Drought and Fire: Some survival mechanisms of Australian plants. Almost everywhere in Australia we are either recovering from a drought, in a drought or about to move into a drought. Australia is the world’s driest continent and the native flora has developed various strategies to survive and thrive in the severe conditions. The majority of Australia’s Acacias have developed phyllodes to reduce water loss. Some Proteaceae have leathery leaves that resist wilting. Grevilleas often have a dense layer of hairs on the under surface of their leaves. The hairs form an insulating blanket, which reduces water loss. Many native plants have long taproots, which access water in the sub-soil. Some plants, to reduce water loss, have developed small leaves. Members of the Epacridaceae family are examples of this strategy. Speaking horticulturally, the low water requirement of native plants is good news for gardeners. Water is our most precious resource. Saving water makes good sense both environmentally and economically. In general, native plants have more tolerance to drought than their exotic cousins, particularly those from countries with reliable rainfall.
Fire is another constant in the Australian environment. Native plants have adopted a number of strategies that allows species survival after fairly regular barbequing. Wattles seeds have hard coats that resist the heat of bush fires. Banksias and hakeas have wooden fruits that protect their seeds during fires. Eucalypts have protected buds, which sprout after fire has defoliated the tree. Many Eucalypts and other natives have a swollen root mass known as a lignotuber. Branches sprout from lignotubers after fire.