Geography of Australia
Australia is a nation comprised by the Australian mainland, the island of Tasmania, and the multiple other smaller islands under its jurisdiction. The Australian mainland is a large area of 2,941,300 square miles. It has over 21,000 miles of coast and is often considered the largest island on earth. Due to its size and geographic location, Australia consists of 40 ecological regions within 8 different terrestrial biomes. This varying ecology lends itself to a rich biodiversity within the country. This article takes a look at those different regions.
Tropical and Subtropical Moist Broadleaf Forests
Located in Northeastern Australia, this biome contains 3 different ecoregions in Australia, including the Lord Howe Island Subtropical Forests, the Norfolk Island Subtropical Forests, and the Queensland Tropical Rainforests. These forests are located along the equatorial belt and experience heavy rainfall and consistently warm temperatures. The latter ecoregion contains evidence of the ancient Gondwanan Forests which has also provided researchers with the most thorough evidence of plant and animal evolutionary processes throughout the last 415 million years. Although these forests cover a very small percentage of the Australian landmass, they are home to 65% of Australia’s fern species, 36% of mammal species, and 50% of bird species. The region has suffered deforestation and is currently threatened by invasive species.
Temperate Broadleaf and Mixed Forests
These forests have a varying range of temperatures and rainfall, as well as a mix of deciduous and evergreen trees. This biome is home to 5 ecoregions in the country, including the Eastern Australian Temperate Forests, the Southeast Australia Temperate Forests, the Tasmanian Temperate Forests, the Tasmanian Temperate Rainforests, and the Tasmanian Central Highland Forests. These areas have been heavily hit by the timber industry as well as deforestation to make room for crops and livestock grazing. The agricultural industry prizes this area for its rich soils which are home to roughly 693 Eucalyptus tree species. The areas are abundant with endemic bird species as well.
Tropical and Subtropical Grasslands, Savannas, and Shrublands
Grasslands and shrublands exist throughout the country due to an extreme lack of rainfall that prohibits tree growth in many areas. Although rainfall is not consistently heavy, these ecoregions do experience some monsoons that create wetlands. This particular biome is home to 8 ecoregions. Endemic to these areas are over 50 vascular plant species and numerous fish and frog species. Habitat destruction here has not been as pronounced as in the forest lands although there has been some reported declines in native mammal species which may be due to the rampant populations of feral cats.Also destructive are current fire-burning practice which happen more frequently than they might naturally occur. This has prohibited the growth of some larger plants.
Temperate Grasslands, Savannas, and Shrublands
While also flat and lacking many large trees, this biome differs from its tropical counterpart in that it experiences generally cooler, and more varied, temperatures year-round. Housing two different ecological regions, a large portion of the area has been damaged by sheep herding and wheat farming activities. Many threatened species make their home here including the superb parrot, Mackays burrowing skink, and the red goshawk. Since native plants have been removed to make way for sheep and wheat, many plants and animals are now endangered.
Montane Grasslands and Shrublands
This biome holds only the Australian Alps Montane Grassland ecoregion, which is located at just over 1,300 meters above sea level. Due to the altitude, this is a colder climate than the previously mentioned regions and therefore hosts different types of plant life. Mountain ash and snow gum are common trees and above the tree line, sphagnum bog begins to take over. Animals living here include Alpine thermocolor grasshoppers, Baw Baw frogs, and Red-necked wallabies. The majority of this region has been protected and has not suffered the amount of destruction as the others.
The Australian tundra is a frozen desert of sorts and is located solely on the Antipodes Subantarctic Islands, which are made up of 5 island groups. This area is marked with grassland and shrubs as well as algae and lichen on the rocks. The Cyathea tree fern is endemic here. These islands have no native mammals, reptiles, or amphibians but do host a breeding ground for seals, sea lions, and elephant seals. All of the islands have been classified as natural reserves and therefore have not been subjected to widespread human destruction.
Mediterranean Forests, Woodlands, Scrubs
These biomes contain 10 different Australian ecoregions. Their similarities include hot, dry summers and cool, moist winters. It is considered a rare habitat because it is only found in 5 places on earth, but it is home to a wide range of biodiversity. The karri, the largest tree in Australia, can be found here as well as mosses, ferns, and liverworts. The western ringtail possum, brush-tailed phascogale, and the southern brown bandicoot all live here. The forests and woodlands are threatened by deforestation to make space for agriculture.
Deserts and Xeric Shrublands
These biomes are home to 10 ecoregions in Australia and have interesting climatic characteristics. While rainfall differs throughout the ecoregions, they all share a rapid evaporation rate. In fact, the moisture evaporates faster than it falls. The daytime is characterized by extremely hot temperatures while at nighttime the climate is cold. Many of the people living in these areas are aboriginal Australians. The area hosts many endemic species and is easily damaged by livestock herding and grazing. The red kangaroo, bilby, emu, and desert tree frog all make their home here.