Biome= A large ecosystem (plant and animal community) covering a large amount of the earth s surface.

Transcription

1 Topic 3: Battle for the Biosphere What is the value of the biosphere? Define the terms eco-system and biome, and map the distribution of major biomes across the planet. See map above for biome distribution. Ecosystem= A community of plants and animals. Biome= A large ecosystem (plant and animal community) covering a large amount of the earth s surface. 1

2 What effects the distribution of global biomes including climate as well as other localised factors? Factors affecting biome distribution: Latitude- The equator receives the most solar radiation (and places further away from the equator therefore receive less solar radiation). This means the equator is warmest; the further away from the equator a place is the coller the temperatures tend to be and the less plant growth there is (as the solar radiation helps plants to grow). This is why there are no plants at the North Pole and the South Pole. Continentality- Land is quick to heat and quick to cool. Water is slow to heat and slow to cool. Continental places, far inland, have greater temperature extremes. Coastal regions have less extremes of temperature. Altitude- The atmosphere is thinner at higher altitude. Temperature is 1 degree C colder for every 100m of altitude. At high Altitudes few plants will grow due to the cold. Temperature-Global temperature is largely regulated by latitude but can also be determined by continentality and Altitude. Optimum temperatures are between 6-30 degrees and life thrives between these temperatures. Temperatures higher or lower than these figures make life difficult. Precipitation-Around the world precipitation is more likely in some places than others. Where air is forced to rise (low pressure) i.e. at the equator or midlatitudes rainfall is common all year round and forests grow. Where air sinks (high pressure) there is little or no rainfall and deserts form. In between we have areas that have wet and dry seasons like Savannah. Geology- porous or permeable rocks like limestone and sandstones create dry conditions. This limits vegetation growth as there is a lack of water. Impermeable rocks like clays or granite trap water and allow tree growth. Relief- Slopes which face the sun will be warmer than those which face away. South facing slopes are warmer in the northern hemisphere. Drainage- areas that are poorly drained by rivers reduce growth e.g.: bogs/marsh. During times of flood there can be an impact on the Biome. 2

3 How does the biosphere acts as a life support system, and produces a wide range of goods and services? Life Support System The hydrological cycle needs trees and plants to intercept water so that it does not all reach the river at the same time (as this causes floods). Plants absorb carbon dioxide (which causes global warming) and make oxygen (which we need to breathe). Dead plants and leaves put vitamins into the soil, plants burrow helping to aerate the soil; without plants and animals we wouldn t have good soil to grow crops in. Good and Services Cocoa Rubber Bananas Brazil Nuts Pineapples Sugar Many medicines Animals for drug tests Ecotourism Endangered animals Cosmetics Colourings for lipstick Timber Plants Tourism Pets 3

4 Explain how the biosphere regulates the composition of the atmosphere, maintains soil health and influences the hydrological cycle. Regulating the composition of the atmosphere- trees absorb carbon dioxide and store carbon. They also give off oxygen. This means the atmosphere has less carbon dioxide and more oxygen than if there were no trees. Maintaining soil health- Dead plants and leaves put vitamins into the soil, plants burrow helping to aerate the soil; without plants and animals we wouldn t have good soil to grow crops in. Influencing the hydrological cycle- The hydrological cycle needs trees and plants to intercept water so that it does not all reach the river at the same time (as this causes floods). 4

5 How might the biosphere be conserved? *You need to compare (say what is the same and what is different) between CITES and National Parks, and the benefits and limitations of each. Small scale management National Parks- are areas of natural beauty protected by law against damage. The Amazon is home to hundreds of thousands of different species. To protect these, national parks and reserves have had to be established. These invite visitors to see the fauna and flora within its natural habitat, while protecting (to some degree) against widespread destruction, illness, and so on. These parks must promote sustainability and make money to remain viable. Every year, they welcome local and international visitors, educating these ones and providing them with the precious chance to experience the diversity of Brazil s natural arena. To enforce national park protection the Brazilian government use satellite monitoring to find areas of deforestation and SWAT teams armed with helicopters and rifles to arrest people damaging these areas. Agroforestry- this is when crops are grown beneath rainforest trees. Although it does mean a loss of biodiversity it protects the soil and some tree species (and animal habitats). This is being used in Kalimantan. Eco tourism- allowing people to visit the National Parks but ensuring they stay on paths, don t use flash photography or drop litter to minimise damage to plant and animal species. Large scale management CITIES- (Convention on International Trade in Endangered species)- An international agreement that it is illegal to buy and sell endangered species of plants and animals including rainforest trees and animals such as jaguars. People doing this can be imprisoned or fined. Debt for nature agreements - Rich countries (like the USA) pay poor countries (like Guatemala) to preserve the rainforest. The USA gain as it is helping with air quality, Guatemala gain money off their debt to the USA. 5

6 How are humans degrading the biosphere? Mining- The Grande Carajas Development in Brazil brought the mining of iron and the construction of aluminium plants to the Amazon rainforest. The trans- Amazonian highway (a big road) was built to access the mines and plants- mining causes chemical contamination of the soil and trees and habitats are destroyed where the ground is dug up to mine. Timber- beautiful hard woods found in the rainforest such as mahogany are chopped down to sell for furniture and hard wood floor. Agricultural Land- forest is being cut down illegally in Brazil by people with no job or home; they clear forest to live on and to grow food. Once the forest is cleared the soil loses its nutrients and plants cannot grow on this land. In Kalimantan this was done over a large area; timber barons sold the logs for profits but then no food would grow because the top soil washed away. How does the biosphere get degraded indirectly? Climate change is impacting the biosphere in a number of ways. Droughts due to climate change are leading to less frequent rainfall in areas that do not usually have changing weather (not even seasonally). This has led to plant and animal deaths and loss of species, particularly between 2005 and Rainforest frogs catch diseases more easily due to the warmer temperatures. Areas of Australian rainforest are experiencing forest fires which spread more easily and start more easily due to warmer, drier weather. These can be started by people but the drier conditions make them worst. 6

7 Examine the challenges of producing sustainable outcomes in economic, social and environmental terms and the possible tensions. For something to be developed sustainably it needs to be economically sustainable (money), socially sustainable (people) and environmentally sustainable (nature). Socially sustainable- for something to be socially sustainable it needs to meet the needs to a country s population now and in the future without resources running out. Brazil has a growing population, many of who are very poor. There is a shortage of land for housing; cutting down the Amazon would make room for these people s homes. However, there are other solutions such as building blocks of flats (which house many people in a small space). Brazil is also short of jobs; clearing the Amazon could allow more farming and mining. Economically sustainable- for something to be economically sustainable it needs to meet the needs to a country to make money now and in the future without resources running out. Brazil has a growing population, many of who are very poor. Cutting down the rainforest and selling the logs would make money but then they would have nothing else to sell. Brazil s government need to find a way to make money now and in the future. Environmentally sustainable- for something to be environmentally sustainable it must not be used in a way nature cannot easily replace what is taken. Projects such as reintroducing animals to habitats (like jaguars) are environmentally sustainable but are expensive and could be dangerous for people. Environmental sustainability is hard to balance with people s social and economic needs. Example of tension: Environmentalists want to preserve the rainforest for tourism and nature (environmental need). Loggers want to create jobs and make money (economic need). Locals want forest clearing for homes and farms. These people would argue as they all have different interests (social need). 7