VCE Outdoor and Environmental Studies Practice Questions

Biological isolation. After Australia separated from the remainder of Gondwana and drifted north, its plants and animals evolved in near-total isolation from other landmasses, with sea acting as a barrier to new arrivals. As a result Australia developed extremely high endemism and a fauna dominated by marsupials, with no native placental land predators apart from bats and, much later, rodents; species such as the koala, the platypus and most eucalypts occur naturally nowhere else. Geological stability. Most of the continent has experienced no recent mountain building or glaciation, so the landscape is very old, flat and deeply weathered. Soils have been leached in place for millions of years without renewal from fresh rock, leaving them shallow and characteristically low in phosphorus, and Australian plants evolved specialised adaptations to cope, including the dense cluster roots of many Proteaceae, sclerophyllous hard-leaved foliage that conserves nutrients, and slow growth rates.