It rains in summer in the northern part of Australia, Itrains in winter in the southern part of Australia Tall trees are b/w10-30m shrubs are greater than 2m andgrass are b/w 0-15m , Closed forests are greater than 70% intercepted by light ,Openforests are 30-70% 10-30% are woodland
How did climate in Australia change?
The creation of the circumpolar current reduced the temperature and increased aridity. This caused all the rainforest vegetation to disappear and the caused the abundance to heat tolerant plants. Land surface has little mountains and volcanic activity . the weathering caused the leaching
of soils causing phosphorus deficient soil. Evaporation of lakes left saline
Describe the history of fire in Australia
The fire was infrequent but it steadily increased. This is indicated by charcoal …Patterns in sediments.
Fire was less frequent in glacial period. Increased aridity increased fire, Causing the evolution of fire resistant plants
Pleistocene ice ages?
Glacial period : cool unlike elsewhere glaciers
did not grow except in alpine regions, caused sea levels to go down
Interglacial period : warm vice ver
Caused increase in aridity and deserts to expand
What happened in the last glacial: rain forests
were replaced by fire tolerant vegetation and mega fauna were extinct
Evidence of human arrival: -charcoal burning tools , bones
Describe species distribution in Australia.
Species richness is concentrated in the east coast area of the rainforest. Species endemic to aus occur in south west of WA.The reason
endemism occurs in populations are isolated due to : the nulloboar plain , high ph soils act as a barrier. The arid zone separates moisture loving plants from xerophytes