australasia

Australasia is made up of the continent of Australia and its neighboring islands. It is part of the larger political and geographic region called Oceania, which stretches from West Papua to Hawaii. Australia, the largest landmass in this area, has been called “the last of lands,” “the oldest continent,” and “the last frontier.”

Although this continent is not actually the oldest in the world, many of its rugged and beautiful landscapes seem untouched by time because of Australia’s isolation. For 50 million years, the animals and plants on Australia have been separate from the rest of the world’s landmasses. Surrounded by vast ocean like an island, wildlife was free to evolve and compete with each other in unique ways. Only Australia has mammals that lay eggs: the funny duck-billed platypus and four species of spiky echidna. Marsupials like the kangaroo and koala are abundant. Unlike other mammals, marsupials evolved to keep their developing young not inside their bodies, but in an external pouch. There are many odd-looking and interesting birds, like the colorful, dinosaur-like cassowary, which reminds many of a velociraptor because of its sharp claws and the skin-covered casque on top of its head.

Australia is famous for its outback, the mostly unpopulated wilderness that contains the largest intact savanna in the world. But Australia is also home to lush coastal forests and coral reefs. When European colonization of Australia began in 1788, so too began massive deforestation of the continent. Logging of native forests continues in Australia, and many of its endemic animals, like the koala, are vulnerable because of unsustainable devolvement. Now conservation groups and ecologists are working hard to protect Australia’s unique wildlife and environment.

Ecosystem of the Australian savanna

The greatest intact savanna in the world is in the north of Australia. This savanna wilderness is vast, covering about a quarter of the continent but home to only an estimated five percent of its people. These lush grasslands are made up of six different savanna regions where some of the most unusual wildlife in the world are found.

Because Australia is separated from other continents by the ocean, its isolated wildlife have evolved in unique ways. Marsupials like red kangaroos and wallabies keep their developing babies close to them in an external pouch. These babies may poke their tiny heads out while their moms graze the savanna. The mysterious compass termites use grass to build gigantic mound structures as tall as a person that all eerily point on an exact north-south axis. One of Australia’s best-known animals is the large flightless emu. Looking more like their dinosaur ancestors than most other birds, they stand six feet tall, hiss loudly at predators, and run across the grasslands at speeds of up to 30 miles an hour. The savannas have been named a “global ecoregion,” because they give scientists an understanding of biodiversity on a global scale.

BIGGEST BENEFITS

Grasslands around the world provide rich grazing and farmland. While an estimated 70 percent of global grasslands are giving way to human development, the Australian tropical savanna remains mostly intact. This grassland provides rich soil for farming and some of the Australia’s largest cattle grazing areas. The savanna also is home to many aboriginal communities who continue their rich cultural traditions and land stewardship today. The people who live on the savanna depend on the land for their livelihood.

Ancient lava flow created the famous Great Basalt Wall and the hollow cave maze of the Undara Lava Tubes.

The Gouldian finch of the Australian savanna is considered one of the most beautiful birds in the world.

Dingoes are wild Australian dogs that prey on rabbits, wallabies, and even kangaroos.

Groups of kangaroos are called “mobs.” Female kangaroos are called “flyers,” males are called “boomers,” and babies are called “joeys.”

Millions of years ago, ancestors of the emu could actually fly. Scientists think that after the dinosaurs became extinct, these birds had no real predators and access to more food. They started to grow in size and after many generations, evolution took its course and the birds became too heavy to fly.

GREATEST THREAT

Overgrazing and invasive animal species harm the grasslands. But global warming is the greatest threat to the Australian savanna. Like all grasslands, these are expected to have cycles of natural wildfires. As global temperatures rise, dry seasons are extended. Longer dry seasons mean more dry grass, which acts as fuel for the wildfires. Large, out-of-control late-season wildfires are threatening grass and scrublands worldwide. Conservationists are working with aboriginal communities in Australia to manage the land to try to prevent late-season fires.

Ecosystem of the Tasmanian Temperate rainforest

Around 180 million years ago, dinosaurs ruled the earth on the supercontinent called Gondwana. Over time, Gondwana broke apart, creating Australia and the other continent and islands in the southern hemisphere. Many trees, mosses, and invertebrates that lived alongside the dinosaurs—called “living fossils”— are still found in Tasmania’s forests today. The Tasmanian temperate rainforests are part of a UNESCO World Heritage Site because of their unique connection to the past.

Tasmania is a small island state of Australia, but despite its size, there are eight different biomes on the island. The quiet and cool rainforest covers 10 percent of Tasmania and is one of the most pristine, unchanged Gondwana wilderness regions in the world. Many of the flowers and trees, like the rare King’s lomatia shrub, have grown in Tasmania for over 60 million years. Here, the Eucalyptus regnans (also known as mountain ash trees) grow up to 
300 feet tall, rivaling the trees of the redwood forest. Soft green moss covers the forest floor, and coral-like blue and red fungus dots the landscape.

The rainforest is also home to ancient invertebrates like velvet worms, which have been around for 300 million years, predating the existence of insects on earth. They hunt in packs like wolves and capture their prey by shooting streams of sticky slime out of their faces! Tasmania is also home to some of the fluffiest and cutest marsupials—like the Tasmanian pademelon (which looks like a miniature kangaroo), the tiny spotted quoll, and of course, the famous Tasmanian devil. There is still much to be discovered in the Tasmanian temperate rainforest, and people are still encountering and naming new species of wildlife today!

BIGGEST BENEFITS

The large and dense trees of the Tasmanian temperate rainforest help to create oxygen and precipitation in the area. It is also home to unique natural resources like the Huon pine tree, which has golden yellow colored lumber, and the leatherwood plant, which beekeepers depend on to produce special leatherwood honey.

Wombats like building their homes near creeks in the rainforest and are famous for their cube-shaped poop.

The thylacine (also known as the Tasmanian tiger) was the largest carnivorous marsupial, dating back 23 million years. Unfortunately, people saw them as a threat to livestock and hunted them to extinction in the 1930s.

The UNESCO World Heritage Site covers 20 percent of Tasmania and is made up of 19 separate national parks or conservation areas.

The famous Tasmanian devil got its name from its high-pitched screeches and growls.

GREATEST THREAT

Most of the Tasmanian temperate rainforest is protected, but an increase in wildfires caused by climate change and over logging of unprotected areas has threatened this ecosystem. Unlike redwood forests, this ecosystem cannot withstand fire. Studies show that forests logged within the past 40 years have more catastrophic fires than untouched forests do. This means it’s critically important to maintain intact ecosystems surrounding UNESCO World Heritage Sites.

Ecosystem of the Great Barrier Reef

In the turquoise waters off the eastern coast of Australia lies the world’s largest living structure, the Great Barrier Reef. Three thousand coral structures have created a colorful colossus the size of Japan. The coral reef may look like a dazzling underwater forest, but it is actually made up of thousands of tiny animals called coral polyps. These polyps are clear, nocturnal, squishy creatures with tiny tentacles. Together, polyps secrete calcium carbonate to create the hard skeleton structure of the reefs.

Coral polyps have a codependent relationship with their food source, a microscopic algae-like organism called zooxanthellae, which live inside the polyps and perform photosynthesis. Through zooxanthellae, a coral gets energy, oxygen, and essential nutrients. These microscopic wonders also give the reef its distinctive bright colors.

The Great Barrier Reef comprises over 600 different types of corals, creating colorful tunnels and towers of various shapes and sizes. All of these nooks and crannies make inviting habitats for thousands of other marine plants and animals. Schools of tropical fish, sea horses, stingrays, sharks, whales, and even the seabirds flying above all depend on the Great Barrier Reef, making it the most biodiverse ecosystem in the whole ocean. In fact, reefs around the 
world make up only 0.1 percent of the ocean’s ecosystems but support 25 percent of all marine life on Earth.

BIGGEST BENEFITS

Not only does the reef support thousands of plant and animal species, its ecological value is estimated at $172 billion. It acts as a barrier that protects Australia from storms and hurricanes, and powers both fishing and tourism that help Australia’s economy.

The Great Barrier Reef experienced the worst bleaching ever recorded in 2016, and another large one in 2017.

The Great Barrier Reef is on top of limestone that is actually fossilized dead corals from thousands of years ago.

Along with the green coloring from zooxanthellae, the super-bright coral colors are caused by fluorescent protein pigments. The coral produce them when they are exposed to sunlight in order to to protect themselves (like sunscreen!).

You can see the Great Barrier Reef from space!

Giant clams can weigh up to 440 pounds and live for over 100 years.

GREATEST THREAT

Global warming is causing the worldwide bleaching of coral reefs. As ocean temperatures rise, heat causes reefs’ food supply, zooxanthellae, to release toxic amounts of hydrogen peroxide. This forces the corals polyps to release their now-toxic food supply. Without zooxanthellae the coral turns a ghostly white color in a process called bleaching. Coral can survive bleaching events only if the temperature cools down before the coral starves to death. If we take actions right now to slow the pace of global warming, we have a chance to protect the world’s reefs.