Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 What is Australian rainforest?
- 3 The sclerophyll problem
- 4 The edaphic theory I. The control of rainforest by soil phosphorus
- 5 The edaphic theory II. Soil types, drainage, and fertility
- 6 The climate theory I. Water stress
- 7 The climate theory II. Light and temperature
- 8 The fire theory I. Field evidence
- 9 The fire theory II. Fire, nutrient cycling, and topography
- 10 The fire theory III. Fire frequency, succession, and ecological drift
- 11 The fire theory IV. Aboriginal landscape burning
- 12 The fire theory V. Aridity and the evolution of flammable forests
- 13 The fire theory VI. Fire management and rainforest conservation
- 14 Summary
- References
- Index
14 - Summary
Published online by Cambridge University Press: 23 November 2009
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 What is Australian rainforest?
- 3 The sclerophyll problem
- 4 The edaphic theory I. The control of rainforest by soil phosphorus
- 5 The edaphic theory II. Soil types, drainage, and fertility
- 6 The climate theory I. Water stress
- 7 The climate theory II. Light and temperature
- 8 The fire theory I. Field evidence
- 9 The fire theory II. Fire, nutrient cycling, and topography
- 10 The fire theory III. Fire frequency, succession, and ecological drift
- 11 The fire theory IV. Aboriginal landscape burning
- 12 The fire theory V. Aridity and the evolution of flammable forests
- 13 The fire theory VI. Fire management and rainforest conservation
- 14 Summary
- References
- Index
Summary
Rainforests in Australia occur as scattered islands within vast tracts of the quintessential Australian vegetation dominated by Eucalyptus and Acacia. Rainforest ‘islands’ are found from Tasmania in the temperate zone to the monsoon tropics in the north across wide gradients of rainfall, altitude and temperature. In this book, I argue that their patchy distribution is the consequence of tens of millions of years of fires started by lightning and other natural causes. Fire became a feature of the Australian landscape as the continent became progressively drier. This occurred because of the dominance of the subtropical high pressure system beginning in the mid Tertiary when the continent drifted into the mid latitudes, the thermal gradient between the equator and the South Pole intensified, and the Antarctic ice sheet formed. An increase in the frequency of wildfires triggered a major diversification of the fire-tolerant biota. In plants, there was selection for new traits such as serotiny, and the refinement of pre-existing traits such as the lignotuber. Some fire-tolerant vegetation became fire-adapted and ultimately fire-promoting, sealing the fate of most rainforest vegetation. This evolutionary divergence is responsible for the fundamental and often sharp ecological and floristic dichotomy of the current Australian biota into rainforest and non-rainforest types. Thus the evolution of the current Australian flora was forged in a fiery environment in which the ancestral rainforests become scattered and burnt.
- Type
- Chapter
- Information
- Australian RainforestsIslands of Green in a Land of Fire, pp. 285 - 288Publisher: Cambridge University PressPrint publication year: 2000