Battle for the biosphere.

Battle for the biosphere.

1. Distribution of biomes.

   • Definitions.
     • Ecosystem: a grouping of plants and animals that interact with each other and their local environment.
     • Biome: a large ecosystem - a grouping of plants and animals over a large area of the earth.
   • Different biomes.
     • Coniferous forests are at higher latitudes where the Sun's rays are week. Trees are adapted to the cold with needle-like leaves.
     • Deciduous forests have high rainfall and there are seasonal variations in thee Sun's rays. Trees lose their leaves in the cool winters.
     • The tundra is within the Arctic Circle. The Sun gives little heat here and there is little rainfall. Only tough, short grasses survive.
     • Tropical rainforests are mainly found either side of the Equator. The temperature is hot and there is heavy rainfall.
     • Deserts are close the tropics of Cancer and Capricorn. This is where hot dry air sinks down to the Earth's surface and the Sun's rays are concentrated making it very hot in the day.

2. A life-support system.

   • Biosphere - what it does for us.
     • It regulates the gases that make up the atmosphere - plants absorb carbon dioxide and produce oxygen for us to breathe in.
     • It regulates the water cycle - plants slow the flow of water to rivers and filter water to make it clean.
     • It keeps soil healthy for plants to grow - new nutrients are provided by rotting plant material.
   • Goods provided by the biosphere.
     • Food: Fish, meat, fruits, nuts, berries.
       • The pressure to feed large populations has meant that natural vegetation has been replaced with farmland to grow crops such as wheat, corn and rice. Very few communities survive solely on food from the biosphere.
     • Medicines: Vitamin, plants used to make medicines, e.g. quinine from bark, St John's wort, periwinkle.
     • Raw materials: Timber, Bamboo, Rubber, Water, Oil and gas store carbon.

3. Threats to the biosphere.

   • Degradation of the biosphere by human activity.
     • Ways humans destroy the biosphere directly: Deforestation, mining, quarrying, farming, overfishing.
     • Ways humans destroy the biosphere indirectly: Pollution and climate change causing (among other things): - sea temperature rise - seawater acidification - melting of polar ice caps - changes in amounts of rainfall - treeline changes - stress within ecosystems due to rapid change.
   • Reasons for rainforest destruction.
     • 1. Timber used for buildings, furniture and fuel.
     • 2. Creation of agricultural land for growing crops or grazing animals.
     • 3. Mining and quarrying of minerals for construction industry, jewellery, etc.
     • 4. Transport routes.
     • 5. Building human settlements.
     • 6. Building dams and power stations to provide power

4. Management of the biosphere.

   • National parks, UK.
     • Scale: national. Started: 1951 (Peak District first one). What is conserves: ares of national beauty in the UK - 22000 km2 in 15 parks. Why: important for people's leisure, enjoyment and culture and to preserve wildlife and environment. How they are threatened: any development that would degrade the ecosystem, e.g. mining, construction, overdevelopment. Management type: each park has its own authority controlling any new development.

5. Factors affecting biomes.

   • Local factors affecting biomes.
     • Altitude - different plants grow at different temperatures within the same biome. The higher the altitude the lower the temperature.
     • Rainfall - different types and amount of plants will grow in different parts of the biome depending on the amount of rainfall received. Inland areas are usually drier than coastal areas
     • Rock and soil type - this can affect how fertile different areas are within a biome.
     • Distance from the sea - this can affect temperatures and especially amounts of rainfall within the same biome
     • Drainage - swamps and bogs occur where drainage is poor. Fewer, more specialist plants grow in boggy areas

6. Biosphere management.

   • Sustainable biosphere management.
     • - Ensures the ecosystem can recover quickly from any use. - Prevents damage to the environment / ecosystem. - Helps local people to benefit from their environment / ecosystem. - Helps local people to understand why this management benefits them.
   • Possible tensions.
     • Economic – individuals and communities often want to make as much money as possible, and may use the resources in the biosphere to do this. This provides tensions as it may damage or even destroy the environment in the long-term. This would mean it’s not sustainable economically either, and it may harm or exploit other people now or in the future.
     • Social – to be socially sustainable something must not benefit one group / individual at the expense of another, including future generations. It also means consulting people on an equal basis. This can provide tensions because if everyone is to benefit, this may put the environment at risk. There are also economic tensions as some businesses may flourish at the expense of others.
     • Environmental – being environmentally sustainable means not harming natural resources so they cannot regenerate or continue in the long-term. There are economic tensions as people want to make as much money as possible, as well as social tensions as everyone wants to improve their standard of living.