07 Unique Flora and Fauna

8/3/2019 07 Unique Flora and Fauna

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New Millenium Geography P Toovey & M Otter

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7. Unique fora and fora

Biodiversity refers to the range and numbers of plants and animals living in an area. In Australia

biodiversity is under threat today for a variety of reasons. It is not a new threat as Australian fauna

and ora has been altered by humans for 40 000 to 50 000 years. However, the rate of change has

increased dramatically over the last 200 years.

As a result of Australia being isolated from other continents, certain animals developed unique

characteristics which greatly surprised early European explorers and settlers. Koalas, kangaroos,

platypuses, wombats and echidnas were not found in any other part of the world. Many of these

animals today are under threat due to loss of habitat, increased predators including feral pets,

disease, pollution, smuggling and other human disturbances.

Figure 7.1 Koala

Likewise, as areas of forests have been cleared for human occupance in the form of agricultural,industrial or urban activities, certain species have been lost or endangered. Some of the species

were destroyed by indigenous Australians thousands of years ago as the result of res being lit for

purposes such as hunting or defence. Over time species that were re tolerant started to dominate

the landscape.

Figure 7.2 Megafauna (artist impression)


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Figure 7.3 Vegetation has adapted to the regular occurrence of res in Australia

Australias unique fauna developed in isolation. Some examples include the creatures that live in

the desert regions of interior Australia. Adaptations here include the absence of sweat glands and the

extremely efcient working kidneys aimed at excreting concentrated urine. Others simply avoid the

heat of the day or are able to obtain all of their moisture needs by eating insects.

Wombats have developed large stout bodies with stumpy powerful limbs with shovel-like claws for

digging. Koalas have developed forearms and claws adapted for tree climbing.

Other animals could not cope with the changing climate and died out as a result. Amongst these were

the giant marsupials referred to as megafauna. Such beasts included the diprotodon, the procoptodon

and the thylacoleo.

Threats to Australian animals.

Australia has the second highest number of threatened animal species in the world. The World

Conservation Union stated that there are 527 animals, either critically endangered, threatened

orvulnerable. It has the highest number of threatened reptiles and amphibians in the world. Land

clearing and its consequences such as salinisation of both rivers and landscapes are the foremost

threat to the majority of the species on the list.

Figure 7.4. The Lord Howe Island

Woodhen - a successful rehabilitation

program is bringing this species back

from the edge of extinction

critically endangered - considered to be facing an

extremely high risk of extinction in the wild.

endangered -considered to be facing a very high risk

of extinction in the wild.

salinisation - is the build-up of salt within the soil.

threatened - species that are at risk of extinction and

are further classied according to the degree of risk that

they face.

vulnerable - considered to be facing a high risk of

extinction in the wild.


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The two main threats to the survival of Australian species are the loss ofhabitat and the introduction

ofexotic species.

A. Loss of habitat.

This has come about both deliberately and inadvertently as people have spread across the

Australian environment. Disturbances have resulted from the clearing of land for agriculture,mining, construction of roads, railways, airports, industrial, commercial and residential purposes.

Figure 7.5 Construction

of airports can lead to

habitat loss

Some of the animals most affected by this have been koalas due to their limited diet. Much of

the eucalypt forests that provided food for the koalas have been removed. Resident action groups

have been set up in many parts of Australia in order to identify endangered populations of

koalas, especially on major urban outskirts, and subsequently engage in activities to protect these

populations. Refer to the article in gure 7.6.

Figure 7.6

Scientists claim almost 20 000 koalas die each year as the result of land clearing in Queensland.

They state that for every 100 hectares of native woodland, about 2000 birds, 15 000 reptiles and 500native animals would die either immediately or soon afterwards.

Wombats have also taken a heavy toll as highways have been built across their natural corridors,

especially in the area between Goulburn and Cooma. In response to this, special tunnels have been

built in areas that have been identied as signicant corridors for the wombats. These tunnels go

under the highways to reduce the risk of the animals being hit by trafc.

Wombats have the added problems of a slow rate of natural increase due to a long gestation period

and small numbers of offspring, together with a decreasing gene pool as numbers decrease.

Figure 7.7 Snapshot 1. Wollemi Pine

The Wollemi Pine, ofcially known as Wollemia nobilis, was discovered in a remote area of the

Blue Mountains, about 150 kilometres west of Sydney. The extreme wilderness in which it is located

undoubtedly helped it survive until today. David Noble discovered a stand of the trees in 1994 while

on a hiking trip in the area. They are amongst the rarest plants in the world with only 76 mature

plants and about 200 seedlings known to exist. They are at most danger from re or disease.

The trees contain both male and female cones on separate branches. Their strange bark looks like

bubbles of chocolate with multiple trunks and ferny looking leaves growing in spirals. The trees

grow to a height of about 35-40 metres. Seeds from these trees have been taken and propagated by

the Royal Botanical Gardens and trees will be released for sale around the world from 2005-6. More

information can be obtained from www.wollemipine.com.


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B. Introduced species

Any animal or plant that has been brought into Australia from overseas is referred to as an introduced

or exotic species. Many of these have adapted so well to the Australian environment that they have

taken over the habitat or food supply of native animals and plants. The native plants and animals

have thus become replaced by the introduced species. Examples of these include rabbits and cane

toads, blackberry, lantana and bitou bush.

introduced or exotic species those that have been brought into an area from another place, e.g.

rabbits were introduced into Australia from Europe.

Feral dogs and cats have also been largely responsible for the reduction in numbers of many bird

and reptile species, especially on the urban fringes of the large metropolitan centres in Australia.

Figure 7.8 Some animals unique to Australia

Australian sea lion - The largest colony is on Kangaroo Island numbering about 10 000 in total.

Numbers were decimated during the 1800s sealing operations for oil and skins. Fishing nets, plastic

entanglement and the loss of food supply are their greatest threats for survival. The great white shark

is its greatest natural predator. It has a protected status and is not currently at risk.

Spotted-tail quoll -

mainland. Today its survival is threatened largely through destruction of its habitat, trapping andintroduced predators.

Bilby - These are found today only in the northern desert regions of Australia including the Pilbara.

They live in open, arid country of spinifex grasslands and acacia shrublands. The species is

considered threatened.

making. Fierce ghting between members, especially during feeding, leads to the spreading of the

deadly devil facial tumor disease, DFTD, which has killed 50 000 of the species already.

Koala - Mostly found in eucalypt forests and woodlands, their populations have been greatly reduced

rst by hunting, then habitat loss, and also sterility and blindness. Their populations are now at risk

from forest res. See article, gure 7.10.

Eastern Grey kangaroo - Currently they are found through most of the grasslands of eastern

Australia, especially near the forests and woodlands. As forests have been cut down and more

pasture land has been formed their numbers have increased. Today their populations are not at risk

and at times culling needs to occur to reduce their numbers.


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Mountain pygmy possum - These were not discovered until 1966 and are found only in the sub-

alpine areas of Australia. It is the only marsupial to store food for the winter. It is endangered

mainly due to a loss of habitat and fragmentation of habitat due to the ski industry and associated

infrastructure.

Dusky hopping mouse - rst recorded by Charles Sturt in 1854, but not sighted again in NSW until

2003, appearing in sand dunes near Tibooburra in the far north-west of the state. They were thought

to be extinct until this discovery.

Platypus - Platypuses are found in lakes rivers and streams of eastern Australia. After their

populations were reduced initially due to being hunted for their fur, their populations stabilised.

Today they are not at risk, although they are not often sighted in their natural habitats.

Figure 7.9a Dugong and sea turtle on GBR


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Figure 7.9b Snapshot - Great Barrier Reef

1.6 million tourists now visit the Great Barrier Reef Marine Park (GBRMP) each year. About 85%

of tourists visit the Marine Park in the area offshore of Cairns and in the Whitsundays. The basis of

any trip to the reef is usually nature-based activities focused on the coral and other marine life.

In managing tourism of the Marine Park particular attention is given to:

protecting coral reefs and other habitats such as seagrass from anchor damage, poor diving

practices, waste disposal, reef walking and collecting.

protecting turtles and seabirds from disturbance, especially during nesting seasons.

respecting the cultural importance of the GBR to Aboriginal and Torres Strait Islanders.

minimising conicts in access within this multiple use marine park.

informing the community about the GBR and its world heritage values.

encouraging the adoption of best practices within the tourism operations.

assisting the marine tourism industry to contribute to management initiatives and monitoring

programs.

The GBR is the most biodiverse marine ecosystem in the world. It is the home to over 4000 species

of corals, 1500 sh species and thousands of other animal and plant species. It is so rich in life

because of the warm tropical conditions, shallow water and supply of nutrients from the mainland

nearby. Apart from the myriad species of corals and sh, it is also home to two endangered marine

species - the dugong and the loggerhead turtle.

Dugongs, also known as sea cows, graze the sea grasses that grow in the shallow waters of the Reef.

As their habitat shrinks, their numbers are decreasing, leading them to become vulnerable. Other

causes of their demise include entanglement in plastic and collisions with boats.

Loggerhead turtles are found in oceans off the coast of northern Australia, including the waters of

the Great Barrier Reef. They are an endangered species as the result of pollution in their waters, loss

or disturbance of their habitats and shing (both deliberate and inadvertent). These animals are now

protected and are part of a very active research program involving tagging and monitoring.

Figure 7.10 - Ash Wednesday bushres of16th February, 1983.

Drought conditions had existed over southeastern Australia for a number of years and temperatures

on the 16th reached 43oC with relative humidity down to 6%. Over the period of 24 hours, many

bushres burnt the tinder dry vegetation that had been caused by the extended drought.

76 lives were lost along with 340 000 sheep and 18 000 cattle. Also hundreds of kangaroos, wallabies,

possums, and koalas were burnt alive. 351 000 stock were killed along with 520 000 ha burnt, 3700

buildings and 2400 homes destroyed.


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Figure 7.11 Snapshot - The Lord Howe Woodhen is endemic to Lord Howe Island, a part of

NSW located about 700 km NE of Sydney in the south-west Pacic Ocean. Originally described as

common in the early 1800s, the number of Woodhens had declined to 37 by the late 1970s and was

restricted to the high plateau of Mount Gower in the southern mountains of the island.

This heightened concern for the species future and prompted the implementation of a rehabilitation

program. This program included the removal of feral pigs from Lord Howe Island and a very

productive captive-breeding and release program for the Woodhen. As a result of this program,

one of the most successful ever implemented for any bird species, the wild population increased to

between an estimated 220-30 birds by 1997.

However, surveys in 2001 suggested a decline in numbers had recently occurred. A possible reason

for this is a return to normal carrying capacity rates as breeding pairs need about 3 hectares territory

each. (adapted from the NSW NPWS 2001 Draft Recovery Plan for the LHI Woodhen)

endemic belonging to, or found only in a specic area

rehabilitation program a program aimed at restoring the natural state of an ecosystyem and the

interactions that take place there.

carrying capacity the number of animals that a particular area can support in a period of time

without suffering from stress.

Figure 7.12

Fairy penguins have returned to breed in Sydney Harbour at Store Beach and Quarantine Beach at

North Head. The discovery of the colony burrowing on these beaches is the rst sign that attempts toprotect the penguins through exclusion zones is working. The Manly site is one of only two colonies

on mainland NSW. The colony numbers about 60 breeding pairs. The other colony is at Jervis Bay

and has about 70 breeding pairs.


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Activities

1. Why is Australias biodiversity under threat?

2. How did indigenous Australians destroy some species of ora and fauna?

3. Describe the adaptations of some of Australias unique fauna.

4. Explain the difference between endangered, threatened and vulnerable.

5. Name and outline the two main threats to the survival of a number of Australian species.

Give some examples of the impacts that these threats have on particular species.

6. Use Figure 7.7. Why has the discovery of the Wollemi Pine been a signicant nd? What

are the characteristics of this tree?

7. Use Figure 7.8. On a map of Australia locate the habitats of some of the animals which are

unique to Australia.

8. Use Figure 7.9. Explain the importance of the Great Barrier Reef as a marine ecosystem.

9. Describe the management strategies which need to be implemented to minimise the impact

of tourism on the coral reef ecosystem.

10. Use Figure 7.10. How have res impacted upon ora and fauna?11. How is the survival of the Lord Howe Island Woodhen being monitored?

12. Research task - Explain the issue involved with the koalas on Kangaroo Island.

ICT

Design and create a simple database on the Australian states showing their state emblems.

Include ower, animal, bird and any other emblem.

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07 Unique Flora and Fauna