VCE Biology Unit 2Area of Study 01

Adaptations of OrganismsChapter 13.4

Surviving a major disturbance

Chapter 13.4 Surviving a major disturbance

Fire• Victoria – major fires in 1851, 1898, 1905, 1906, 1912, 1914,

1919, 1926, 1932, 1939, 1942, 1943, 1944, 1952, 1962, 1965, 1968, 1969, 1972, 1977, 1980, 1983, 1985, 1997, 1998, 2002, 2003, 2005-2006, 2006-2007 and 2009Department of Sustainability and Environment “Fire and Other Emergencies”http://www.dse.vic.gov.au/dse/nrenfoe.nsf/childdocs/-D79E4FB0C437E1B6CA256DA60008B9EF?open

• Most Australian plants are adapted to fire.

Bushfire, La Trobe Valley, February 2009

Chapter 13.4 Surviving a major disturbance

Epicormic buds of eucalypts• Flammable oils in leaves result in rapid hot fire• Destroys crowns of trees but only chars the trunks• Bark is good insulator against heat• Bark protects underlying cambium layer• Cambium layer produces regenerative growth of

bark and woody tissue

Chapter 13.4 Surviving a major disturbance

Epicormic buds of eucalypts (continued)• Epicormic buds, which lie under the bark of stems

and roots, allow sprouting and re-growth• For plant stem to survive, both cambium layer and

epicormic buds must survive• Epicormic buds are kept dormant by growth

inhibitors produced by the crown of the tree

Lady Talbot Drive, Marysville, August 2008

Lady Talbot Drive, Marysville, February 2009

Lady Talbot Drive. Marysville. April 2010

Lady Talbot Drive, Marysville, April 2010

Chapter 13.4 Surviving a major disturbance

Lignotubers – underground protection• When all above ground parts of tree has been

destroyed, plants that have lignotubers, rhizomes (underground stems) or root suckers can regenerate from subterranean buds

• A lignotuber is a swelling at the base of the stem where dormant buds lie.

Lignotubers

Chapter 13.4 Surviving a major disturbance

Tough wattle seeds• In Australian forests, Acacia species make up

most of the understorey• Acacia seeds have hard outer seed coats and

can survive high temperatures and require heat to germinate.

Acacia seeds

Acacia seedlings after fire

Chapter 13.4 Surviving a major disturbance

How do animals live with fire?• Small animals killed by fire, but fire burns in a mosaic pattern

and unburnt areas are left.• Predator birds patrol in front of fire front to catch prey• Butcherbirds eat animals exposed by lack of undergrowth• Parrots eat seeds and young plants in the regenerating forest• Some animals live underground to escape fire and predators

Tarra Bulga National Park, December 2009

Just north of Tarra Bulga National Park, December 2009

Just north of Tarra Bulga National Park, December 2009