swamps on the most infertile north-western sands.

Fraser Island is off the coast of south-east Queensland, Australia.