Geography - Ecosystems

What is an ecosystem?

A natural environment including flora and fauna that live and interact within it.

What is flora, and what is fauna?

Flora are plants, fauna are animals.

What is happening in places with high population?

Cities and farmland are replacing the natural ecosystems.

Define interdependence.

The idea that all species depend on one another in some way.

Define biotic and abiotic components of an ecosystem?

Biotic components are those that are living, while abiotic components are those that are non-living.

What are biotic and abiotic components of ecosystems?

Biotic (living) components include flora, fauna and bacteria. Abiotic (non-living) components include climate, soil and water.

In ecosystems, where does energy come from?

The Sun.

Why do flora and fauna need energy?

To grow and function.

Why are flora known as producers?

They harness the Sun’s energy through photosynthesis in their leaves.

Why are fauna known as consumers?

They eat the flora, and together they form a food chain.

How much energy is lost at each level of the food chain?

90%; the amount of energy that reaches the apex predator is tiny.

How is energy lost in fauna? (4)

• Heat

• bodily functions (such as breathing and movement)

• excretion

• wastage.

What is temperature like in tropical rainforests compared to tundra?

In rainforests, it is hot all year (around 25-30 C). In tundra, it is normally below 10 C.

What is rainfall like in tropical rainforests compared to tundra?

In rainforests, 2500+ mm rain annually. In tundra, there is less than 500 mm rain annually.

What is flora like in tropical rainforests compared to tundra?

Rainforests - tall trees form a canopy. Wide variety. Tundra - wide variety of deciduous trees.

What is fauna like in tropical rainforests compared to tundra?

Rainforests - wide range of birds, reptiles, insects, etc. Tundra - adaped to seasons; some hibernate.

What is the nutrient cycle?

Diagram showing how nutrients travel in a rainforest/ecosystem.

How many stores of nutrients are there and what are they?

There are 3:

• Biomass (living matter - plants)

• litter (dead plant material - fallen leaves)

• soil (weathered rock and organic matter - decomposed plants).

How many inputs are there, and what are they?

There are 2:

• Weathering of rock adds nutrients to soil.

• Input dissolved in rain from the atmosphere

How many outputs are there, and what are they?

There are 2:

• leaching, or loss of nutrients dissolved in water

• surface run-off washes nutrients away.

In the nutrient cycle what happens in the soil-biomass stage?

Plants absorb nutrients from the soil through the roots.

In the nutrient cycle what happens in the biomass-litter stage?

Dead leaves fall from plants.

In the nutrient cycle what happens in the litter-soil stage?

Litter decomposes into the soil.

What is leaching?

Loss of water-soluble plant nutrients from the soil, due to rain and irrigation.

Why do rainforests struggle to recover after deforestation?

Plants in the nutrient cycle aren’t there to absorb the nutrients, so nutrients can’t return to the soil, killing even more plants.

What is the hydrological cycle in rainforests?

Water droplets from previous rainfall are intercepted by vegetation and evaporated. Transpiration from plants releases water too. Causes precipitation in late afternoon.

How many people live in areas with tropical rainforests?

60M people, normally indigenous.

What is shifting cultivation?

A sustainable way of farming in rainforests. Small area of forest is cleared by chopping and burning. Seeds are grown in the clearing, and the ash of burnt trees adds nutrients to the soil. The crops grow well initially, but lose fertility after a couple of years. People move on to to another part of the forest, and the trees slowly re-grow.

Define goods and services.

Goods - products people obtain from the forest. Services - the jobs forests do for us.

What are goods and services of water in rainforests?

Rainforests act as huge filters to purify water. They control water flow, and prevent floods and droughts.

What are goods and services of climate in rainforests?

Rainforests have a cool climate and remove and store 15% of CO2 annually.

What are goods and services of food in rainforests?

• used by indigenous people

• Bananas, pineapples, avocados, cocoa, coffee, nuts, spices, etc.

What are goods and services of health in rainforests?

25% of all medicines come from ranforest flora, such as a drug called vincristine, which increases survival rates from childhood cancers.

What are goods and services of energy in rainforests?

Large dams built on rivers for hydroelectric power, and indigenous people use wood as fuel for cooking and heating.

What is the canopy?

A dense layer of branches and leaves over 30m high, where 60-90% of rainforest life is. Most photosynthesis happens here (greatest amount of sunlight).

Adaptations of the leaves (4)

• Tough, wavy surface to shed water to the forest floor

• A pointed tip at the end called a ‘drip tip’. Allows rainwater to run off easily. Prevents growth of algae and fungus which would block sunlight.

• Leaves grow at different angles to catch the most sunlight.

• Leaves grow large to catch sunlight.

What is the understory?

The lower levels of the forest and the forest floor, where conditions are darker and more humid. Vegetation grows to about 4m high.

What are lianas?

Woody vines rooted in the ground and use other trees to reach the canopy. Once there, they spread out from tree to tree. Can sometimes be over 1km in length.

Why does tree bark not need to be thick in rainforests?

Because loss of moisture and protection from cold weather are not problems in the rainforest.

Why could tree bark be smooth in rainforests?

To prevent other plants, e.g. lianas, from growing on the tree.

What are epiphytes?

Plants which grow on other plants. They don’t take nutrients from the host tree - rather, they get nutrients from the air, rain, decaying organic matter, and waste from animals living on the plants.

What are the human uses of the rainforest? Explain them too (4)

• logging: felling trees for timber. Has been made an industry due to the construction of roads into rainforests. Timber is often exported to Europe and America for furniture and construction.

• Mineral extraction: occurs mostly for gold, copper, and diamonds. Forests and soil removed from large areas. Chemicals used pollute rivers, and drilling for oil and gas leads to air and water pollution. Construction of pipelines, etc., leads to further pollution.

• Agriculture: first, trees are cleared. When soil loses fertility, farmers move to the next area. Most farming done by big companies for soya beans or cattle that clearly vast areas of forest.

• Tourism: an alternative for using rainforests without deforestation. Some nations have made some areas of forest protected where deforestation is banned. Indigenous people involved in protection of forest. Foreign tourists like to visit rainforests, helping local economy.

Place-specific details of Posada Amazonas Ecolodge in Infierno (6)

• Location: nearest city to infierno is puerto maldonaldo. Lodge is on banks of Tambopata river - a tributary of the Amazon - in the Amazon Rainforest, Peru.

• Involved with the ese’eja indigenous community

• Occupies 9500 hectares of rainforest

• Lodge is built from local materials and has 30 fully furnished rooms for guests.

• Private company involved the ese’eja to create a lodge in their traditional homeland. 75% of profits go to the ese’eja, and 25% to the company, called ‘Rainforest Expeditions’

• Local people employed as cooks, cleaners, accountants, guides. Visitors taken around rainforest to see different flora and fauna.

Disadvantages of the Infierno Ecolodge (4)

• difficult to bring benefits of tourism to indigenous people without disrupting their traditions

• improved living standards and medicine causes death rates to fall. indigenous population will grow, so there will be more pressure on the local environment

• if ecotourism becomes more popular, more visitors may have a negative impact on the environment and locals

• to protect tourism industry, regulations are made to prevent locals from using forest resources and their livelihoods may suffer

advantages of the Infierno Ecolodge (6)

• creates a reliable, higher-than-average income for local population. People with tourism jobs have money to buy medicine, send children to school and build better homes

• population can access better-paid jobs and suffer less from disease and illness - better quality of life

• only local materials used - reduces overall environment impact by reducing carbon footprint. Lodge is small-scale to minimise impact

• local population see value in preserving ecosystems and wildlife.

• young people more likely to stay in home area and contribute to local economy and community, rather than moving to urban areas

• local people less likely to be involved in unsustainable farming methods that cause deforestation

What is the Arctic? (4)

• northern polar region - a huge ocean surrounded by frozen land

• winter - ocean is covered in ice.

• summer - rising temperatures causes some ice to melt

• climate change is causing more ice to melt in the summers

What is Antarctica? (4)

• southern polar region - larger than the US

• summer - rarely rises above 0 C.

• scientists live there and tourists visit.

• an international treaty allows scientists of many nations to live together

What is December like in the Arctic and Antarctica, and why?

In December, the South Pole is tilted towards the Sun. Therefore:

• Antarctica gets a full 24 hours of sunlight

• The Arctic is in complete darkness.

What is June like in the Arctic and Antarctica, and why?

In June, the North Pole is tilted towards the Sun. Therefore:

• The Arctic gets a full 24 hours of sunlight

• Antarctica is in complete darkness.

For the Arctic:

• average summer temp?

• average winter temp?

• annual precipitation?

• wind strength?

• less than 10 C.

• from -40 to -20 C

• less than 500 mm

• strong winds

For Antarctica:

• average summer temp?

• average winter temp?

• annual precipitation?

• wind strength?

• from -20 to 5 C

• can reach to -90 C

• around 50mm inland; 200mm on the coast

• windiest continent - katabatic winds

Flora in:

• Arctic

• Antarctica

• southern Arctic - large areas of coniferous forest. Adapted to dry conditions, e.g. dwarf willow and lichens cling to the ground to avoid damage from the strong winds.

• too extreme for many plants to grow. only two grasses found in some places - algae and lichens.

Fauna in:

• arctic

• antarctica

• marine creatures - whales, e.g. narwhal, seals, sea lions, walruses. smaller creatures - midges, insects in summer and boggy areas

• penguins nest on ice shelves - many species migrate north to avoid the extreme cold in winter. marine creatures normally found near the coast - warmer than inland.

What are ice shelves?

A floating extension of land ice. Surrounds Antarctica, covering an area the size of Greenland, 11% of Antarctica’s area. Firmly attached to land.

What are icebergs?

Float all around Antarctica - calve off from glaciers and ice shelves. Range in size from tiny ones to massive ones that helicopters can land on. 90% of icebers’ mass is underwater.

What is sea ice?

Frozen oceanwater surrounding polar regions. Covers nearly 25M km², around 2.5 times the size of Canada. Sea freezes each winter around Antarctica, forming sea ice - however, has been declining by 5.36% per decade since 1985.

What is permafrost?

The part of the ground that remains permanently frozen all year-round. Remains frozen even when temperatures rise above 0 C.

What is the active soil layer?

The upper layer of soil that thaws in the summer.

What is tundra?

treeless ecosystems found in the Arctic and on mountain peaks. Cold, windy, dry climates. covered with snow most of the year - summer brings many wildflowers.

What is taiga?

A biome characterised by coniferous forest - mostly pines, spruces and larches.

Human activities in the Arctic (8)

• Drilling for oil and natural gas

• Tourism

• Mining

• Seed vaults

• indigenous communities

• shipping routes

• fishing / whaling - done by companies and indigenous people

• research

PSD for Baffin Bay Wildlife Sanctuary (5)

• located in Baffin Bay in northern Canada, bordering Greenland

• extends 12nm from coast, and covers 3360km²

• conserves bowhead whales, which feed on zooplankton in two deep offshore troughs

• other animals, e.g. polar bears, narwhals, seals, fish, geese, ducks, benefit from the sanctuary

• community of 1000 Inuits live on the Clyde River, which is in the sanctuary

successes of Baffin Bay wildlife sanctuary (6)

• enables Inuits to maintain traditional lifestyles

• Inuits only hunt small-scale and use all the whale they catch. this is good - bowhead whales breed slowly, so whale numbers remain relatively constant

• Inuits have much better access to medical treatments and medicines - population has increased by 60% in the last decade.

• ecotourism in the area generates income for local people, improving quality of life. Ecotourism in Baffin Bay has generated over $30M for industry. Created many jobs too.

• all commercial fishing, oil drilling, mining and whaling is banned. helps protect and maintain ecosystem and biodiversity of Clyde River.

• tourism raises public awareness of the need to preserve the Arctic wildlife. More donations to charities helps fund protection of the area.

limitations of Baffin Bay wlidlife sanctuary (9)

• scheme only covers a small area, and only protects one out of 17 Arctic species

• noise from drilling in other parts of bay carries through water. disturbs wildlife in Clyde River. oil spills can also damage the ecosystem.

• increased quality of life for Inuits means an increased population, meaning potentially more pressure on natural resources

• climate change caused sea ice in Baffin Bay to melt. sea plankton numbers have also reduced, due to warmer oceans. whales feed under the ice, so this has reduced their population numbers.

• increased ecotourism leads to more pollution, negatively impacting the ecosystem

• rising orca numbers means more bowhead whales have been killed

• Japan and Norway hunt whales using a loophole in the law. more whales are being killed than the population can recover from

• Arctic is remote, so tourists must travel far to get there - large carbon footprint generated

• increased tourism means more ships sailing in the sanctuary, meaning noise from engines and tourists disturb feeding habits of wildlife in the area

PSD of Antarctic Treaty (5)

• an agreement to protect Antarctica

• signed in 1961

• treaty was signed for 50 years (i.e. until 2011). in 1998, it was extended to 2048 with additional environmental protocols added

• 51 countries have now signed the treaty.

• treaty ensures that Antarctica is only for research, no nuclear / radioactive activities, all waste is disposed of without damaging environment, and to protect all flora and fauna.

successes of Antarctic Treaty (4)

• most economic activity is banned

• wilderness protected for future generations to enjoy

• all rubbish from scientific activity at bases is/has been shipped home

• husky dogs banned in 1990s due to risks of cross-species contamination, potentially impacting native wildlife.

limitations of Antarctic Treaty (3)

• some issues have arisen over the little tourism that does happen going wrong and who pays for a rescue mission

• husky dogs replaced with petrol vehicles, increasing carbon footprint and worsening climate change

• treaty cannot protect Antarctica from climate change