Section B - Living World Flashcards
The Amazon (tropical rainforest)
~ The Amazon is the largest tropical rainforest on Earth.
~ • It is home to 1000 species of bird and 60,000 species of plants
• 10 million species of insects live in the Amazon
• It is home to 20 million people, who use the wood, cut down trees for farms and for cattle.
• It covers 2.1 million square miles of land
• The Amazon is home to almost 20% of species on Earth
• The UK and Ireland would fit into the Amazon 17 times!
The Amazon (tropical rainforest) causes of deforestation
- Subsistence and commercial farming – subsistence farming is where poor farmers occupy plots of the forest to grow food to feed themselves and their families. They clear forest and then burn it, hence the name slash and burn. They grow crops until the soil is exhausted and then move on. This contributes to deforestation but not as much as commercial farming (Farming to sell produce for a profit to retailers or food processing companies).
~Logging – This involves cutting down trees for sale as timber or pulp. The timber is used to build homes, furniture, etc. and the pulp is used to make paper and paper products. Logging can be either selective or clear cutting. Selective logging is selective because loggers choose only wood that is highly valued, such as mahogany. Clear-cutting is not selective. Loggers are interested in all types of wood and therefore cut all of the trees down, thus clearing the forest, hence the name- clear-cutting. - Road building – trees are also clear for roads. Roads are an essential way for the Brazilian government to allow development of the Amazon rainforest. However, unless they are paved many of the roads are unusable during the wettest periods of the year. The Trans Amazonian Highway has already opened up large parts of the forest and now a new road is going to be paved, the BR163 is a road that runs 1700km from Cuiaba to Santarem. The government planned to tarmac it making it a superhighway. This would make the untouched forest along the route more accessible and under threat from development.
~Mineral extraction – forests are also cleared to make way for huge mines. The Brazilian part of the Amazon has mines that extract iron, manganese, nickel, tin, bauxite, beryllium, copper, lead, tungsten, zinc and gold!
~Energy development – This has focussed mainly on using Hydro Electric Power, and there are 150 new dams planned for the Amazon alone. The dams create electricity as water is passed through huge pipes within them, where it turns a turbine which helps to generate the electricity. The power in the Amazon is often used for mining. Dams displace many people and the reservoirs they create flood large area of land, which would previously have been forest.
the Amazon ( tropical rainforest) Loss of diversity
Many different species of plants and animals die because of deforestation. As plants and animals are closely connected through the food web, this reduces the biodiversity, or variety of species, found in the tropical rainforest.
The Amazon (tropical rainforest) Climate change
The trees and plants of the Amazon Basin absorb carbon dioxide during the process of photosynthesis. If there are fewer trees and plants due to deforestation, then less carbon dioxide is removed from the atmosphere. In this way deforestation contributes to global warming and therefore climate change.
The Amazon (tropical rainforest) economic development
The creation of mines, farms and roads, which causes deforestation, has also led to economic development. The money created from these enterprises allows a country to generate foreign income, which can then be used to pay off debts or be invested in further development projects.
Alaska (cold environment) opportunities
Mineral extraction -Alaska was known as ‘the gold rush state’ and gold still accounts for 20% of the state’s mining wealth, although silver, zinc and lead mining are also very important.
Fishing in Alaska - this is a huge sector and accounts for 10% of all jobs in Alaska, employing 78,500 people, and generating $US6 billion to the Alaskan economy every year, although some of the jobs are seasonal.
Energy development in Alaska - Alaska has more than 50 hydroelectric power (HEP) plants, which generate around 20% of electricity across the state, and is the perfect site for hydroelectric power due to the wide u-shaped valleys that were previously glaciated, with huge rivers running through them.
Tourism in Alaska - Tourism is a huge employer in Alaska, with up to two million people visiting the state each summer, however much of this work is seasonal and poorly paid. The state has numerous national parks, preserved villages, refuges and monuments and there are historical sites for those interested in the Inupiat and Yup’ik heritage. Alaska also offers many other attractions - fishing, seeing wildlife, whale watching and kayaking. There is also hiking, skiing, rock climbing and sightseeing by helicopter. In addition, many adventure tourists visit to experience off-roading, although this has led to all sorts of problems, such as leaving deep tyre tracks through waterlogged ground after permafrost has melted, which takes the land many years to recover from. Around 60% of summer visitors are cruise ship passengers, from ports along the west coast of North America, such as Seattle in the USA and Vancouver in Canada.
Alaska (cold environment) challenges
Extreme temperature -
Very low temperatures and long hours of darkness make building anything difficult
Infrastructure -
. Building roads, railways and pipelines for water and electricity supplies is very difficult on frozen ground that is liable to melt
. Pipelines need to withstand freezing as they cannot be buried underground due to the permafrost
Buildings -
If the permafrost layer begins to melt, the ground will become unstable with possible landslides
Creating solid foundations for buildings is difficult (frozen and unstable ground) making any further development difficult
