Antarctic Ecosystem (Cambridge (CIE) IGCSE Geography): Flashcards
Exam code: 0460 & 0976
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- FrontWhat are Ecosystems?
Define ecosystem.
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Cards in this collection (55)
Define ecosystem.
An ecosystem is a biological community of organisms that interact with each other and their physical environment.
What is the difference between biotic and abiotic components?
Biotic components are living things, like animals, plants, fungi and microorganisms. Abiotic components are non-living, such as temperature, light, water and soil.
Define interdependence in an ecosystem.
Interdependence is where species rely on each other for food, shelter, pollination and seed dispersal, which keeps the ecosystem community stable.
Give an example of a small-scale ecosystem.
A garden pond is a small ecosystem.
Define biome.
A biome is a large-scale ecosystem, thousands of square km in size, such as the Great Barrier Reef in Australia.
Why can a change in one component of an ecosystem affect the whole system?
Because species are interdependent, so changes in one component impact other parts. For instance, deforestation will impact the soil, biotic life and climate.
The ______ factors of an area, such as climate, determine the characteristics of an ecosystem by influencing the types of flora that can grow.
The abiotic factors of an area, such as climate, determine the characteristics of an ecosystem by influencing the types of flora that can grow.
List the levels of organisation in an ecosystem, from smallest to largest.
Individual organisms, then populations (groups of the same species), then communities (groups of different species), and finally the whole ecosystem.
Name three materials that ecosystems recycle, and the processes involved.
Carbon, nitrogen and water, recycled through photosynthesis, respiration and decomposition.
True or False?
Organisms in an ecosystem only interact by cooperating, never by competing.
False.
Organisms also compete for resources like light, space, water, food, breeding partners and territory.
Give an example of a large-scale ecosystem.
The Great Barrier Reef, Australia is thousands of square km in size and is a large-scale ecosystem known as a biome.
Where is Antarctica located?
At the South Pole, from 66.5° to 90° south of the Equator, surrounded by the Southern Ocean within the Antarctic Circle.
Antarctica is a polar desert with an annual mean precipitation of approximately ______, falling as snow.
Antarctica is a polar desert with an annual mean precipitation of approximately 166 mm, falling as snow.
Compare the mean annual temperature of Antarctica's coast and interior.
The coast has a mean annual temperature of -10°C, while the interior mean annual temperature is -43.5°C.
Why does Antarctica have permanent high pressure?
The poles have a deficit of solar energy, so the air is cold and sinks, creating high pressure.
Define katabatic winds.
Katabatic winds are strong, unpredictable winds created as cold, dry air flows outwards from the high-pressure interior towards the low-pressure areas at the Antarctic Circle, blowing snow around and reducing visibility.
Define insolation.
Insolation is the amount of energy an area receives from the sun.
Name three key abiotic factors that limit life in the Antarctic ecosystem.
Any three of: extreme temperature (cold), scarce liquid water, strong wind, long periods of darkness (limiting photosynthesis), high UV radiation (thin ozone), and cold, nutrient-poor soil.
How have Antarctic plants adapted to survive?
Most become dormant in winter; they are small and round-shaped for wind protection; they flower and seed during long summer hours, relying on wind for pollination (no insects); and mosses, lichens and algae have simple root systems to absorb water easily.
What is the largest dominant terrestrial animal in Antarctica, and how does it survive?
The Antarctic springtail, a soil invertebrate under 3 mm long. It survives by producing antifreeze proteins that keep its body fluids liquid.
How have Antarctic animals adapted physically to the cold?
Layers of fur and insulating blubber (fat as an energy store), waterproof feathers in birds, short legs and round, squat bodies, and large eyes for seeing prey. Behaviours include penguins huddling to stay warm.
The Antarctic marine ecosystem supports Earth's largest animal, the ______, which can grow up to 29 metres long and eat up to four tonnes of krill a day.
The Antarctic marine ecosystem supports Earth's largest animal, the Antarctic blue whale, which can grow up to 29 metres long and eat up to four tonnes of krill a day.
Why is krill described as a keystone species in the Antarctic food web?
Krill sit near the bottom of the web but play a huge role in keeping the whole ecosystem going. Any change to one species quickly affects the rest: phytoplankton > krill > fish > penguins.
True or False?
In the Antarctic food web, krill are the most important producers at the base of the food chain.
False.
Phytoplankton are the most important producers and form the base of the food chain; krill feed on them and sit above them.
Which two agreements currently ban mining in Antarctica?
The Antarctic Treaty System and the Madrid Protocol.
Which two species are most heavily fished in the Southern Ocean?
Krill and Patagonian toothfish.
Define IUU fishing.
IUU fishing is illegal, unreported and unregulated fishing.
Which body regulates sustainable fishing in Antarctic waters?
CCAMLR — the Commission for the Conservation of Antarctic Marine Living Resources.
Antarctica holds around ______ of the world's freshwater, locked up in the Antarctic Ice Sheet.
Antarctica holds around 60% of the world's freshwater, locked up in the Antarctic Ice Sheet.
How is tourism to Antarctica regulated?
It is controlled as eco-tourism under IAATO (International Association of Antarctica Tour Operators).
How does climate change threaten the Antarctic ecosystem?
Rising temperatures melt ice sheets (especially in West Antarctica), contributing to sea level rise; warming oceans reduce krill; loss of sea ice changes penguin and seal habitats; and positive feedback loops (less ice = more warming) worsen it.
Define bycatch in longline fishing.
Bycatch is the unintentional capture of non-target species such as sharks, seabirds and marine mammals, hooked or entangled in baited lines. It especially harms petrels and albatrosses, which have delayed maturity and low reproductive rates.
How many tourists visit Antarctica each year?
Over 50,000 tourists a year.
How does ozone layer depletion damage the Antarctic food chain?
The ozone hole forms every spring, letting more UV radiation reach the surface. This harms phytoplankton, the base of the marine food chain, so less phytoplankton means less krill and less food for predators. UV also damages the DNA of mosses and microbes.
Define a bottom-up trophic cascade in the Antarctic.
A bottom-up trophic cascade is when a change at the base of the food chain affects the whole ecosystem. For example, falling krill populations cause declines in whales, seals, penguins and fish that depend on them.
Why does melting Antarctic ice increase global warming (the albedo effect)?
Ice sheets have high albedo and reflect sunlight, keeping Earth cool. When ice melts, darker ocean water absorbs more heat, increasing global warming.
True or False?
Many Antarctic species are endemic, meaning they live nowhere else on Earth.
True.
Many Antarctic species are endemic, meaning they live nowhere else on Earth.
What risks does tourism pose to Antarctica?
Risks include disturbing wildlife (e.g. penguin breeding areas), spreading invasive species, and pollution from ships and waste.
Where do most Antarctic tourists go?
Most tourism is concentrated in the Antarctic Peninsula.
When was the Antarctic Treaty signed?
Signed in 1959.
What three activities does the Antarctic Treaty System ban?
Military activity, nuclear testing, and mineral extraction.
Define global commons (as applied to Antarctica).
A global commons is an area that no one owns. The Antarctic Treaty designates Antarctica as a global commons, though several nations have made overlapping, unrecognised territorial claims.
What is the main weakness of the Antarctic Treaty System?
It is highly successful at preventing conflict and resource exploitation but has limited enforcement powers.
What is the Madrid Protocol (1991)?
The Protocol on Environmental Protection to the Antarctic Treaty. It bans mining, and requires Environmental Impact Assessments.
The Madrid Protocol sets out strict environmental rules but will be ______, which may bring political challenges in the future.
The Madrid Protocol sets out strict environmental rules but will be reviewed in 2048, which may bring political challenges in the future.
Define an Environmental Impact Assessment (EIA).
An EIA is a process for evaluating the potential environmental, social and economic impacts and sustainability of a proposed development project, and for developing strategies to mitigate or avoid those impacts. EIAs are mandatory under the Madrid Protocol.
What does CCAMLR do to manage Antarctic fishing?
It manages fishing quotas to prevent overfishing of krill and toothfish, using scientific data to set sustainable levels and protect marine food webs.
What is the main limitation of Marine Protected Areas (MPAs) in the Southern Ocean?
They are good for biodiversity and protect breeding grounds of penguins, seals and whales, but only a small percentage of the Southern Ocean is protected — more MPAs are needed.
How is tourism managed by IAATO?
IAATO sets voluntary rules (e.g. keeping distance from wildlife, limiting ship sizes, landing sites and group numbers).
True or False?
The Madrid Protocol and the Montreal Protocol both deal with protecting the Antarctic environment.
False.
The Madrid Protocol protects Antarctica's environment. The Montreal Protocol deals with substances that deplete the ozone layer and applies globally, not just in Antarctica.
How are scientific research stations encouraged to reduce their environmental impact?
All research must include environmental planning and waste management; stations are encouraged to use renewable energy (e.g. solar panels) and recycle waste. However, infrastructure development still creates localised impacts.
The ban on mineral and resource extraction is effective now, but some countries such as ______ show interest in future exploitation if the rules change.
The ban on mineral and resource extraction is effective now, but some countries such as Russia and China show interest in future exploitation if the rules change.
By how many countries was the Antarctic Treaty signed?
By 12 countries; it now has over 50 signatories.
What does the Madrid Protocol (1991) declare Antarctica to be?
It declares Antarctica a 'natural reserve, devoted to peace and science'.
What is the key weakness of IAATO's tourism management?
Its rules are not legally binding, so compliance depends on the operator.
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