Australia and Water

David Radcliffe

University of Georgia

Published in 1994

3-part series on Australian TV in 1998 www.abc.net.au/science/future/default.htm

Tim Flannery is Director of South Australia Museum

Future Eaters

• Part One – An Infinity Before Man– Geology and ecology of Australia before man

arrived

• Part Two – Arrival of the Future Eaters– What happened when the aborigines arrived

• Part Three – The Last Wave– What happened when the Europeans arrived

Early Geology

• Australian continent drifted north as the Earth cooled– Stable climate with very little glaciation– “Did you have a good ice age?”

• Did not collide with other continents– Little volcanic activity or mountain building

• Long stable period (60 million years) produced nutrient-poor soils

www.lonelyplanet.com

Uluruwww.photoway.com/fr/dest/AUST96_30.html

Nutrient-Poor Soils

• Tim Flannery, Taming of the Fire, Australian Broadcast TV– "If you wanna understand the history of this continent

there's no better place to come than here Uluru the timeless rounded features of the rock show that it just hasn't been disturbed for hundreds of millions of years, there's been no volcanoes, no mountain building, no ice age here to rejuvenate this place and as a result the soil here is old, leeched and exhausted all that's left really is just sand."

ENSO

• El Nino Southern Oscillation effect

• 2-7 year cycle of drought and rainfall

• Australia is the only continent where overwhelming influence of climate is not an annual cycle

Under normal conditions, trade winds pile up ocean water to the west and upwelling occurs to the east – warm air rises from eastern Australian

Under El Nino conditions, trade winds weaken, warm water moves back east – dry air descends on eastern Australia

www.pmel.noaa.gov/tao/elnino

Biodiversity

• Theory: greatest biodiversity develops in low-resource (water & soil), stable environments– Organisms survive better by cooperating– Enough time for evolution of organisms that

find a “niche”

• Australia has greater biodiversity than other larger continents– Plant species in Austrlia: 25,000– Plant species in Greater Europe: 17,500

Niche Ecology Examples

• Kangaroo

• Koala bear

• Banded stilt

Kangaroo

• Kangaroo is world’s largest marsupial

• Very efficient energy user– No other animal this big hops– Energy is recaptured in each

bound, in the tendons of its legs – like a pogo-stick

– Each leap pushes its gut back, drawing air into it’s lungs – saving it from using chest muscles to breath

• Female is fertile only during periods of high rainfall Eastern Grey Kangaroo

www.giftlog.com

Koala Bear

• Diet consists entirely of Eucalyptus tree leaves– Lives it’s life in these trees– Leaves are filled with

chemicals to discourage foraging animals

• Very energy efficient– Slow moving like a sloth– Low rate of reproduction– Relatively small brain

• Brain is one of the greatest energy users of all organs

• In man, the brain is 2% of weight but uses 17% of energy

www.giftlog.com

Banded Stilt

• Familiar bird along the coast but never seen to breed

• March 1989 banded stilts disappeared from usual haunts

• About 100,000 birds found nesting near Lake Eyre in South Australia

• Lake was filling to a 15-year high as a result of a period of ENSO rainfall

The Slater Field Guide to Australian Birds

www.lonelyplanet.com

Banded Stilt

• After hatching, the young were tended by the males– Hatchlings left the breeding

area and grew quickly on a rich diet of brine shrimp

– After only 3 weeks the young can fly

• Only 2 weeks after first eggs were hatched, the female was nesting again

• Breeding cycle adapted to ENSO– Can go a decade without

breedingThe Slater Field Guide to Australian Birds

Future Eaters

• Part One – An Infinity Before Man– Geology and ecology of Australia before man

arrived

• Part Two – Arrival of the Future Eaters– What happened when the aborigines arrived

• Part Three – The Last Wave– What happened when the Europeans arrived

Aborigines

• Conventional view– Primitive civilization– Did not develop

agriculture of cities– Nomadic– Few tools– Little impact

Aborigines

• Man evolved first in Africa and spread to other continents– Coevolved with megafauna species still seen today in

Africa– Elephants, giraffes, rhinos, tigers, lions, etc.– Predator-prey arms race

• Aborigines arrived in Australia at least 40,000 years ago– Came by boat from South East Asia

• At the time they arrived there were a number of megafauna species in Australia

Megafauna Extinction

• Megafauna disappeared from Australia shortly after aborigines arrived– Climate or man?

• “The greatest danger that a species faces in a rapidly coevolving ecosystem is the loss of contact with its competitors”

• Megafauna had no defenses against man• Short rich period for aborigines followed by

disaster

Aborigine Adaptation

• Aborigines were the first Future Eaters– Consumed resources more rapidly than they could be

replenished

• “The story of how the first future eaters recovered from this disaster - is one of humanities greatest triumphs”

• Long period (40,000 years) after megafauna extinction for aborigines to adapt– Developed complex relationship with ecosystem

Aborigine Adaptation

• Adapted to make it through the driest periods and take advantage of the wet periods– Did not develop agriculture because it was not

sustainable given ENSO climate– Nomadism allowed aborigines to move to water and

animals– Used fires to recycle nutrients and provide forage for

animals – “fire-stick farming”– Few tools because they had to be mobile– Low population density– Social structure was small tribes

Aborigine Adaptation

• Challenge was genetics– How to avoid inbreeding when your social unit is a

small tribe and potential partners are few• Solution was great tribal meetings during wet

periods– Gathered in areas where food would be available– Marriages were arranged between members of

different tribes– Elaborate ceremonies renewed bonds between tribes– Exchanged information on resources

• Aborigine religion codified rules and was the knowledge base

Aborigines

• Revised view– Highly evolved

civilization– Nomads because

agriculture was not sustainable

– Few tools because these reduced mobility

– Elaborate knowledge of ecosystem embodied in religion

– Large impact

Future Eaters

• Part One – An Infinity Before Man– Geology and ecology of Australia before man

arrived

• Part Two – Arrival of the Future Eaters– What happened when the aborigines arrived

• Part Three – The Last Wave– What happened when the Europeans arrived

Arrival of Europeans

• First contact occurred in 1688 with large number of Europeans arriving in early 1800’s

• Aborigines suffered massive die-offs– Some killed in conflicts– Most killed by European diseases– Typhus, influenza, small pox, measles, etc.

• Why didn’t the reverse happen?– Why didn’t Europeans die of aborigine diseases?

European Diseases

• Guns, Germs, and Steel by Jared Diamond• Most powerful diseases develop where you

have:– High population densities– Contact with herding animals (source of diseases)– London a huge breeding ground for disease– Europeans developed some resistance to these

diseases and survived

• When Europeans arrived on other continents locals had little resistance and died

European Development

• Australia was used first as a place to send convicts from overflowing English debtor prisons– 1788 to 1868– Farms were developed to feed prison

populations

• Gold was discovered in 1851 and large-scale immigration from Europe began

European Development

• Second episode of “future eating” occurred• English settlers first thought that Australia was a

rich “new land”– Biodiversity– Extensive forests– Vast continent

• Applied European agricultural practices• Extensive cutting of forests for timber and to

clear land for agriculture– Led to erosion and loss of native species

European Development

• Settlers moved inland from the eastern coast in search of better farm land and rivers

• Found some small areas of fertile soils where limited volcanic activity occurred but no big rivers

• Water supplies were limited by ENSO cycles• Settlement expanded during wet years, failed

during dry years

European Development

• Introduced invasive species– Rabbits (24) introduced in 1859 for hunting

purposes and exploded in number– Same thing happened with foxes– Only the wild dog (dingo) was a predator of

rabbits and foxes, but settlers saw the dingo as a pest and killed it off

Agriculture Today

• Still trying to adapt to harsh conditions• Extensive irrigation systems have been

developed that take water from rivers• Results have been saline soils and rivers and

low stream flow– Crops use less water (lower year-round ET) than

native vegetation– Combination of irrigation and lower ET has raised

water tables– Groundwater is high in salt and now poisons the soil

and rivers

Water Management Today

• Australia today is taking a hard-look at how it manages water resources– Discussing what the upper limit might be for country’s

human population (now 40 million)– World leader in the science of “environmental flows”– Set limits on salinity in rivers

• Searching for an alternative to the European model of resource management– Could the aborigine be the new model for living with a

harsh ecosystem?

Future Eating in America

• Many parallels with Australia– 2 cycles of predator

invasions• Clovis point indians• European settlers

– Megafauna & indian extinction

• Important differences– Resource rich continent– Relatively short history– Only now are we reaching

our limits (water)