Transcript 4_1_5 potential impacts of environmental threats

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identify and predict the potential impact of
significant threats on society and outdoor
environments.
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Biological isolation of the Aust landmass for
over 40 my
10% of world’s biodiversity
Susceptible to impact of introduced spp
Climate challenge also
Threats to native spp and to society which
relies on productivity of the land
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https://en.wikipedia.org/wiki/Land_degradati
on
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Detrimental changes in land condition due to
humans
Linked to reduction in productive capacity of
land & economic value
Causes
◦ Older farming practices, incl land clearing
◦ Urbanisation
◦ Industrial pollution
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Land degradation has been occurring at an
alarming rate over past 200 years
Threatens OE and reduces the quality &
quantity of productive land
Threatens biodiversity and our capacity to
produce food
Major types of land degradation:
◦ Dryland soil salinity
◦ Soil contamination
◦ Erosion
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Salinity = too much salt in soil/water
Salinity is a major threat to health &
productivity
https://www.youtube.com/watch?v=4DMYqQ
SGMMs
https://www.youtube.com/watch?v=P4pX5W_
WwU4
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Caused by over-fertilising, continuous
legume cropping & wetland drainage
Consequent changes to soil acidity can make
land useless for agriculture or natural
vegetation
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Wind and water erosion are natural however
they are accelerated by:
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Clearing vegetation
Overgrazing
Pest animals eg rabbits
Salinity
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Many spp have been introduced since 1770
Some have had major impacts on OE
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Blackberries
Rabbits
Foxes
Cane toads
Marine pests
Deer, cats
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Over 100 species of introduced plants have been recorded in the Park.
The majority of these are restricted in distribution and present in low numbers, and occur in
association with localised disturbances such as adjacent private property and roads.
The relatively low number of serious infestations is largely a reflection of minimal disturbance
in the past.
A small number of infestations do, however, pose significant threats to the survival and
integrity of native vegetation and wildlife habitat.
Bridal Creeper, Cape Ivy and Dolichos Pea are of great concern because they invade minimally
disturbed or undisturbed bushland and compete successfully with several vegetation types.
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17 introduced vertebrate species have been recorded in the Park (eight mammals and nine
birds). Major problem species include: predators such as foxes, cats and dogs.
Predators have been implicated in the decline of small native fauna; in particular, dog and fox
predation on Little Terns and Hooded Plovers endangers the breeding success of these species.
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Pigs and goats have the potential to become major problems in the Park.
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Introduced in mid- 1800s
Grows vigorously and can infest large areas
quickly – reduces native wildlife habitat
Displaces native species
Provides food and habitat for other
introduced spp (eg rabbits and foxes)
http://www.vicblackberrytaskforce.com.au/v
bt_problem.html
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Introduced with First Fleet for food
Rabbits cause soil erosion, they remove
vegetation & disturb soil.
Economic damage $600 000 000
http://agriculture.vic.gov.au/agriculture/pest
s-diseases-and-weeds/pest-animals/a-zof-pest-animals/european-rabbit/abouteuropean-rabbit
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Introduced in 1940s for sport
http://agriculture.vic.gov.au/agriculture/pest
s-diseases-and-weeds/pest-animals/a-zof-pest-animals/red-fox
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https://www.feralscan.org.au
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https://en.wikipedia.org/wiki/Northern_Pacifi
c_seastar_in_Australia
https://en.wikipedia.org/wiki/Carcinus_maen
as
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Significant & lasting change in weather
patterns over an extended period of time
Natural process due to variations in sun
energy output, Earth’s orbit, volcanic activity
Vs
Anthropogenic climate change = caused by
humans
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Burning of fossil fuels (coal, oil & gas)
has incr conc of greenhouse gases
Carbon dioxide, methane, nitrous oxides
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Global average temp incr of approx 1 degree
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Will have MAJOR impacts on society, OE,
agriculture, human health, water &
infrastructure
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Reduced availability of water
Less snow fall
Melting of ice in polar regions leading to sea
level rise, flooding
Reduction in egg and milk production
Increases in extreme heat days,
Locally,
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Increase in intensity of droughts and floods
Reduction in fish stocks
Increased bushfires
Loss of coral reefs
Species with low adaptability or mobility
facing extinction eg, Mtn pygmy possum
Ecosystems changing as new species appear
and disappear eg sea urchins
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http://www.climatechangeinaustralia.gov.au/
en/
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Average temperatures will continue to increase in
all seasons (very high confidence).
More hot days and warm spells are projected
with very high confidence. Fewer frosts are
projected with high confidence.
Generally less rainfall in the cool season is
projected with high confidence. Changes to
summer and autumn rainfall are possible but less
clear. For the near future, natural variability is
projected to dominate any projected changes.
Increased intensity of extreme rainfall events is
projected, with high confidence.
Mean sea level will continue to rise and height of
extreme sea-level events will also increase (very
high confidence).
A harsher fire-weather climate in the future (high
confidence).
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Development of towns & cities and increasing
populations of urban areas
Rural to urban drift
90% of Aust live in urban areas
Urban sprawl
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Vegetation & biodiversity loss
Water quality, run off issues
Air & soil pollution
Cause heat trap https://en.wikipedia.org/wiki/Urban_heat_island
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Snowy River has had its flow and ecological
health heavily impacted by the building of the
Snowy Hydro-electric Scheme.
The Scheme collects and stores the water that
would normally flow east to the coast and
diverts it through trans-mountain tunnels
and power stations. The water is then
released into the Murray and Murrumbidgee
Rivers for irrigation
Biodiversity has been severely disrupted
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2 500ha of native vegetation lost @ year in
Vic
Logging, agriculture, human settlement (incl
urbanisation), mining