7.2 Flashcards
How does the biosphere provide food?
Indigenous people get food directly from plants and forest.
How does the biosphere provide medicine?
Lots of plants have medicinal properties that can cure illnesses and keep people healthy. Plant species from tropical forests have created over 7000 drugs
How does the biosphere provide building materials?
Eg. Pine from taiga is used to make furniture and to build houses
Sap from trees can be used as glue. Plant fibres can used to make rope.
How does the biosphere provide fuel?
Indigenous rely on plants and animals for fuel for cooking and warmth. Wood, moss, dried grass and dried animal dung is burnt as fuel.
How do humans exploit the biosphere for energy?
Demand for energy is increasing - more technology and growing population
Large areas of forest are cut down to grow crops for biofuels, or to build coal mines, power stations
Some areas of tropical f. have been flooded by HEP. Drilling oil and gas in tundra is damaging tundra - melting permafrost
How are humans exploiting the biosphere for water?
Demand is increasing with increasing population. Water resources can be over exploited (arid areas like sahara desert). Can cause damage to biosphere, as plants and animals no longer have water
How are humans exploiting the biosphere for minerals?
Demand for minerals such as gold and iron used in building, scientific instruments, electrical appliances etc. is increasing
Extracted by mining. Mines in tropical forests are responsible for deforestation and toxic chemicals are washed into streams and rivers killing wildlife
How does the biosphere help to control the proportion of different gases in the atmosphere?
Plants take in CO2 and give out oxygen during photosynthesis
Animals take in oxygen and give out CO2 for respiration
Why is maintaining the balance of gases in the atmosphere important?
Most living organisms need oxygen to survive
Increased levels of CO2 lead to global warming and acidic oceans (affecting the living organisms)
How does the biosphere help to keep soil healthy?
Plant roots and animals spread nutrients through the soil - maintaining soil structure and fertility, allowing growth.
Roots of vegetation hold soil together, without it soil can be eroded
Vegetation intercepts rainfall to prevent leaching.
How does the biosphere help to regulate the water cycle?
Water is taken up by plants to prevent flooding and soil erosion.
Plants help regulate global water cycle by storing water and releasing it into atmosphere slowly. Can reduce risk of flood or drought a long way away
How does increasing wealth increase demand for resources?
Wealthier people have more disposable income eg. Food spending, cars fridges and television, increasing water use like dishwashers
How does urbanisation increase demand for resources?
Cities tend to be more resource intensive - street lights and neon signs.
Food and water have to be transported long ways to meet demand of cities. Waste needs to be removed
How has industrialisation increased demand for resources?
Manufacturing goods such as cars, electrical appliances uses a lot of energy. Manufacturing also uses a lot of water
Increasing production of processed goods. This increases demand for ingredients such as palm oil, which are found in huge plantations.
What is malthus’s theory
He thought population was increasing faster than supply of resources. When there are too many people for resources, he thought catastrophe will strike till the point where the population would return to the level that can be supported
