Chapter 24 P4 Flashcards
Antarctica
- Antarctica is the coldest, highest, driest, windiest, and emptiest continent.
- It is almost entirely covered by an ice sheet, which averages 2 km thick.
- This ice sheet contains around 70% of the world’s fresh water.
- The average temperature in Antarctica in the winter is below -30 °C.
- Unlike most parts of the Earth Antarctica has just two seasons, summer and winter - during the summer, many parts of the continent experience 24-hour sunlight - in the winter many parts of the continent experience 24-hour darkness.
Animals present- Antarctica
- All endothermic animals living on and around Antarctica rely on thick layers of blubber to insulate them from the cold.
- These include whales, seals, and penguins.
- For example, the blubber layer on a Weddell seal (Leptonychotes weddellit) can be 10 cm thick.
- The emperor penguin (Aptenodytes forsteri) is the only warm-blooded animal that remains on the Antarctic continent during the winter.
- Females lay one egg in June (mid-winter) and leave to spend the winter at sea.
- The male penguins stay on land, surviving the most extreme winter conditions for up to nine weeks (with no food), keeping their egg warm by balancing it on their feet and covering it with a flap of abdominal skin.
- A few invertebrates live on the continent all year.
- The largest is a wingless midge called Beligica antarctica, although at a body size of around 5 mm it can only be viewed properly under a microscope.
Plants present- antarctica
- Plants can only grow in the ice-free regions (around 2% of the continent).
- Lichens and moss grow in any favourable niche such as in sand, soil, rock, and on the weathered bones and feathers of dead animals.
- Algae are also able to grow in many sheltered areas.
Control of human activities- Antarctica
- With the exception of a few specialised scientific settlements, Antarctica is too cold for people to live.
- However, in the last 100 years increasing numbers of tourists have been visiting Antarctica.
- Most visit the Antarctic Peninsula, accessible from Chile, where the climate is mild in comparison with the rest of the continent, and there is much wildlife.
Although strictly controlled in Antarctica (only allowing visits for a few hours to selected area), human activity has had a number of effects on the continent:
- Planet-wide impacts such as global warming (causing some parts of the coastal ice sheet to break up) and ozone depletion, caused by human activities elsewhere.
- Hunting of whales and seals, and fishing of some Antarctic species, has depleted stocks of these organisms.
- Soil contamination, particularly around scientific research stations.
- Discharging of waste into the sea, including human sewage.
The Antarctic treaty was established in 1961 to protect the unique nature of the Antarctic continent. This treaty remains in force indefinitely. Some of its provisions include:
- scientific cooperation between nations
- protection of the Antarctic environment
- conservation of plants and animals
- designation and management of protected areas management of tourism.
Snowdonia National Park, Wales
- Snowdonia National Park covers 2000 square kilometres of countryside in north-west Wales.
- It contains the highest mountain range in England and Wales, with four peaks over 1000 metres (including Mount Snowdon at 1085 m).
- The rugged terrain includes lakes and fast-flowing rivers, and wide tracts of ancient woodland and heath.
Animals present - Snowdonia
The rich diversity of habitats in the region provides homes for a wide range of birds. These include:
- Coast and estuary birds such as choughs, cormorants, and oystercatchers.
- Forest birds such as pied flycatcher, redstart, and wood warblers.
- Moorland and mountain birds such as ospreys, buzzards, and sparrowhawks.
There are also over 40 species of land mammal present in Snowdonia including badgers, voles, deer, and hedgehogs.
Plants present- Snowdonia
- Snowdonia supports an equally diverse range of plant species.
- For example, if you climb to the top of Mount Snowdon you may come across the Snowdon lily (Gagea serotina) and other hardy arctic-alpine plants that have evolved to cope with extreme conditions.
- Lower down the slopes, the mountain is fringed by woodlands of oak, alder, and wych elm.
Control of human activities
- Snowdonia National Park was created in 1951 to conserve the biodiversity of the region.
- The Park is home to over 25 000 people, many of whom work on the land.
- It also attracts several million visitors each year.
- Climbing, walking, cycling, and watersports are some of the most popular activities.
The key purposes of the Park authority are to:
- Conserve and enhance the natural beauty, wildlife, and cultural heritage of the area.
- Promote opportunities for the understanding and enjoyment of the special qualities of the Park.
- Enhance the economic and social well-being of communities within the Park.
The Dinorwig power station
- is a pumped-storage hydroelectric power station which was built to help meet the demands of the National Grid during sudden bursts of energy requirement.
- To preserve the natural beauty of Snowdonia National Park, the power station itself is located deep inside the mountain Elidir Fawr, inside tunnels and caverns.
- This has minimised the impact to the environment whilst meeting the human demand for energy.
The Lake District, England
- The Lake District is England’s largest national park, at over 2292 km2
- The national park contains Scafell Pike, England’s highest mountain, and Wastwater, its deepest lake.
- Terrain within the park includes regions of moorland and fell, and includes 16 lakes dammed by glacial moraines (soil and rock debris) around the end of the last ice age.
- The dales and fringes of the lakes provide a rich variety of habitats, including areas of ancient woodland.
Animals present- Lake District
- The varied landscapes of the Lake District provide homes for a wide range of wildlife.
- These include water voles, natterjack toads, and a number of species of bat, through to red deer and birds of prey such as the golden eagle and osprey.
- A number of native species are under threat including the red squirrel and the vendace, a species of fish that is only found in this region, and which appears on the IUCN endangered list.
Plants present- Lake District
- In the central fells, there are habitats that exist above the tree line.
- These are rare in the UK and they support a diverse range arctic-alpine plant communities.
- These include such species as purple saxifrage and alpine cinquefoil.
- Specialised trees have evolved in these harsh habitats, such as the dwarf juniper and dwarf willow (Salix herbacea).
- Lower regions of the Lake District are home to the sundew (Drosera rotundifolia), one of the UK’s few carnivorous plants.
- Insects are trapped within its leaves by a sticky mucilage (which glistens like morning dew, hence its common name) - enzymes are then secreted to digest the insect, releasing its nutrients for the plant.