Scit 140 Notes

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- Most Australian woodlands will survive burning.

- Fire has and continues to be part of the Australian landscape/ecology. Evidence found as charcoal in ancient sediments which also contain pollen grains. For example, in Cenozoic era (65-40 MYA) Australia was humid temperate, covered in rainforest. During the Oligocene Australia became drier and cooler and more arid - thus greater risk of bush fires. 2 MYA Australia began the climate change to wet winters and hot dry summers.

- Dominance of Eucalyptus and Acacia trees and shrubs which cover over 70% of Australia, with gymnosperm (cone bearing plants) less common.

- Dominance of sclerophylls (Sclero: hard and Phyllus meaning leaves) - rigid, small leaves, short internodes and often small in size. Other features include - thick cuticle on the leaf epidermis, sunken stomata in grooves and pits, or protected by hairs,; fibres and thick walled epidermal cell between the epidermis and photosynthetic mesoplyll. These plants are adapted to soils of low fertility even where rainfall is high.

- Fire adaptations - Xanthorrhoea’s flowers/seed are stimulted by fire; epicormal buds sprout; plant might burn but the seeds/fruits and capsules survive hakeas, banksias and teatrees. Acacia seeds need to be burnt before they germinate.

Fire has and continues to be part of the Australian landscape/ecology. Evidence found as charcoal in ancient sediments which also contain pollen grains. For example, in Cenozoic era (65-40 MYA) Australia was humid temperate, covered in rainforest. During the Oligocene Australia became drier and cooler and more arid - thus greater risk of bush fires. 2 MYA Australia began the climate change to wet winters and hot dry summers.

Dominance of Eucalyptus and Acacia trees and shrubs which cover over 70% of Australia, with gymnosperm (cone bearing plants) less common.

Dominance of sclerophylls (Sclero: hard and Phyllus meaning leaves) - rigid, small leaves, short internodes and often small in size. Other features include - thick cuticle on the leaf epidermis, sunken stomata in grooves and pits, or protected by hairs,; fibres and thick walled epidermal cell between the epidermis and photosynthetic mesoplyll. These plants are adapted to soils of low fertility even where rainfall is high.

Fire adaptations - Xanthorrhoea’s flowers/seed are stimulted by fire; epicormal buds sprout; plant might burn but the seeds/fruits and capsules survive hakeas, banksias and teatrees. Acacia seeds need to be burnt before they germinate.

Food chains/ food webs:

- Food chain: The arrows don't indicate what eats what. The arrow tells us how the energy is transferred. E.g. Grass is an energy source for the consumers. Primary consumers (the first eaters). Top of the food chain comes from the secondary consumer. When all the consumers die it will decompose.

- Food webs: EXAMINABLE !!! Know the arrows. The arrow Is a food/energy source. Plants are producers. The arrows can tell you about their diet, multiple food sources.

Food web (Antartica)

- Identify the producers, the herbivores, the third order consumer

- Make sense of the diagram and write it in text

- If I have a diagram can I make a chain !

Learning about lifecycles, adaptation, and ecology.

Slide 25 ! Importance of decomposers. Break down death plants/ animals, eat their wastes, and return nutrients to the soil. E.g. Earthworms, flies, wasps, bacteria, dung beetles, wasps, and cockroaches

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