Download File

Changing environments
• As the climate changes
• All ecosystems are affected
• We need functioning sustainable
ecosystems to maintain water quality,
store carbon, dispose of natural wastes,
remove pollination, maintain genetic
diversity
Predictions
• Lots of predictions have been made from various
computer generated models of climate change but all
agree that not all the earth will be affected in the same
way
• Oceans won’t warm as much as the land
• Greatest temp increase will be in northern hemisphere
• Land covered in snow will decrease/ ice at both poles will
reduce
• Heatwaves and tropical cyclones will increase
• More precipitations in the poles
• But less rain in the Mediterranean, parts of Queensland
and Western Australia
WHO WILL SURVIVE!!!
• History tells us climate change has caused
species to die out & Ecosystems
• Arguments as to whether it was pure climate
or humans hunting
That caused some extinctions
• Warmer climates don’t kill
All species-some move
towards the poles/colder-equator
Urbanisation
• Some ecosystems destroyed due to
building/land clearing etc.
• Makes it more difficult for animals to move
away and find new suitable areas
• This destruction has caused reduction in
biodiversity
• Australia has huge diversity in both its plants
and animals many unique just to us
GREAT BARRIER REEF
• Coral very sensitive to minute changes in temp
• Causes severe stress to coral
• Corals depend on relationships with
unicellular photosynthetic protists that live
within their cells- these protozoans provide
nutrition and give corals their colour
• Corals stress- expels the protists- loses colourcalled bleaching-some never recover from this
process
• Coral dies-reefs taken over by Algae
Pictures to follow………
What the protist looks like under a microscope
Other organisms
depend on coral for
food and shelter –
so they die out too
Australian specifics
• KAKADU- changes
•
•
•
to fire regimes, sea levels and
increased storms are results of climate change
The large wet lands in Kakadu –fresh water-home to
some rare and endangered species such as Magpie
geese- have problems- they are often low lying
wetlands and rise in sea levels could increase their
salinity and these and other organisms will either
leave or die.
The ecosystem will change as organisms that can
tolerate higher salt levels move in
Flooding allows weeds to flourish/ ferral animals to
migrate in like toads and water buffalo- these further
destroy original ecosystems
SPECIES ON THE MOVE
• Long Spined Sea Urchin- common in south eastern
Australian waters is moving towards Tasmania
• This could damage shallow reef ecosystems and
the commercial abalone and rock lobster
industries
• Believed to be moving due to a strengthening of
the East Australian current-that carries the larvae
south
CHANGE IN SEA LEVEL
• sea levels have been both higher and lower in the
past than they are today
• If all the ice on earth were to melt seas would rise
about 70 metres
• However climate change models do not suggest this
will happen
• However as most cities are on the coast any rise in
sea level is a concern
• Buildings, unlike animals and earlier humans living on
coastal areas cannot just move inland as the sea risesso huge economic impact could be felt