Of the 14 ecosystems (also known as ecoregions or mega-habitats) defined worldwide, the continent of Australia is home to eight. The sheer size of Australia allows for a variety of vegetation and wildlife, and many of these groups have evolved in relative isolation, separated by features such as high mountain ranges.
Desert and Xeric Shrublands
The majority of Australia's central region is desert. One of the defining features of a desert is not necessarily that it does not rain, but that the rate of evaporation exceeds the rate of rainfall, creating a dry environment. Extreme temperatures are typical, as the lack of humidity and cloud cover creates often excruciatingly hot days and cold nights. Contrary to common belief, however, desert and xeric shrubland regions are home to a diverse array of habitats and wildlife.
Tropical and Subtropical Regions
A small area of Austrailia is home to tropical and subtropical broadleaf forests, thought to be remnants of the ecosystem that dominated Australia's landscape millions of years ago. Contrasting to desert regions, these have a more stable annual temperature and are dominated by evergreen deciduous trees. A much larger region, mostly in the north half of the island, is defined as the tropical and subtropical grasslands, savannas, and shrublands. These areas don't receive enough annual rainfall to allow for tree cover, instead developing into one of the three subcategories, depending on area factors.
Mediterranean Forests, Woodlands, and Shrubs
In the south, a globally rare climate is featured, characterized by hot, dry summers and cool, moist winters. Though rare, this ecosystem features an extraordinary diversity in plant and animal life, housing over 10 percent of the world's plant species.
Along the southeast coast, temperate ecoregions dominate. Like the tropical regions, there are several subcategories, including broadleaf and mixed forests (with an extremely wide range of variation in precipitation and temperature), grasslands, savannas, and shrublands. However, temperate lands are very different from tropical, as they enjoy a much wider range of annual temperatures and unique wildlife.
The Extremes: Montane Lands and Tundra
Montane ecosystems are only a small percentage of Australia, occurring only at high elevations in the southeast. Similarly, the tundra region is only on some of the more polar islands at high latitudes.
- baby elephant image by FotoWorx from Fotolia.com