Australia: The Land Where Time Began

A biography of the Australian continent 

Cape York Peninsula Fire                                                                                                                                                            

In Earth Alive Mary White describes the extent of fires she witnessed on a trip to the tip of Cape York. These were not natural wild fires, they were burnoffs. Research has shown that widespread burning carried out at one time is very destructive. The reason given for the fires by the people involved is to renew the grass for the cattle to provide cattle feed, and to prevent the destructive fires that are started by lightning. When the present savanna landscapes are compared to those in archival material it can be seen just how degraded they are compared to the original ecosystems, the degradation increasing with each burn. The archival material shows what the ecosystems were like after thousands of years of fire-stick farming, but before the introduction of the regular burs by the landholders. White has concluded that the present-day burns are basically different from the fires set by the fire-stick farmers of the past. Some of the changes that occur when fires are too frequent are listed below.

Regular burning damages the trunks of older trees, and after each fire the damage gets deeper, until a point is reached where termites gain access to the heartwood and eat it out. The structure of the tree is weakened and on a subsequent fire the fire can get into the centre of the tree, burning it completely, often after it falls.

Many young trees with thin bark are so badly damaged by a fire that within weeks termites have invaded them, further weakening them, that makes them more susceptible to fires of following burning seasons.

Trees sprout from underground root structures and, together with the sprouting of understorey species, forms a whipstick-type, shrubby regeneration in grassy understorey. The first to flourish are cycads and grass trees, though their numbers are reduced when the fires are too frequent. The numbers of termite nests increases, with apparent increases in termite activity in the soil. Some saplings are killed by each fire, the most fire sensitive species being gradually eliminated, reducing the diversity of the ecosystem. Many of the pasture grasses and forbs that the landholders set their fires to increase are in this category, so are reduced by each fire.

With the ground cover removed before the first rains of the wet season the ground is left exposed to the torrential downpours characteristic of the monsoonal rain in the wet season. The result is erosion that carries away much of the topsoil, that creates further problems by degrading river systems.

The yearly burning of the savannas in Australia and elsewhere is not helping with the fight against global climate change.

According to Mary White, the tropical grassy savannas are being destroyed by the very management practices that are designed to preserve and improve them for beef cattle production.

Sources & Further reading

  1. Mary E. White, Earth Alive, From Microbes to a Living Planet, Rosenberg Publishing Pty. Ltd., 2003
  2. Listen...Our Land is Crying

 

Author: M. H. Monroe
Email:  admin@austhrutime.com
Last Updated 21/10/2016
 
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                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading