The Browning of Australia

This book traces the evolution of the driest vegetated continent from the green and forested, well-watered piece of Gondwana. Like the birth, maturing and aging of an oragnism, the evolutionary stages "Rifting", "Drifting" and "Drying" have produced the modern land we know today - a wide brown land, time-worn and unique.

How Australia broke free from Gondwana, and the geological processes which were involved, forms the "Rifting" section of this book. "Drifting" documents the changing vegetation, climate and landscapes as the Island Continent moved northwards away from Antarctica. The "Drying" of the Australian continent that resulted in its blown-sand and stony deserts, its vast arid and semi-arid zones and its present-day vegetation patterns began with the formation of the North Polar ice cap about 2.4 million years ago.

The arrival of Aboriginal people in the continent possibly as long ago as 140,000 years, and the impact of their "fire-stick farming" on an ice age-affected land was profound, altering the nature of vegetation over much of the continent. The impact of European settlement on this unique land in the last 200 years has been devastating. The reasons why are clearly seen in the "Drifting" and "Drying" story. "Unbalancing the Biota" looks at current problems from the prehistoric perspective gained from the study of the development of the driest vegetated continent from a green and forested piece of Gondwana.