The Australian Experience
The frequent use of fire in Australia by humans is much more recent than the above examples; that is, approximately 40 to 50 000 yr BP when the continent was first settled.
Over the course of geologic and evolutionary time fire would have altered landscapes and vegetation. Overall there appears to have been an increase in fire activity through the late Cenozoic, associated with drier and more climatically variable conditions, and an increasingly fire tolerant vegetation. Charcoal records support this increase in burning, and a shift to fire tolerant vegetation: there was widespread replacement of Casuarinaceae species by sclerophyllous vegetation, particularly eucalypts. This suggests that fire had an increasingly important role in vegetation dynamics in the Quaternary.
It is worth noting however that the driving force for the evolution of sclerophyllous vegetation is highly contentious, with other factors such as water availability and soils also potentially playing a role.
Hot topic: Did human fire change the Australian landscape?
While there are records indicating change in fire occurrence, just how important the influence of people was in the evolution and dynamics of Australian vegetation is much more uncertain. There remains significant debate on this topic today.
Some authors claim that Aboriginal people and their use of fire would have significantly altered the face of the landscape. Others say that Aboriginal people probably had very little impact on existing fire regimes and pre-European vegetation cover.
Activity: People and the Australian landscape
Did the arrival of people transform the Australian landscape?
Tim Flannery is a scientist and author of several popular non-fiction books. In 1994 he published the controversial book ‘Future Eaters’ in which he sets out several hypotheses about the ecological history of Australia, including the role of the arrival of people in transforming the Australian landscape with fire.
Have a look at the main points raised by Tim Flannery’s book relating to fire, and look at the responses to these hypotheses from a range of critics at:
Taming the Fire - Hypotheses and Eating the Future - Hypotheses
These resources are located on the ABC website The Future Eaters.
Further evidence for human transformation of the Australian landscape with fire is presented by Miller et al. (2005) who studied changes in bird diets. They suggest that firing of the landscape and subsequent changes in vegetation caused Australia’s megafauna extinction.
Despite this new study there still remains much debate as to the role people played in transforming the landscape using fire. An alternative explanation is that humans caused megafauna extinction which in turn caused the vegetation to change; a sudden disappearance of large herbivores could have triggered an expansion of shrublands causing shifts in diets.
Reading:
Miller, G.H., Fogel, M.L., Magee, J.W., Gagan, M.K., Clarke, S.J. & Johnson, B.J. (2005) Ecosystem collapse in Pleistocene Australia and human role in megafaunal extinction. Science 309: 287-290.
Further reading
The following reading continues with the ‘Future Eater’ theme, and reviews what is known about the impact of Aboriginal burning on the Australian landscape.
Read the ‘Summary’ and ‘General Conclusions’, even if you don't have time to read the whole article.
Reading:
Bowman, D.M.J.S. (1998) Tansley Review No.101: The impact of Aboriginal landscape burning on the Australian biota. New Phytologist 140: 385-410.
Palynological records (pollen and spore records) from the Holocene indicate that there was generally relatively constant fire activity during this period, with greatest variation being during the period of European occupation. These data indicate that burning increased during the early part of European settlement to levels higher than at any other time during the Holocene in all major vegetation types, but was then followed by a period of reduced burning to levels lower than at any other time during the Holocene.
