Conditions in many parts of Australia have always been harsh. Our flora and fauna have lived through droughts, fire and flood and they have done this largely by surviving in refuge pockets where conditions are less severe than in other places. But, with European settlement many refuges were destroyed and, in those that remained, feral animals also moved in and killed, or competed with, native species. This is because each species performs a different function within an ecosystem. For example, some species allow pollination to occur, some recycle nutrients, some maintain soil fertility.
Species interact with each other and rely on each other.
One species may be a source of food for another, or may help keep another's population in check. This increased rate of extinction has already led to unstable ecosystems as well as to the loss of potentially useful species. The potential of many plants to supply food, medicines or other commodities remains unexplored. If we are aware of the problem and are concerned for our unique plants and animals, there is a good chance that we will, at least, slow the rate at which organisms are becoming extinct. In 1994 when the ancient Wollemi pine was discovered, only 40 trees existed in its natural habitat.